Changing climate and the coast report of the Intergovernmental Panel on Climate Change from the Miami Conference on Adaptive Responses to Sea Level Rise and Other Impacts of Global Climate Change

[From the U.S. Government Printing Office, www.gpo.gov]

United Nations World United States Army Corps of May 1990
Environment Meteorological Engineers, Environmental Protection
Programme Organization Agency, National Oceanic and
Atmospheric Administration
Changing Climate and the Coast
9
Volume 1: Adaptive Responses and their Economic,
Environmental, and Institutional Implications

Is, ed.

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Report to the Intergovernmental Panel on Climate Change
from the Miami Conference on Adaptive Reponses
to Sea Level Rise and Other Impacts
of Global Climate Change

Library of Congress Cataloging-in-Pubikadon Data

Changing Climate and the Coast / edited by James G. Titus.
Papers presented at workshop held in Nfiami, Fla, Nov 27-Dec 1, 1989,
sponsored by the US Environmental Protection Agency and others.
Contents: vol. 1. Adaptive responses and their economic, environ-
mental, and institutional implications-vol. 2. Western Africa, the Ameri-
cas, the Mediterranean basin, and the rest of Europe
Includes bibliographical references.
1. Global warming-Congresses. 2. Climatic Changes--Congresses.
3. Sea level--Congresses. 1. Titus, James G. II. United States Environ-
mental Protection Agency.
QC981.8.G56C55 1990 90-2741
333.91'7--dc2O CIP

CHANGING CLIMATE AND THE COAST

VOLUME 1: ADAPTIVE RESPONSES AND THEIR'ECONOMIC,
ENVIRONMENTAL, AND INSTITUTIONAL IMPLICATIONS

REPORT OF THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
FROM THE MIAMI CONFERENCE-ON ADAPTIVE RESPONSES TO
SEA LEVEL RISE AND OTHER IMPACTS OF
GLOBAL CLIMATE CHANGE

U - S - DEPARTMENT OF COMMERCE NOAA
COASTAL SERVICES CENTER
2234 SOUTH HOBSON AVENUE
CHARLESTON, SC 29405-2413
Edited by

James G. Titus
U.S. Environmental Protection Agency

with the assistance of

Roberta Wedge

Norbert Psuty
Rutgers University

Jack Fancher
U.S. National Oceanic and Atmospheric Administration

Property of CSC Library

The opinions expressed herein are solely those of the authors and unless noted otherwise do not necessarily
represent official views of any of the sponsoring agencies or the Intergovernmental Panel on Climate
Change.

PREFACE

Increasing concentrations of carbon dioxide and other gases released by
human activities are expected to warm the Earth by a mechanism commonly known
as the "greenhouse effect." Such a warming could raise the level of the oceans
and thereby inundate low-lying areas, erode beaches, exacerbate coastal flooding,
and increase the salinity of estuaries and aquifers. Changes in temperatures,
precipitation patterns, and storm severity could also have important impacts on
the coastal environment.

In November 1988, the United Nations Environment Programme and the World
Meteorological Organization created the Intergovernmental Panel on Climate Change
(IPCC), and directed it to assess the science, impacts, and possible responses
to global climate change. This report presents the findings of a conference held
in Miami from November 27 to December 1 on the under the auspices of the Coastal
Management Subgroup of the IPCC's Response Strategies Working Group. The Miami
conference focused on the implications of sea level rise for Western Africa, the
Americas, the Mediterranean Basin, and the rest of Europe; a second conference
held in Perth, Australia addressed the other half of the world.

Many people helped in the compilation of this report. Roberta Wedge
coordinated the production. Norbert Psuty provided overall guidance to the
authors of eleven country-specific papers. Jack Fancher rewrote one of the
papers. Sheila Blum, Lou Butler, Karen Clemens, Marcella Jansen, Susan
MacMillan, Joan O'Callahan, Karen Swetlow, and Lim Valianos copyedited the
manuscripts.

John Carey chaired the conference, assisted by session chairpersons Job
Dronkers, Asgar Kej, Randy Hanchey, Ahmad Ibrahim, John Campbell, Ines
Schusdziarra, Thomas Clingan, Chidi Ibe, C.A. Liburd, and Jim Broadus. Tom
Ballentine made conference arrangements; Muriel Cole, Joan Pope, Steve
Leatherman Fatimah Taylor, Charles Chesnutt, and Melanie Jenard also assisted
with the conference organization. V. Asthana, J.R. Spradley, Cate McKenzie,
Peter Shroeder, Katie Ries, and Morgan Rees worked several nights attempting to
ensure that the summary conference report adequately reflected the views
expressed at the meeting. But most importantly, over one hundred researchers
and officials from all six inhabited continents and several island states -- on
short notice -- prepared papers, came to Miami, and initiated a dialogue on how
the nations of the world can work together to meet the challenges of rising seas
and changing climate.

TABLE OF CONTENTS

Page
VOLUME I

CONFERENCE REPORT: Adaptive Options and Policy Implications of Sea Level Rise
and Other Impacts of Global Climate Change . . . . . . . . . . . . . . . . 3

X. PROBLEM IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . 51

Causes of Sea Level Rise . . . . . . . . . . . . . . . . . . . . . 53

An Overview of the Effects of Global Warming on the Coast . . . . . 63
James G. Titus

Reasons for Being Concerned About Rising Sea Level . . . . . . . . 87
Dr. Louis W. Butler

Existing Problems in Coastal Zones: A Concern of IPCC? . . . . . . 95
Robbert Misdorp

Holding Back the Sea . . . . . . . . . . . . . . . . . . . . . . 101
Jodi L. Jacobson

Assessing the Impacts of Climate: The Issue of Winners and Losers
in a Global Climate Change Context . . . . . . . . . . . . . . 125
Michael H. Glantz

11. OPTIONS FOR ADAPTING TO CHANGING CLIMATE . . . . . . . . . . . . 139

Options for Responding to a Rising Sea Level and Other Coastal
Impacts of Global Warming . . . . . . . . . . . . . . . . . . . 141
James G. Titus

Coastal Engineering Options by Which a Hypothetical Community
Might Adapt to Changing Climate . . . . . . . . . . . . . . . . 151
Joan Pope and Thomas A. Chisholm

The Role of Coastal Zone Management in Sea Level Rise Response 161
Marcella Jansen

A Worldwide Overview of Near-Future Dredging Projects Planned in
the Coastal Zone . . . 167
Robbert Misdorp and Rien Boe7je

111. ECONOMIC, ENVIRONMENTAL, LEGAL, AND INSTITUTIONAL IMPLICATIONS
OF RESPONSE STRATEGIES . . . . . . . . . . . . . . .. . . . . . 173

Socioeconomic, Legal, Institutional, Cultural, and Environmental
Aspects of Measures for the Adaptation of Coastal Zones at Risk
to Sea Level Rise . . . . . . . . . . . . . . . . . . . . . . . 175
Job Dronkers, Rein Boeije, and Robbert Misdorp

A. ENVIRONMENTAL IMPLICATIONS . . . . . . . . . . . . . . . . . . 195

Environmental Implications of Shore Protection Strategies Along Open
Coasts (with a Focus on the United States) . . . . . . . . . . 197
Stephen P. Leatherman

Implications of Response Strategies for Water Quality . . . . . . 209
Richard A. Park

Coastal Marine Fishery Options in the Event of a Worldwide Rise in
Sea Level . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
John T. Everett and Edward J. Pastu7a

Impact of Response Strategies on Deltas . . . . . . . . . . . . . 225
James G. Titus

Environmental Impacts of Enclosure Dams in the Netherlands . . . 229
J.G. De Ronde

B. LEGAL AND INSTITUTIONAL IMPLICATIONS . . . . . . . . . . . . . 235

International Legal Implications of Coastal Adjustments Under Sea
Level Rise: Active or Passive Policy Responses? . . . . . . . . 237
David Freestone and John Pethick

Legal Implications of Sea Level Rise in Mexico . . . . . . . . . . 257
Diana Lucero Ponce Nava

Legal and Institutional Implications of Adaptive Options of Sea
Level Rise in Argentina, Uruguay, and Spain . . . . . . . . . . . . 261
Guillermo J. Cano

Preserving Coastal Wetlands as Sea Level Rises: Legal Opportunities
and Constraints . . . . . . . . . . . . . . . . . . . . . . . 269
Robert L. Fischman and Lisa St. Am;n@

State and Local Institutional Response to Sea Level Rise: An
Evaluation of Current Policies and Problems . . . . . . . . . . . 297
Paul Klarin and Marc Hershman

Role of Education in Policies and Programs Dealing with Global
Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . 321
Mike Spranger

C. ECONOMIC AND FINANCIAL IMPLICATIONS . . . . . . . . . . . . . . . 333

Funding Implications for Coastal Adaptations to Climate Change:
Some Preliminary Considerations . . . . . . . . . . . . . . . . . 335
John Campbell

Preparing for Sea Level Rise at the Local Level . . . . . . . . . . 345
James B. Edmonson, IV

Toward an Analysis of Policy, Timing, and the Value of Information
in the Face of Uncertain Greenhouse-Induced Sea Level Rise . . . . 353
Gary W. Yohe

Risk-Cost Aspects of Sea Level Rise and Climate Change in the
Evaluation of Coastal Protection Projects . . . 373
David A. Hoser, Eugene Z. Stakhiv, and Limberios V;Iii;n;s* * * * *

IV. SPEECHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Global Partnerships for Adapting to Global Change . . . . . . . . . 387
John A. Knauss

Luncheon Remarks . . . . . . . . . . . . . . . . . . . . . . . . . 393
John Doyle

vii

CONFERENCE REPORT

ADAPTIVE OPTIONS AND POLICY IMPLICATIONS
OF SEA LEVEL RISE AND
OTHER IMPACTS OF
GLOBAL CLIMATE CHANGE

MIAMI WORKSHOP REPORT TO THE COASTAL ZONE MANAGEMENT
SUBGROUP OF THE INTERGOVERNMENTAL PANEL
ON CLIMATE CHANGE

INTRODUCTION

Since the beginning of human history, a large portion of the Earth's
population has inhabited the coastal zones of the world. Proximity to fertile
coastal lowlands, the richness of the seas, and water transportation have long
been, and still are, the primary motivations for coastal habitation.

Population growth and increasing exploitation of coastal resources are
threatening the integrity of the coastal environment. Moreover, there is a
growing consensus among scientists that the atmospheric buildup of greenhouse
gases could change global climate and accelerate the rate of sea level rise,
which would place further stress on coastal zones. Loss of lives, deterioration
of the environment, and undesirable social and economic dislocation may become
unavoidable.

These circumstances demand political, scientific, legal, and economic
action at international and national levels. It is imperative that such actions
focus on sustainable approaches to the management of coastal resources.

To provide the basis for an internationally accepted strategy to address
climate change, the World Meteorological Organization and the United Nations
Environment Programme established the Intergovernmental Panel on Climate Change
(IPCC) in November 1988, creating working groups to (I) conduct a scientific
.assessment of the magnitude and timing of climate change; (II) assess the
resulting socioeconomic and environmental impacts; and (111) develop response
strategies to limit and/or adapt to climate change.

This report presents the findings of a workshop held in Miami (U.S.A.) from
November 27 to December 1, 1989, under the auspices of the Coastal Zone
Management Subgroup of the IPCC Working Group III. More than 100 scientists and
government officials from 37 nations met to discuss potential strategies to
adapt to sea level rise and other impacts of global climate change, and to
consider the social, economic, legal, environmental, financial, and cultural

implications of such strategies. This workshop focused on the Americas, Europe,
the Mediterranean, and Western Africa. A second workshop in February 1990 at
Perth (Australia) will examine the concerns of other continents and island
nations.

The sections of this report were drafted by the participants in each of the
corresponding workshop sessions during the third and fourth days, with the final
day devoted to a plenary review of the entire report. The following sections
summarize the findings on problem identification; adaptive options; the
environmental, social and cultural, legal and institutional, and economic and
financial (including funding) implications of the adaptive strategies; regional
findings for Western Africa, the Northern Mediterranean and Black Seas, the
Southern Mediterranean, Non-Mediterranean Europe, Central and South America, and
North America. The final section presents general conclusions and
recommendations.

The workshop examined numerous structural and planning approaches.
Although human ingenuity can reduce the effects of sea level rise, the
participants concluded that even the most concerted actions could not eliminate
all of the adverse consequences. Thus, even though the focus of the workshop
was on adaptive options, the participants felt that limiting the buildup of
atmospheric greenhouse gases must be a global priority. Moreover, the burden
of coping with accelerated sea level rise and other consequences of a greenhouse
warming would fall disproportionately on those nations least able to cope with
them. Many participants believe that the industrialized nations have a special
responsibility to assist developing nations in adapting to these consequences.

The participants were unanimous in their conviction that the world urgently
needs to begin the process of identifying, analyzing, evaluating, and planning
adaptive responses and their timely implementation. Even though sea level rise
is predicted to be a relatively gradual phenomenon, strategies appropriate to
unique social, economic, environmental, and cultural considerations require long
lead times. Nature has provided us with some time; the nations of the world
-- collectively and individually -- should use it wisely.

PROBLEM IDENTIFICATION

Coastal zones have high economic values and are rich in natural resources
and amenities, but their environments are often physically hostile. Life on the
coast is already vulnerable to natural forces whose effects could be exacerbated
by an accelerated ri 'se in local sea level. Most shorelines experience
significant and almost constant change, with enormous commercial, recreational,
and environmental values at risk. Each year, throughout the world, lives are
lost, people are injured and left homeless, and tens of billions of dollars' (or
equivalent denominations) worth of property are damaged by storms and other
natural coastal hazards. Flooding, beach erosion, habitat modification and
loss, structural damage, silting, shoaling, and subsidence resulting from
natural factors continue to pose major public safety and economic consequences
and impair many of the intangible benefits derived fromthe coastal zone.

Yet while the risks are substantial, the benefits of coastal resources
significantly outweigh their costs, and thus continue to attract human activity
(Figure 1) . If an accelerated rise in global sea level is added to the
equation, however, the risks to life and property become significantly worse.

Tidal gauge records show that global sea level has been rising I to 2
millimeters per year over the last century. However, according to IPCC Working
Group I, models of the climate, oceans, and cryosphere suggest that sea level
could rise 4 to 6 millimeters per year on average through the year 2050 for a
total rise of 25 to 40 centimeters. The accelerated rise would be due
principally to thermal expansion of the oceans and melting of small mountain
glaciers. Although Working Group I has concluded that the melting of the
Greenland ice sheet could contribute up to 0.37 millimeters per year for every
degree (C) of warming, it estimates that this contribution would be largely
offset by an accumulation of ice in Antarctica sufficient to lower sea level
0.3 millimeters per year per degree of warming. Working Group I believes that
there is so much inertia in global warming that some acceleration of sea level
rise is inevitable.

A rise in sea level would (1) inundate wetlands and lowlands; (2) erode
shorelines; (3) exacerbate coastal flooding; (4) increase the salinity of
estuaries and aquifers and otherwise impair water quality; (5) alter tidal
ranges in rivers and bays; (6) change the locations where rivers deposit
sediment; (7) change the heights, frequencies, and other characteristics of
waves; and (8) decrease the amount of light reaching the sea floor. Local
subsidence can exacerbate all of these effects.

Nature requires coastal wetlands, and the dryland found on coral atolls,
barrier islands, and river deltas, to be just above sea level. If sea level
rises slowly, as it has for the last several thousand years, these systems can
keep pace. Wetlands collect sediment and produce peat, which enable them to
stay just above sea level; atoll islands are sustained by sand produced by
nearby coral reefs; barrier islands migrate landward; and the sediment washing
down major rivers enables deltas to keep pace with sea level. If sea level rise
accelerates, however, at least some of these environments will be lost.
Riverside lands tens of kilometers inland could be as vulnerable as land along
the open coast. The loss of productive wetlands, which act as protective
buffers from the sea and provide crucial habitats for many animal species
important to human society, could be particularly important.

A one-meter rise in sea level could inundate a major part of Bangladesh,
for example; a two-meter rise could inundate Dhaka, its capital, and over one-
half of the populated islands of several atoll nations, including the Maldives
(Figure 2), Kiribas, and the Marshall Islands. Shanghai (Figure 3) and Lagos
-- the largest cities of China and Nigeria, respectively -- are less than two
meters above sea level, as is 20 percent of the population and farmland of
Egypt. In many areas, the total shoreline retreat from a one-meter rise would
be much greater than suggested by the amount of land below the one-meter contour
on a map, because shorelines would also erode (Figures 4 and 5).

Sea level rise would also increase the risk of flooding (Figure 6). The
higher base for storm surges would be particularly important in areas where

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Figure 1. Activity along the coast is increasing in both developing and
industrial nations, as shown in (A) Bombay and (8) Miami.

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Figure 2. Low vulnerable areas: (A) Tulhadoo, Republic of Maldives (note that
the high-water mark is just below the land elevation); (B) in crowded areas such
as Bombay, it is often necessary to build up to the water's edge.

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Figure 3. Much of Shanghai is below sea level.

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Figure 4. The Great Wall of China is already eroding.

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Figure 5. (A) Cliff and (B) beach erosion in Massachusetts.

hurricanes and typhoons are frequent, such as islands in the Caribbean Sea, the
southeastern United States, and the Indian subcontinent. Had flood defenses
not already been erected, London and the Netherlands would also be at risk from
winter storms.

Rising sea level could also degrade water quality. Saltwater would advance
inland in both aquifers and estuaries; and wetlands could become saltier even
if the salinity of adjacent bays did not increase. Moreover, by deepening
shallow bodies of water, sea level rise could cause them to stagnate. Fish
ponds in Malaysia, the Philippines, and China have been designed so that the
tides provide sufficient mixing; deeper ponds would require more flushing to
avoid stagnation.

In atolls, coral reefs supply the sand necessary to keep the islands from
being eroded and inundated. In the long run, any limitation of coral
productivity could increase the risk that these islands will suffer from erosion
or inundation.

In addition to sea level rise, global warming could alter the frequency and
severity of storms; change ocean currents and the resulting local climates;
change the amount of rainfall and hence, the flow of freshwater in rivers; and
alter the wave climatology along shores.

These physical changes could pose a threat to ecological balances and to
the coastal infrastructure, including roads, ports, industrial facilities, and
residential and commercial structures. Populations and land-based activities
could be forced to abandon the inundated areas. The productivity of
agricultural lands adjacent to the coast could be threatened, and the economic
and social culture of small communities dependent upon fishing and related
activities could be severely damaged. As the resources and uses of the coastal
area are affected, secondary social and economic impacts, may be felt both
locally and nationally. Delicate ecosystem balances could be upset, threatening
fisheries, wildlife, and other resources important to mankind.

Finally, there is the question of "winners" and "losers." Changes in
.rainfall and temperature would affect the ability of particular regions to
exploit natural resources. Some would win and some would lose, and additional
analysis of this issue is necessary. In the case of sea level rise, however,
it is difficult to see how there could be any winners at the national level.

ADAPTIVE OPTIONS

In light of these problems, nations should immediately assess the
implications of sea level rise and develop site-specific strategies for adapting
to them. Possible strategies include: (1) defending a site to maintain its
existing uses; (2) adapting in place by modifying structures and various
activities to accommodate rising seas; (3) retreating landward, spending
resources on relocation rather than on coastal defenses; and (4) employing
temporary solutions until escalating economic, social, aind resource costs
require a different approach, at which time one of the three previous options
can be implemented. (The "preventive option" of controlling greenhouse gas

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Figure 6. Urban flooding, such as the 1954 surge in Providence, Rhode Island
(USA), would become more frequent is the sea level rises.

emissions is outside the scope of this report but is the primary focus of two
of the other subgroups of Working Group III.) Although national policies may
encourage one of these approaches, the actual response and its implementation
will often be a local decision.

Types of Adaptive Options

The potential responses to sea level rise fall into three basic categories:
(1) technical, engineering, and structural responses to keep the sea back; (2)

natural or ecological responses to replace lost or damaged resources; and (3)
nonstructural options, which focus on modifying the human uses of coastal lands
and resources. In most situations, the actual response would be a,combination
of these three categories.

Jechnical, Engineering, and Structural Responses

These responses include construction of seawalls, breakwaters, dikes,
levees, tidal barriers, floodgates, and bulkheads; beach nourishment; raising
of coastal land by filling; and stimulation of siltation in deltaic areas. Some
of these responses could be very costly and could resullt in significant
environmental impacts. However, they can be extremely effective at protecting
existing land and structures (Figures 7 through 16). These measures are well
established, have evolved over several centuries, and are colitinuously refined
and improved.

In addition to primary protective works, ancillary engineering works may
be needed to reduce adverse effects. For example, lands currently drained by
gravity may require pumping; and channels may need additional dredging to remove
silt in order to maintain the preexisting flow of freshwater.. To counteract
saltwater intrusion, reservoirs may be necessary to augment 11ow flows.

Natural, Biological, and Ecological Options

These options can mitigate the impacts of rising sea level by replacing
lost resources or by developing alternative habitat areas that could serve
similar ecological functions. Options include creating wetlands and dunes,
stabilizing dunes by planting vegetation, and planting mangroves. Finally, the
productivity associated with coastal habitat losses could be replaced through
aquaculture to compensate for losses in particular fisheries, or to maintain
biodiversity through preservation of endangered species and genetic resourcesi

Nonstructural Options

The simplest approach is to allow coastal resources and land uses to
naturally respond to the changing conditions. If complIete inaction is
unacceptable, nonstructural options can help reduce the risk to property and the
environment by removing structures and directing populations away from
vulnerable areas (Figure 17). Resettlement can be encouraged by regulatory and
legal measures that (1) require structures to be removed, (2) prohibit
rebuilding of structures under special circumstances (e.g., after significant
storm damage), (3) prohibit private construction of bulkheads, or (4) establish
restrictions on new development through zoning or other means to reduce
population concentrations. The fourth approach may be particularly useful; in
many coastal regions it can be justified by existing erosion problems alone.

The process of a gradual. retreat from areas threatened by sea level rise'
may req uire new institutional arrangements to coordinate various levels of
governmental decis.ion making. It wil-1 also require public education'to increase
awareness for all sectors of society about both the impacts of sea level rise
and the implications of various adaptive responses. Additional research is
necessary to develop more effective options.

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Figure 7. (A,B) Manual construction of seawalls to protect Male, capital of
the Maldives. In the background of (B), a Japanese engineering firm
manufactures tetrapods and builds a new breakwater (C).

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Figure 8. Tidal barrier in Japan.

Factors Influencing the Choice of Adaptive Options

While general analyses of response options for various scenarios can be
helpful, the actual choices will be site-specific. The following factors must
be considered for any given coastal, area: the physiography of the area and its
known response to tectonic and isostatic processes; the population density and
its social and economic characteristics; the type and quality of development -
- e.g., industrial,residential, or agricultural; other ecological attributes
and the value of the affected area;the ability of existing institutional
arrangements to plan and implement an appropriate response; the financial
ability and technological resources required to implement the chosen response;

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Figure 9. Shanghai has adap
by installing sliding gates
doorways and other openings

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Figure 10. (A) Groins trap sand moving along the shore. (B) Breakwaters limit
the erosive power of waves.

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Figure 12. Fencing to stabilize dunes.

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Figure 13, Al ong the Dutch coast@, seasonal bu,ildings.1hat are dismantled at the,
end of summer are common.

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Figure 14. Rubbl e consisting of stone, demolished building and highways, and
even Junked cars, are often used to stop erosion, though the aesthetics vary.

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Figure 15. This home is protected by a stone revetment, wire baskets filled
with stones, and sandbags.

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Figure 16. Although elevating structures on stilts diminishes flood damages,
it can have adverse aesthetic impacts on a recreational beach as seen in (A)
Ocean City, Maryland, and (B) Grand Isle, Louisiana (USA).

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Figure 17. Houses are set back from the shore along the coasts of (A) Estonia,
and (B) much of India.
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and the secondary social, economic, and environmental impacts of the chosen
response. All of these factors, which can be quantified or qualitatively
described, must also be viewed in the context of the existing financial and
political situation.

Constraints on Response Capabilities

Implementation of any response will require support from both the policy-
making level of the government and the affected populations. Lack of support
by decisionmakers can result from a lack of understanding of the impacts of sea
level rise and the costs of various types of options. Decisionmakers may also
rank other national or regional problems as having a greater priority. The
effective implementation of a chosen option will also require the coordinated
efforts of a variety of public and private institutions.

Responses will face a number of constraints. Financing may be a critical
problem, particularly where structural options are chosen. Even for
nonstructural options, such as limited retreat, the economic dislocations may
sometimes be unacceptable to policymakers. Finally, many responses will face
legal, environmental, and cultural constraints.

Recommendations for Short-Term Actions

1. The first course of action must be to heighten awareness of sea level rise
and its potential impacts for governments and citizens flike. While many
uncertainties exist, a long-term vision of potential problems should be
incorporated into public and private decision making. Planning efforts
must be flexible to allow future accommodation to changing conditions and
to avoid aggravating existing problems.

2. Governments should support continued research into the causes of climate
change and the likely effect and timing of sea level rise and its impacts.
Establishment of a comprehensive data base, including data and information
on tides, coastal currents, waves, storm surges, areas vulnerable to
erosion and flooding, and other resources at risk, will provide the
knowledge necessary for selecting the most cost-effective response for any
given situation.

3. Because of the global implications of climate change, effective mechanisms
for information exchange and technology transfer among ill nations should
be devel oped. Both between and within countries, special technical
assistance should be offered to all levels of government.

4. International funding mechanisms to support response activities should be
developed.

5. Governments should implement education and public awareness programs to
prepare the population at large to accept the necessary controls and
associated trade-offs, including reducing population density in the coastal
zone.

ENVIRONMENTAL IMPLICATIONS

Most of the fish, shellfish, and sea turtles of the world depend on sandy
beaches, fertile coastal wetlands, marshes, swamps, submerged aquatic vegetation
or unpolluted estuaries for parts of their lifetimes, as do many types of birds
and mammals found in the coastal zone. These areas have high recreational,
cultural, and aesthetic values for many people. Protecting dryland from sea
level rise, however, could have adverse impacts on many of these resources.
This section divides those impacts into three categories: the open coast,
wetlands, and water quality.

Open Coast

Responses along the open coast can, in turn, be broadly divided into three
types: hard structures, soft responses, and allowing shores to retreat. The
last option (no action) has been addressed by IPCC Working Group II and is
outside the scope of this report.

Hard structural approaches can be divided into (1) seawalls and other
measures that physically hold back the sea, and (2) groins, which alter the
deposition of sand. The primary purpose of seawalls is to protect inland areas
from storm damage and inundation without regard to the beach itself. If a
seawall is placed between development and an eroding shore, eventually the beach
wi 11 erode up to the seawal 1 ; some sci enti sts al so bel i eve that such structures
can accelerate erosion. Consequently, a major impact of seawalls is that beach
is eventually lost (Figure 18), removing important habitat for shorebirds, sea
turtles, and other species. By contrast, groins trap sediment moving along the
shore. However, protection of one area is generally at the expense of increased
erosion downdrift from the area protected. Because these structures do not
increase the total sand available to beaches and barrier islands, their long-
term impact is primarily to geographically shift the erosion, not to eliminate
it.

The most common soft engineering approach is beach nourishment, which
involves dredging sand from back bays, navigation channels, or offshore -- or
excavating material from a land-based source -- and placing it on the beach
(Figure 19). Because beach ecosystems are already adapted to annual
erosion/accretion cycles, the placement of sand onto the beach generally has
negligible impacts on beach ecosystems. By contrast, dredging bays can
seriously disrupt shallow-water ecosystems and wetland habitats, a problem that
has already led some nations to effectively stop this practice, except as part
of navigation projects. Although the environmental impacts of dredging offshore
deposits are generally less severe, care must be taken to avoid interference
with coral reefs and 'life in the nearshore zone or altering wave refraction,
which can cause previously stable shores to erode.

Wetlands (swamps, marshes, sea grasses, and shallow waters)

The impacts of adaptive strategies on wetlands can be broadly divided into
deltaic and other wetland ecosystems. In deltaic areas, people might build
dikes along rivers in response to increased river flooding due to sea level
rise. Unfortunately, the resulting "channel ization" of rivers would prevent
annual river floods from providing the sediment and nutrients needed to keep
agricultural lands fertile and to enable deltas to keep pace with sea level rise

iL 4

Figure 18. Although seawalls can protect property, the beach is eventually
lost, as seen in Galveston, Texas (USA).

-00

zjj

Figure 19. While expensive, beach nourishment has already been employed at
Copacabana Beach, Brazil, and other areas with substantial tourism.

and subsidence of the land. Although dikes protect against flooding in the
short run, their long-term impact can be to increase the loss of wetlands and
dryland due to sea level rise, and to decreasing the fertility of farmland. If
dams are built to address water management problems resulting from climate
change, the problem could be further compounded as sediments and nutrients are
trapped upstream (Figure 20).

Protecting dryland from inundation would also contribute to the loss of
nondeltaic wetlands. As sea level rises, most wetland ecosystems could migrate
inland if human activities did not interfere. Bulkheads block the landward
migration of wetlands as sea level rises, decreasing wetland area in the short
run and eliminating it in the long run (Figure 21).

The loss of both deltaic and nondeltaic wetlands would threaten coastal
fisheries. About two-thirds of the fish caught for human consumption depend on
coastal wetlands for at least part of their life cycles; in some areas, this is
true for nearly all species. The loss of coastal wetlands would greatly
diminish these fisheries. In many nations, coastal populations depend on these
fish for subsistence. Because a hectare of wetlands often can provide more food
than a hectare of cultivated farmland, even nations with insufficient arable
.land might sometimes be better advised to allow farmland to be inundated as sea
level rises. The relative productivity of farmland and wetland should be
determined before the decision is made to protect farmland from inundation.

A final response to sea level rise is the creation of marshes and swamps
to replace those that are inundated. Such creation, however, can upset
preexisting habitats. If the wetlands are created by filling shallow waters,
or by excavating terrestrial ecosystems, this response may create one type of
habitat at the expense of another. New management approaches may be required
to consider these trade-offs.

Water Quality

Response strategies can increase the salinity of estuaries and aquifers,
and can cause other pollution problems as well. Perhaps most important, the
pumping of water from areas protected with dikes would increase saltwater
intrusion into groundwater. Moreover, if warmer temperatures or droughts
require increased diversion of water for agricultural, res i dent i al , and
industrial uses, saltwater would migrate upstream in estuaries. This would, in
turn, modify the circulation within the estuary, possibly affecting flocculation
and sediment transport.

Enclosure could increase other water pollution problems by decreasing
flushing. To prevent flooding, areas may be protected with tidal barriers. As
sea level rises, these barriers would be closed more frequently. Initially they
might be closed at every high tide, and eventually during all but low tide.
Reducing tidal flushing would increase the concentrations of pollutants,
endangering fish, wildlife, and adjacent water tables, and possibly creating
health problems. The resulting changes in water circulation and other
properties, such as temperature and salinity, may also harm fisheries.

'410

Ai0,00-*OW,k

Figure 20. Dams and flood control levees block the supply of sediment to
wetlands, resulting in their gradual submersion as seen in Louisiana, United
States.

Figure 21. Bulkheads prevent wetlands from migrating inland as sea level rises.

SOCIAL AND CULTURAL IMPLICATIONS

To a large degree, human existence takes place within a particular social
and cultural framework. Although the lifestyles of one society may seem alien
to another, all cultures should be respected, preserved, and nurtured. While
the industrial nations would face similar physical and environmental impacts
from sea level rise, it is primarily in the developing world -- particularly
small island nations -- where societies and cultures themselves might be
threatened.

Several examples were provided by the representatives from Western Africa,
where there is considerable concern over a wide range of issues related to
success or failure in dealing with sea level rise and other impacts of a
changing global climate. In some circumstances, there may be a need to relocate
people, or even entire communities. This would be a traumatic social process
affecting all social strata and cultures, although in terms of populations at
risk, the most affected may be the poor families. Undertaking such a social
reconstruction would require numerous steps -- from collecting appropriate data
for understanding the implications, to managing a resettlement program and
securing the necessary funding. Doing so must involve understanding of the
physical, social, cultural, and occupational environment of the affected
population, so as to minimize wholesale dislocation and to facilitate the
creation of an environment equivalent to the one being displaced.

The question of resettlement, while exerting major financial demands, also
seriously stresses the social and cultural norms of the community being
relocated. The loss of traditional environments that sustain economic and
cultural bases and provide both subsistence and recreational needs could disrupt
family life and create social instability. This, in turn, would have negative
psychological impacts on entire communities, especially on the young, and give
rise to a number of social evils, including unemployment and drug abuse, with
a devastating social cost to many communities.

Information is being amassed on a worldwide scale from which social,
cul tural , economi c, and envi ronmental impl i cati ons can be deri ved for devel opi ng
countries. An assessment must be made to determine which populations are most
at risk. Thus far, dozens of developing countries with highly populated
lowlands have been identified as being vulnerable.

The social aspects associated with sea level rise and its consequences
could also be severe in the developed world, particularly for certain
subcultures that depend on fishing and other coastal resources. Moreover, the
loss of infrastructure, commercial, and community support systems could be
astronomically expensive as a result of the high value of the installations.
The loss of high-amenity residential areas and of commercial and industrial
activities, and the displacement of skills, are all instances of severe
community loss and replication of expensive investment. Adaptive options can
be constrained by high property values in a free market system and the ability
of the population to afford legal action in pursuit of compensation. Apart from
these exceptions, the negative aspects of sea level rise are applicable on a
global scale, the only real differential being ability to cope in financial
and/or human resource terms. This difference reinforces the need to focus
international attention and assistance on those nations least able to cope with
global warming.

The experience of Venice, Italy, illustrates the response to the 25 cm
relative sea level rise that has occurred over the past 80 years, which is
analogous to the rise facing most of the world in the next 50 years. The
experience gained there with respect to the social and cultural aspects of
responding to sea level rise will have indispensable value for others, such as
the West African countries, in the future.

Educating the populace is fundamental to the success of any future
response. Informing everyone about the impacts of sea level rise and global
climate change -- from children to political decisionmakers -- is essential.
Only then are wise policy decisions possible.

There is an urgent need to implement disaster relief measures to respond
to immediate and sudden sea level rise-induced catastrophes, such as storm
surges and increased hurricane frequency. Postdisaster strategies should form
an integral part of disaster relief strategies. Nevertheless, disaster
avoidance is vastly preferable to disaster mitigation, and prior expenditure on
avoidance measures could well alleviate human misery and show substantial
economic benefits. Legislation as an economic and immediately available option
is recommended to reduce future expenditures on defending lowlands or abandoning
them. Sea level rise is a long-term phenomenon; legislation -- e.g. restricting
the occupation and development of areas at risk -- could produce rich dividends
in the decades to come.

Long-term, research-based, multifaceted educational response strategies in
formal and informal settings therefore constitute an urgent priority.
International and interdisciplinary in scope, these programs should target the
young who are the future managers of the planet and the political decisionmakers
who control the important tools of funding and resource allocation. Programs
that train teachers to train students should be given preference, and all
communication modes should be involved. Developed and developing countries
should mobilize fully to cooperate in providing the material and human resources
necessary to the success of these programs.

LEGAL AND INSTITUTIONAL IMPLICATIONS

The legal and institutional implications of global warming and sea level
rise can be divided into two categories: international and national.

International

The three major internati 'onal issues that the conference identified are (1)
the need to use principles of international law, (2) the potential problems for
marine boundaries, and (3) the use of the precautionary principle.

It is important to use established principles of international
environmental law, including those of the Stockholm Declaration and the World
Commission on Environment and Development Report. An international legal
framework for cooperative response should be established. Such a framework
(whether global, regional, or subregional) could use existing institutions or
establish new institutions. In either case, it should specifically obligate
nations to cooperate in their response to the problems posed by sea level rise

1 28

or climate change and should include provisions for financing, assistance to
developing countries, and transfer of the appropriate technology.

A coordinated approach to the problem of changing maritime boundaries
resulting from sea level rise is necessary. Movements of low-water mark and
disappearance of features used as base points will move the outer limits of
maritime zones -- namely, territorial sea, contiguous zone, and economic zone
(i.e., exclusive economic zone, exclusive fishing zone and, in some cases,
Continental Shelf). Such an approach should address the problems posed by the
complete disappearance of islands, which could alter maritime zones, as well as
changes to other water-related boundaries.

Finally, the precautionary principle (or the principle of precautionary
action) calling for reduction and/or prevention of significant environmental
impacts, even in the absence of conclusive evidence or damage, should be
considered and incorporated, as appropriate, into international agreements.

National

The workshop examined three national issues. First, there will be a need
for coordinated use and improvement of structures, institutions, laws, and
organizations (public and private) that already exist at national, state, or
local levels and that address the issues raised by sea level rise and climate
change. Second, it will be necessary to establish, develop, and/or improve
systems of integrated resource management for coastal zones and related areas.
Such a management system should address conservation and sustainable
development, balance of public/private rights and boundaries, compensation
frameworks, financing of responses, and insurance and other financial
incentives.

Finally, there is a need for research on, and collection of, national laws
as well as comparative studies to identify legal models that nations might wish
to use in developing their legal responses to the problems posed by sea level
rise and climate change.

ECONOMIC AND FINANCIAL IMPLICATIONS

From an economic and financial perspective, the problem of responding to
future sea level rise is one of long-term investment decisions in the face of
uncertainty. Future impacts will depend on human responses: that is, on the
choice of investment options. Investment is a form of deferred gratification
in which the choice is made to pay a price now to obtain future benefits.
Because resources (such as natural resources, human skills and effort, and
capital facilities and equipment) are limited, choices about trade-offs are
unavoidable. Any choice necessarily precludes the use of those resources for
other desirable ends.

A related economic problem concerns the distribution of costs and benefits
among people and across generations. This is the question of who pays, who
benefits, and in what proportions. This is where the issue of winners and
losers arises. Very little attention has been given to this issue, but it must
be recognized as important in attempts to fashion institutional responses.

People have a great talent for adjusting to change, and their adjustments
are often most effective when implemented gradually. Because sea level rise,
its resulting impacts, and the appropriate responses will vary widely across
locales, decisionmakers closest to the facts are likely to devise the most
appropriate incremental responses. In a prescriptive sense, this view tends to
be non-interventionist and favors letting things sort themselves out as the
facts emerge.

For IPCC purposes, however, the value of cooperative study and planning,
and the responsibility of governments and other collective institutions to
anticipate and develop effective responses, should be highlighted. Collective
intervention may be essential when common property is involved and when
decisionmakers ignore the effects of their choices on others. Effects that
cross generations, property lines, or national frontiers arc! obvious examples.
In addition, the lack of incentives for private investment in information
virtually ensures that without governmental sponsorship, too little will be
spent on research and dissemination of information.

Analytic Tools

Methods are being developed to help decisionmakers clarify the relative
cost-effectiveness of potential responses even in the face of enormous
uncertainty. If sufficient resources are available, the appropriate criterion
for ranking potential responses is the "expected present value of net benefits."
This is just the sum of the future benefits of a response option, minus
associated costs, weighted by their likelihood of being realized, and
"discounted" to present value terms. It depends upon (1) the distribution of
subjective probability judgments about future sea level rise, (2) the rate at
which future costs and benefits are "discounted" for comparison with present
values, and (3) the monetary, environmental, social, and cultural cost incurred
by various possible responses. Looking at expectations of when critical
thresholds might be crossed allows one to consider the timing and level of
effort simultaneously with the overall direction the response should take.

"Risk-cost analysis" is a useful framework for making decisions about
adaptive options. This approach combines information on natural sources of risk
and uncertainty -- i.e., storm surge, wave height, and mean sea level -- with
estimates of their physical and economic effects and allows available
information to be incorporated in a model to estimate! the probability
distribution of total costs associated with each adaptive option.

The modeling approach can be especially useful in identifying areas where
additional scientific effort would yield the greatest pa,yoff in terms of
improving decisions. The value of narrowing current uncertainties, particularly
about the rate and magnitude of sea level rise, can then be investigated using
sensitivity analysis.

An additional strength of applying such methods is the emphasis on residual
risks that remain regardless of the adaptive option. This information can help
decisionmakers to avoid choosing options such as an underdesigned dike which
could leave a protected area vulnerable to a catastrophe.

An important limitation of this evaluation process is that the adverse
effects of sea level rise and the costs of adaptive opt-ions may occur at

different times. For monetary values, discounting is an appropriate tool to
compare future costs with current costs. Higher discount rates depress the
estimated cost of future sea level impacts and of future responses. Lower
discount rates make them appear larger. Although it makes good economic sense
to apply some discount rate to future values, this involves strong judgments
about the preferences of society and encounters serious ethical complications
when inter-generational effects are at stake.

In assessing the cost of retreat from sea level rise, some automatic
responses to the risks will reduce the cost of retreat. For example, the demand
for risky shoreside property may decline, leading to reduced property values and
thus lowering the loss from abandonment. The potential for market mechanisms
to decrease the adverse economic and environmental impacts warrants further
exploration. Because market responses will be influenced by other policies
(e.g., the definition of property rights, the availability of subsidized
insurance), exploring their operation will uncover related and important policy
questions that may not presently be part of the climate change dialogue.

Care must be taken to avoid imposing our current understanding (or lack
thereof) of the effects of climate change on the decisionmakers of the future.
We need to begin to understand now the range of options that might be considered
so that the necessary funding and institutional mechanisms can be prepared and
the correct signals can be sent to the relevant institutions. Future decisions
will nevertheless be made based on future information, and a recognition of the
learning process must be incorporated into current activity. The same ranking
criteria applied to assessing the relative merits of various possible responses
can be used to identify the types of information that would be most valuable for
making those future decisions.

Financial and Strategic Planning

The impacts of climate change on coastal areas will not fall evenly across
nations. There will be winners and losers, in both relative and absolute terms.
It is expected that several developed countries will be among the winners
(through economic gains made possible by activities that release greenhouse
gases), while some of the developing nations will be the heaviest losers. Many
of the developing nations will have insufficient financial and technical
resources available for the most desirable adaptive options. In such
circumstances, assistance from industrialized nations may be justified. The
financial burden for assisting developing nations may be very high; it is
important to begin collecting information on the magnitude, timing, and duration
of this assistance and its related costs.

With the present uncertainty over the likely coastal effects of climate
change, implementing expensive adaptive strategies now would be inappropriate.
Emphasis in funding arrangements may be more constructively placed on
facilitating the limitation of greenhouse gas emissions. Again, however,
virtually nothing is known about these relative costs. The value of further
research and improved knowledge must be stressed. Early international
assistance may be most valuable for activities that will improve the
preparedness and ability of countries to adapt to climate change if it occurs,
and that will help even if sea level rise is negligible.

At a local level it may be useful to break down the issues into manageable
components through a process of "strategic planning." The steps of such
strategic planning include a situation audit (data base); an analysis of the
strengths, weaknesses, opportunities, and threats; development of mission
statements based on the outcome of the previous steps; and, finally, an
implementation strategy.

To address the immediate problems of rising relative sea level in Louisiana
(USA), for instance, mission statements and implementation strategies focused
on data base collection, improved communications, education, lobbying and
funding. To help facilitate these tasks, local governments organized,
recruited, and mobilized volunteers, who formed a grass-roots coalition. While
education of the youth was taking place in the school system, the coalition
initiated programs to improve communication, develop a mutual support system,
educate adults and communicate with political decisionmakers.

The driving force behind the subsequent passage of a coordination and
funding mechanism was education. To lobby effectively, it is important to have
a broad-based, educated population making similar demands of politicians. The
nature of the funding mechanism itself is instructive in that it draws its
financial resources from a tax on one of the problem's several causes: the
extraction of petroleum.

WESTERN AFRICA

Owing to the geological evolution of the Western Africa region, the
present-day coasts are mostly low plains, surf beaten, sandy, and, in many
places, subsiding. Most of the large sedimentary basins that make up the region
are separated by cratons that are outcrops of the Precambrian basement; these
constitute the few natural bulkheads in the region. There are considerable
stretches of wetlands, particularly mangroves.

As a result of the present geomorphology and coastal activities, marine
erosion and flooding are prevalent along much of the coastline. These
conditions are causing great ecological damage, and they are disrupting
settlements and socioeconomic structures and activities, many of which are
located on or near the coast.

The protective measures applied at present in the region are very
inadequate when compared to the severity of the problem. If' the predicted sea
level rise occurs, most low-lying areas would be inundated; this would virtually
cripple most economic and social activities. Surface water and groundwater, as
well as the soil, flora, and fauna of the region, would be profoundly affected
as a result of increased salinity and added sediment and pollutant loads. The
fledgling tourist industry could be decimated.

Rising temperature and reductions in rainfall would mean an increased
incidence of heat-related diseases and a drastic reduction in the well-being of
people, livestock, and crops. Hunger and disease would be prevalent and would
increase the present level of human misery.

Sea level rise would increase the need to protect heavily developed areas
with high capital values where relocation is not a reasonable option. But the

excessive costs and technical requirements of some of the proposed adaptive
options to protect such locations are far beyond what the region can afford.
Thus, the region will require effective low-cost, low-technology measures. Such
adaptive options must minimize the dislocation of social and community
structures, avoid interfering with cultural attitudes, and conform with
geotechnical and other environmental considerations.

Outside highly urbanized centers, existing populations should be resettled
and setback lines for any new development on the coast should be enforced.
Where coasts are deemed highly vulnerable, new development must be totally
banned. Where new development becomes imperative, appropriate design criteria
should be adopted to cope with the predicted rise of sea level as well as
increased temperature. Converting coastal lands to forest would dampen wave
energy as well as provide relief from increased heat.

Other adjustments would involve the protection of arable land, improved
management of water resources, introduction of new agro-technology, controlled
land-use policies, maintenance of food reserves, and the introduction of
disaster relief measures.

For protecting arable lands, some of the low-cost, low-technology measures
mentioned above could be applicable. Improved water management techniques could
involve building dams (after an environmental impact assessment), aqueducts,
reservoirs, and irrigation systems, and diverting rivers to husband freshwater.
The adoption of new agro-technology should introduce more salt- and heat-
tolerant crops, development of adaptive irrigation systems for reducing salinity
stress, and conversion of flooded agricultural land for aquatic uses, such as
mariculture.

Although the region is far from being self-sufficient in addressing its
present needs, it will be necessary to stockpile food and institutionalize other
disaster relief measures to cope with the emergencies that may arise from sudden
flooding or drought.

Other adaptive options include setting up environmental monitoring (in
particular tidal gauges) and early warning systems, preparing and providing
flood vulnerability and new land-use maps for coastal areas, and above all,
providing public education and information. This last option requires that more
information be gathered, distributed, and understood.

Public information and education should emphasize the severity of the
anticipated impacts from increased atmospheric temperatures and sea level rise,
and prepare the public for some of the protective, preventive, or adaptive
measures that may be necessary.

The application of most of the adaptive options makes it important that
such propisals be embodied in coordinated and enforceable urban and regional
development plans. Countries in the region should enact comprehensive coastal
zone management policies. The United Nations Environment Programme's (UNEP)
Regional Seas Programme for the West and Central African Region provides a
platform for discussing and institutionalizing such a regional plan. It is
hoped that governments in the region, while pursuing policy options at the
national level, will appreciate more than ever the distinct advantages of a
regional approach to the problems associated with global warming.

In the meantime, data banks of relevant information (providing for
information exchange and transfer) need to be created. There i s also a need
for developing a regional climate change scenario as well as the increased
involvement of regional scientists in global climate-related programs (e.g.,
World Ocean Circulation Experiment, Tropical Ocean and Global Atmosphere
Program, World Climate Research Program).

The above recommendations can be brought to fruition only through sustained
funding by United Nations organizations, potential donor agencies, and national
governments.

NORTHERN MEDITERRANEAN AND BLACK SEA

The coasts of the Northern Mediterranean region have varied topography and
land use. Land use is most intensive in France, Italy, eastern Spain, and parts
of Greece; it is moderate in Yugoslavia, and light in Turkey. The major uses
are summer recreation, maritime cities, harbors, agricultural activities,
lagoonal fishing, and agriculture. With the exception of Turkey, national
populations are not likely to increase significantly, although populations in
coastal zones may grow somewhat.

Areas of High Priority and Concern at Risk From Sea Level Rise

The following types of areas are most likely to be damaged by a rise in sea
level: (1) towns and cities by the sea; (2) harbors; (3) industrial
installations built on lowlands and lagoonal areas; (4) tourist beaches; (5)
pleasure harbors and marinas; (6) coastal "hard" protection works (jetties,
groins, seawalls, etc.); (7) roads, railways, airports by the coast; (8)
lagoonal fishing (due to higher water and salinity levels); (9) coastal sand
barriers and barrier islands; (10) reclaimed lands, usually at sea level, and
associated irrigation systems; (11) desalination facilities; and (12) coastal
archaeological sites.

The present levels of protection of these areas vary. Although there are
stretches of low coast at the margins of agricultural land that are still in a
natural state, defenses against storm wave attack are found throughout the
region, in the form of bulkheads, seawalls, groins, and submerged reefs.

However, in many areas the level of protection is inadequate to prevent
coastline retreat. This problem is particularly evident in areas where dams
have blocked the sediment that rivers would have discharged into littoral
systems. Erosion is also caused by the interference of fixed shoreline
structures, in such places as the Po Delta, and by acceleratE!d land subsidence.
Other problems include the destruction of dunes for construction and the
conversion of wetlands to agricultural and urban areas.

A special situation occurs in the Venice area, where concern for recurring
risk of storm surge flooding has involved scientific, engineering, and political
considerations. Plans for defending the lagoon and safeguarding the historical
city are under way. A tidal barrier designed under government mandate is
expected to be completed by 1997. The project design explicitly considers
global warming: as sea level rises, the gates will simply have to be closed more
frequently.

Impacts of Sea Level Rise

Even the rise of 10 to 25 cm predicted for the year 2030 would magnify the
impact of storm waves and surges and the extent of inland flooding during high
tides, especially in those areas with no current works to protect against
erosion and flooding. The impact on existing hard structures that protect
infrastructures (cities, industrial establishments, communications) would be
minimal in most cases, as they are built to accommodate exceptionally high water
levels during storms. However, if the frequency of exceptional events
increases, in many cases the structures would need to be raised.

A more significant impact is to be expected on water and salinity levels
in canals, estuaries, and lagoons, with an increased frequency of flooding near
the coast and farther inland. In lagoons, even a small rise in sea level would
affect the ecosystems of open waters and marshlands, and particularly, the
management of fisheries and agriculture. Moreover, the upstream migration of
salt wedges would invade agricultural soils and groundwater, threatening the
quality of irrigation water.

A rise greater than 30 cm would magnify these impacts, to the extent that
seafront land uses would have to shift inland or would have to be protected more
extensively (which would require additional protective walls, drainage systems,
and elevation of roads, railways, and other infrastructure). The impacts are
likely to be the least in more sheltered areas that have less attack by waves
(e.g., Yugoslavia, Northern Greece, Albania, and Southern Turkey).

Adaptive Strategies

Technical capabilities and financial resources for structural responses to
sea level rise will continue to be adequate in Italy, France, Spain, and Greece.
In the other countries, this capability will depend on the improvement of
current economic difficulties.

Responses to sea level rise would involve two levels of action: the near
term, while sea level is still rising fairly slowly, and the long run, when
substantial acceleration is possible. In the near term, there will be a
continuation of the present situation, perhaps with a moderate strengthening of
present defenses, and the addition of new ones in some areas.

However, site-specific adaptations have to be considered wherever
protection of a particular land use is no longer cost-effective -- e.g. some sea
resorts and installations at seafront settlements. Such adaptations imply the
shifting of the land uses -- e.g., the abandonment of roads, buildings,
industries, and small 'harbors and the return of some reclaimed lands to the
original lagoonal state, because fishing and aquaculture would be more
profitable than grain cultivation on saline soils.

In the long run, current land use practices would become untenable in an
increasing number of areas. For land uses on low coastlines, the main options
are planned adjustment by means of coastal planning and imposition of
guidelines, or planned retreat of the more exposed areas (mainly deltas) that
are not too developed or heavily populated. Nevertheless, in the many isolated
fishing villages at the bottoms of cliffs in Turkey, and wherever the physical

nature of the coastline leaves little room for retreat, the policy of hard
defenses will have to be continued.

Social acceptability is unlikely to be a major barrier to implementing
adaptive responses. Because the changes would be largely confined to specific
localities, they would be affordable at the national level. In cases where
changes are imposed by sudden catastrophes, the public would often demand
immediate responsive action. When they occur gradually, there would be ample
time for the implications of the response options to be explained to the public.

Recommendations for Priority Action

A number of immediate actions seem to be appropriate:

1. Increase the awareness of the implications of sea level rise for
coastal zone uses and management, especially the awareness of
decisionmakers and politicians. For example, conduct national
seminars and workshops using maximum (though appropriately guided)
media exposure with international support.

2. Identify and further evaluate areas at risk, considering technical
evaluation of the impacts and costs and implications of various
options. Incorporate sea level rise scenarios into all engineering
coastal protection projects.

3. Create, strengthen, or streamline institutions that can carry out
the necessary research and further the legal processes by which
governments can implement policy choices and facil-itate coastal zone
management in the next decades. In most Mediterranean countries,
create study centers on the hazards of climate change at the
interministerial level to advise the government on impacts,
responses, and policies.

SOUTHERN MEDITERRANEAN

Although the Southern Mediterranean is presented separately, the
Mediterranean is one region with a common set of sea level rise problems.
Nevertheless, population patterns and growth will create different challenges
for the northern and southern coasts. While the population along the northern
Mediterranean coast is fairly stable, the southern Mediterranean coast is
experiencing rapid population growth confined to a very narrow zone of usable
land. New urban areas are developing, and existing ones are expanding.

The interrelationship between projected problems due to sea level rise and
problems due to rapid population growth in the limited coastal zone area of
North Africa should emphasized. More than 50 percent of the population in this
area lives within 50 kilometers of the shore, and the coastal zone is expected
to experience significant urban growth over the next 50 years.

Adaptive options for the northern Mediterranean will concentrate on the
preservation of an existing and entrenched infrastructure that is prot,ecting
heavily urbanized areas. By contrast, in the southern Mediterranean, the
adaptive options may be oriented more toward planning and con-trolled community

and urban devel opment. However, this is an interpretive generalization; in
reality, many of the same adaptive options are needed for both coasts.

Many coastal cities have portions at or near present sea level, including
Algiers and Alexandria (Figure 22). Low-lying portions of existing cities,
future plans for urban development, port facilities and small harbors, the
tourist industries' beaches, and aquatic resources in the Red Sea and the Suez
Canal are at possible risk. Port facilities have been designed for existing sea
level rise and could be flooded. Large losses of the freshwater supply as a
result of saltwater intrusion are anticipated as sea level rises.

The two major sections of the Egyptian coast that are most vulnerable to
sea level rise are the east end of the Nile Delta at Port Said and the west end
adjacent to Alexandria. Although Alexandria itself is 3 to 5 meters above sea
level, it is surrounded by low land. Thus, if sea level rises, the city could
become an island.

Long-term tidal gauge records from France and Italy suggest that the
Mediterranean countries have historically experienced 1-2 mm per year of sea
level rise. An accelerated rise in sea level would exacerbate existing local
problems with subsidence, erosion, and storm damage. There are already

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Figure 22. Alexandria's beaches have already eroded.

tremendous erosion problems along the central Nile Del ta and at its
distributary promontories (e.g., the Rosetta). The Nile Delta is experiencing
rapid erosion due to blockage of its sediment supply by the Aswan Dam. Tidal
gauge data from stations located at Alexandria and Port Said document subsidence
in the area of 1-2.5 mm per year. The Algerian-Tunisian shore is particularly
susceptible to wave attack from the west, and this phenomenon could be
exacerbated with a rise in sea level.

The three main adaptive approaches are the same as for other regions: (1)
withdrawing from the coast, (2) building protective structures, or (3) remaining
and adjusting to the expected change.

Regional Recommendations

Improving forecasts of sea level rise is a top priorlity. In addition,
future urbanization should be limited to appropriate areas in view of the
anticipated sea level rise in order to avoid future problems and expense. Plans
for new structures should take into consideration the anticipated rise, and
existing structures will need to be raised as the problem evolves.

Hard protective structures should be constructed where buildings or public
works are at risk. More flexible measures, such as establishing set-back lines
should be used in currently nonurbanized areas. The major difficulty with the
latter option will be to convince officials to accept a loss of precious land
today to prevent some very distant uncertain consequences.

The various stages for the development of response strategies include: (1)
evaluating high-risk areas; (2) developing options (i.e., defensive, adaptive,
retreat) ; (3) defining and developing policy strategies; (4) developing
funding mechanisms; (5) creating appropriate institutional and legal
frameworks; and (6) defining the time frame for implementation.

The regional representative proposed a schedule for responding to sea level
rise and global warming. Over the next 10 years, the focus would be to define
the problem, develop legal structures, and control development. From the years
2000 through 2020, coastal zone planning should define responses and how to
implement them. Adjustment actions, such as retreat, should be initiated. Sea
level rise concerns could be incorporated into current plans for coastal
construction from the years 2020 through 2050.

Country-Specific Recommendations: Egypt

The following adaptive options for Egypt are appropriate today:

1. Upgrade and update the quality of information available on areas
vulnerable to a sea level rise, and use Geographic Information
Systems to analyze it.

2. Adapt new agricultural practices with improved efficiencies for
using freshwater.

3. Develop salt-tolerant agricultural plants.

4. Strengthen existing institutions, and create new ones to deal tilth
water and coastal resource research, allocation, and management.

5. Incorporate a protective plan into the design of an international
road currently planned for the coast.

6. Control the exploitation of quarries along the coast west of
Alexandria in order to preserve the ridge.

7. Incorporate beach erosion studies and erosion control practices into
coastal zone development plans.

8. Move waste dumping sites to suitable locations to reduce risk of
water pollution.

9. Encourage land reclamation projects at higher land elevations.

10. Assess the technical and economic feasibility of bypassing sediments
at the Aswan High Dam.

The consequences of an accelerated sea level rise are not expected to
materialize until 2030-2050. However, the longer the implementation of
appropriate adaptive strategies is delayed, the greater the eventual cost in
human and economic terms. Costs are escalating and the population is doubling,
so it is imperative to work on adaptive activity now.

HON-MEOXTERRANEAN EUROPE

Problem Rdentification

The technical problems related to coastal zone management in Europe are no
different from those found elsewhere in the world. Low-lying coastal areas are
faced with inundation (Figure 23), erosion, saltwater intrusion, and the threat
of extreme climate events, such as the extreme storm surge in 1953 that led to
the collapse of coastal defenses in countries bordering the North Sea (Figure
24).

Anthropogenic problems play less of a role in Europe than in other parts
of the world, as coastal regulations in most countries have existed and have
been enforced for a considerable period of time. The fundamental difference
between most European countries and other countries is that the former have both
the technological and financial resources to respond appropriately to the above
problems.

The present level of coastal defense structures varies among countries.
In countries like the Netherlands, the structures may be considered adequate,
whereas in other countries, such as Poland and Portugal, limited financial
resources constrain coastal protection efforts.

European countries should be able to cope with the possible effects of sea
level rise alone. However, if a relatively steady rate of eustatic sea level
rise is accompanied by changes in the frequency, direction, intensity, and
duration of extreme events (storms), coastal defenses may be insufficient.

some,

Figure 23. Near Helsinki, Finland while the Scandinavian coast is not
vulnerable to erosion, some developed low areas are vulnerable to inundation.

Implementation of Adaptive Strategies

Most.European countries could respond to the threat of sea level rise by,
either coastal defense or retreat. The regional representatives do not see
significant barriers to the implementation of these adaptive strategies. The
financial, technical, and institutional capabilities exist for addressing sea
level rise, particularly with coastal defense measures. Public awareness of the
problem is high, and environmental issues are a priority for policymakers.

Because of the generally high economic, environmental, cultural, and social
values of the coastal areas in European countries, the adaptive measures would
be cost-effective; however, their implementation would depend on site-specific
considerations. For European countries, cost considerations are directly
related to the value of capital investment in coastal areas. In areas where
there is significant investment, there is more incentive to pay the cost of
protection. This is particularly true in highly industrialized countries where
the percentage of coastal defense expenditures is relatively small in relation
.to the gross national product. In less industrialized countries, that

Figure 24. The 1953 flood almost devastated London, Engl and. This picture,
showing what could have happened, was instrumental in creating the public
awareness necessary to construct the Thames Barrier.

percentage could be higher, making the defense option less affordable and less
feasible.

A-high level of technological expertise in coastal defense measures is
readily available in most European countries. In those countries with large
coastal areas that are extensively protected, this expertise is constantly being
improved and expanded.

The institutional framework to facilitate adequate response to the threat
of sea level rise exists in most countries, although in some of them this threat
has not yet been incorporated into the planning and decisionmaking processes.

Because of its long historical experience with flooding and other
catastrophes, the general public is keenly aware of the risks to coastal areas,
particularly-in the countries bordering the North Sea, which have extensive
protective systems. In some countries, the level of awareness probably requires
further stimulation. In all cases, awareness is directly linked to the values
(economic, environmental, cultural, social, etc.) attributed -to the potentially
threatened area. However, at the same time, the public still expects that
provisions for public safety will be continued. Strategies involving any
reduction in safety standards or abandonment of protective systems would be
strongly resisted.

While uncertainty remains concerning the problem of sea level rise, there
would be little or no opposition in European countries to consider or, in some
cases, to incorporate preventive measures into coastal zone management plans in
the light of scientifically acceptable projections for sea level rise.

Although coastal defense can sometimes cause adverse environmental effects,
(see the "Environmental Implications" section) these concerns are increasingly
taken into consideration and have high priority in the national decision-making
processes.

Recommendations

1. Expand climate-related research.

2. Stimulate public awareness about the problem by developing and
providing educational programs.

3. Develop new "tools," such as the Impact of Sea Level Rise on Society
study done by the Netherlands, to encourage a multidisciplinary
integrated response to the threat of sea level rise and all its
implications. Use these tools in the countries where these efforts
have not yet been undertaken.

4. Through international action, facilitate the transfer of developed
technologies to all countries in need of these! "tools," within
European countries and, in particular, within developing nations.

5. Provide international and national assistance for the training of
coastal managers in the European countries that have developed
relevant technologies.

CENTRAL AND SOUTH AMERICA

Problem Identification

The coastal zones of this region face a variety of common problems,
including flooding, elevation of water tables and resulting impacts on
agriculture, increasing population concentrations, inappropriate construction
in low-lying areas, recent intensification of climate anomallies, and ongoing

changes in wave climates, the patterns of littoral drift, and other aspects of
coastal morphology.

These problems would probably be magnified if sea level rises. Flooding
would be exacerbated, causing inland sedimentation problems and silting of river
beds in addition to direct risks to life and property. Coastal erosion would
impede government efforts to develop tourism and other economic activities.
Saltwater intrusion into rivers and aquifers could cause severe problems.
Because many cities discharge sewage into fluvial waters through gravity
drainage systems, a rise in sea level could block the flow of these wastes away
from coastal urban areas. Finally, changes in physio-chemical properties in
coastal waters and flooding of coastal ecosystems could damage the biological
chain, particularly fisheries resources.

Adaptive Strategies and Barriers to Implementation

Existing measures include hard and soft options for shore protection and
preservation of coastal areas. These strategies have been put in place to deal
with existing physical coastal processes (such as wave erosion) and have not
been designed to deal with a rise in sea level.

The representatives from the region see a variety of barriers to
implementing adaptive measures. Perhaps most important, the uncertainty of the
phenomenon and the existence of more pressing socioeconomic problems prevent the
decisionmakers from assigning a high priority to formulation of adaptive
strategies specifically for sea level rise.

Other barriers include cost, the lack of technical and public awareness,
poverty, and the international debt crisis. Countries in the region do not have
the financial resources to invest in adaptive options, given their own
development requirements. Moreover, technical expertise is very limited; there
are not enough knowledgeable people to teach others or address the problem,
given the wide range of competing needs. There is a corresponding lack of
public awareness of the problem that needs to be addressed by formal and
informal educational programs.

Moreover, the poor -- who constitute the majority of people in the region
-- simply do not have the resources to relocate or protect themselves, no
matter how well informed they might be. There are financial problems at the
national level as well: governmental decisionmakers and politicians are
constrained by the pressing need to service international debts, which severely
inhibits national ability to invest in protection of the environment. There are
too many other critical, immediate demands on scarce financial resources.

Adaptive responses also face cultural, institutional, and environmental
constraints. Besides the natural human tendency to resist change, especially
when cultural values and a sense of community are directly related to a
particular environment, different values are placed on the present versus the
future. The present, especially for poor people concerned with basic
subsistence, is immediate and real. The future, which could include a possible
rise in sea level of undetermined magnitude, is too far away and unreal to be

a serious preoccupation, particularly given the existing socioeconomic
constraints.

The greatest factor inhibiting effective institutional response is the lack
of coordination between a variety of disparate agencies, each responsible for
addressing different coastal problems and activities. There is a tendency to
create more agencies or institutions to deal with a problem, rather than to
streamline the existing system to address it more effectively.

Finally, response strategies would undoubtedly have important environmental
implications. Unfortunately, there is not enough knowledge or research data
about ecosystem responses to determine how a particular strategy might affect
the environment.

Effectiveness of Adaptive Strategies

Although adaptive options for this region have not been considered in
depth, the regional representatives recognized that a number of issues would
have to be addressed to evaluate their effectiveness. Maintaining public safety
is important, for example, and the present systems used to protect the coast
from existing problems would be inadequate to cope with an acceleration of sea
level rise.

One must also compare the costs of a strategy with the likely benefits.
The region's representatives concluded that the opportunity cost of investing
in defenses against long-term sea level rise is not currently competitive with
other socioeconomic investment. Another important consideration is the
protection of environmental and cultural resources. Unfortunately, in some
cases, sea level rise has not even been recognized as a possible threat to these
resources.

Finally, given our inability to predict the future, strategies that perform
well under uncertainty should be preferred. But the regional representatives
felt that until preliminary assessments of the impacts and possible responses
are undertaken, an evaluation of this criterion is at best premature and
probably irrelevant.

Reconmendations

Despite of the limitations of current understanding, the regional
representatives concluded that existing knowledge is sufficient to support a
number of recommendations at the national and international levels.

National Level

1. Create local and regional panels on climate change to advise
national authorities. At the national level, there should be a
centralized authority dealing specifically with global climate
change.

2. Create and fund formal and informal education programs on climate
change and sea level rise, and establish information systems tLo
maintain a high public profile for these issues.

3. Develop appropriate technology for adaptive options specifically
related to local conditions.

4. Reallocate funding from reduced military expenditure to address the
physical and social aspects of environmental issues.

5. Encourage national earth science agencies and institutions to place
a high priority on the study of global climate change.

International Level

1. Expand the global monitoring network for the collection and
dissemination of data relevant to sea level rise and climate change,
including the establishment of data banks.

2. Increase the transfer of appropriate technology related to adaptive
options.

3. Reall6cate some military expenditures to assist developing countries
in addressing the physical and social aspects of environmental
issues.

4. Establish regional cooperation/coordination regarding global climate
change.

5. Create and fund formal and informal regional educational programs
on global climate change and sea level rise, including the training
of human resources necessary to support a comprehensive defense
approach to the effects of sea level rise.

6. Make available the latest state-of-the-art data in research and
appropriate adaptive measures adopted in the developed world to
ensure swift transfer of the newest technology, sometimes denied by
financial and similar constraints.

NORTH AMERICA

North America has a wide range of coastal land forms and development
patterns. Hence, its vulnerability to global warming and accelerated sea level
rise will vary from region to region. In general, the continent can be
characterized by Arctic/Pacific and Atlantic/Gulf coastal landforms. The Pacific
coast is typified by cliffed shorelines, often rocky and rugged, with relatively
few low-lying human population centers (e.g., Los Angeles, San Diego, Acapulco).
By contrast, the Atlantic and Gulf coastal plains are low, flat, and densely
populated; the outer barrier islands have become some of the most valuable real
estate in the United States, and an important source of foreign exchange for
Mexico.

Canada and the northern United States were subject to glaciation during the
past ice age. With a few exceptions, these areas tend to be more rocky, with
higher relief terrain than their southern counterparts. ThE!y are also still
experiencing isostatic rebound from the last glaciation, so that the land is
actually rising out of the sea from Oregon north, around the Arctic, and south
to Maine. Tectonic processes are also causing uplift along -the Pacific coast
between Oregon and Alaska. In areas with substantial uplift, sea level rise
will be markedly less important for the coastal ecosystems and local economy.
By contrast, the unconsolidated sediment of the Atlantic and Gulf coastal plains
are slowly subsiding about 15 cm per century, and a few areas such as Louisiana
and Galveston are subsiding several times as rapidly.

Impacts of Sea Level Rise

From an economic standpoint, Canada appears to be least vulnerable to sea
level rise owing to both its rocky coasts (Figure 25) and its low population
density. Nevertheless, St. John, Charlottetown, and a few other cities have
low-lying developed areas that might be threatened. Moreover, a number of
planned major infrastructure projects would be vulnerable to, sea level rise.

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Figure 25. Mouth of Belle Isle Straits on the Atlantic coast of Newfoundland
(Canada).

By contrast, 2.8 million Mexicans live within a few meters of sea level, and
many beach resorts would be extremely vulnerable. Although the United States
could lose the most land of the three nations -- about 20,000 square kilometers
-- such a loss would be small compared to the total land area of the country.
In both Mexico and the United States, the threat to recreational beach resorts
would be particularly great.

From an environmental standpoint, the greatest threat from sea level rise
appears to be the loss of coastal wetlands in Mexico and the United States. A
one-meter rise would inundate over half of the U.S. coastal wetlands; the low
tidal range in the Gulf of Mexico suggests that Mexico's wetlands would be at
least as vulnerable as those of the United States. Particularly vulnerable
would be the Mississippi Delta in the United States and the Grihalva Delta in
Mexico. The larger tidal ranges and relative scarcity of wetlands in Canada
suggest that this nation Would have less of a problem.

Adaptive Responses

Potential responses include structural solutions, such as dikes; soft
solutions, such as beach nourishment; and nonstructural measures, such as
bulkhead prohibitions, long-term leases, and requirements that structures be set
back from the shore. In general, structural and soft solutions can be deferred
until sea level rise is more firmly established and closer at hand. (Because
the problems are already occurring in Louisiana owing to subsidence, structural
solutions are being actively pursued even today.) By contrast, planning
measures require long lead times commensurate with the lifetimes of coastal
development. Although houses may have useful lifetimes of 30-50 years, planning
requires a longer time horizon because roads and other infrastructure channel
development for centuries.

A major theme throughout this conference has been that countries with the
greatest vulnerability to sea level rise are also the least able to respond.
This principle applies in North America, where millions of people subsist on
low-lying, erodible coastal plains near the water's edge and lack the
institutional and financial means to erect shore protection structures or to
relocate inland. The present level of protection in urban areas is barely
sufficient, as evidenced by the Hurricane Gilbert in 1988, which caused major
destruction in Mexico.

Preliminary assessments in the United States indicate that the cost to
protect the most densely developed 15% of the land threatened by sea level. rise
could total approximately $100 billion. By contrast, the only study of Canada
suggests that the cost of rebuilding coastal infrastructure would be only $3-4
billion; moreover, the net cost of sea level rise would be much less because
adjustments could be incorporated in the renovations that would take place
anyway. Although no assessments have been conducted for Mexico, the
similarities between its coasts and those of the southern United States suggest
that if structural solutions were used to protect developed areas, the cost
would be high.

Barriers to Implementing Response Strategies

Adaptive strategies would face many barriers. In Mexico and some parts of
the United States and Canada, the necessary financial resources simply would not
be available. In the United States, structural protection measures could
eventually result in the loss of most wetland shores, with consequent impacts
on coastal fisheries. Cultural problems must be considered as well. For
example, the highly developed Long Beach Island in New Jersey could probably
afford a dike, and the environmental consequences would be small if the
undeveloped portion were left outside the dike; but the loss of beaches and
waterfront views may not be acceptable to the public. Current legal constraints
make it difficult to abandon areas for the sake of wetland protection without
compensation, unless a plan to do so is put in place decades before an
abandonment is necessary.

Moreover, when one gets into the details of necessary responses, one begins
to see that our understanding of the implications of response options is
superficial at best. The feasibility of raising land, for eXample, depends in
part on the availability of inexpensive fill material, which in turn may depend
on shipping costs. But climate change may alter these costs, particularly if
sea level rise reduces clearance under bridges or m6re frequent droughts
diminish the flow in rivers.

Perhaps the most important barrier to implementing anticipatory strategies
is the lack of public awareness, which is the product of educational, social,
and cultural backgrounds. However, it may also be the most important problem
that can be theoretically dealt with by existing institutions. Most people do
not think about underlying processes (e.g., the gradual rise in sea level).
Instead, they respond only to events (e.g., catastrophic damage and loss of life
caused by a hurricane). Tragedies are blamed on the flukes of nature, and
people view themselves as victims of bad luck. Nevertheless, in the United
States there is a growing awareness among public officials and the general
public of the hazards of flooding, the importance of coastal wetlands, and the
risks due to sea level rise; in the last three years, many agencies have begun
to incorporate sea level rise in their coastal management policies. Mexico and
Canada have only begun to undertake impact assessments; neither has yet
implemented measures as a direct response to accelerated sea level rise.

Vulnerability is obvious from even a casual inspection of the present
situation, not to mention the continuing urbanization along the U.S. coasts and
the population explosion in Mexico. The picture looks bleak without even a hint
of a rainbow within the darkened clouds. Scant and incomplete as our data are
now, it is apparent that there is already trouble at the water's edge, which
will only be exacerbated by accelerated sea level rise.

CONCLUSIONS AND RECOMMENDATIONS

In many parts of the world, as a result of population growth and economic
development, the natural function of coastal areas and resources is being
degraded and impaired. These problems will be aggravated and compounded by
future sea level rise and other effects of global climlite change unless

appropriate response strategies are adopted. With a view toward sustainable
development, the current status of coastal areas and resources is a matter of
national and international concern, and care must be taken to avoid additional
adverse impacts.

Although coastal zone management is a national responsibility,
international cooperation among nations with shared concerns can improve the
management of coastal resources in general and can facilitate adaptive responses
to climate change in particular. International cooperation is particularly
valuable in the collection and use of information on available response options
and their implications.

Existing international organizations, such as the UNEP and its Regional
Seas Programme, should be used to identify and evaluate solutions for present
and future problems in the management of coastal areas and resources, especially
for developing countries.

While uncertainty remains regarding the magnitude and timing of accelerated
sea level rise, current information from the IPCC Working Group I suggests that
a rise in sea level of 25 to 40 cm is possible by the middle of the next
century. Even if measures are adopted to limit emissions of greenhouse gases,
sea level is expected to continue rising for some time. Thus, coastal states
must consider how to adapt.

The highest priority tasks include:

1. Identifying coastal areas, populations, and resources at risk from
sea level rise, and undertaking topographic mapping with improved
vertical resolution.

2. Developing global and regional systems to research, monitor, and
predict sea level rise and its consequences.

3. Educating the public, to develop awareness of the risks to coastal
resources from both existing activities and future sea level rise,
and also to keep these critical issues in the forefront of public
and government attention.

4. Elaborating or amending national policies and legal structures for
integrated management of coastal and related areas and resources.

5. Ensuring that new coastal projects do not place further stress on
coastal areas and resources.

6. Enhancing research programs and encouraging collection and
dissemination of all relevant data and information to improve our
understanding of (a) the status and trends of the physical systems
at the national and cross-boundary level (geomorphological,
hydrological, hydraulic, etc.); (b) the economic implications of
resource allocation, planning, analysis, and implementation at both
the national and cross-boundary levels; (c) the environmental and
ecological implications involved in effective coastal zone

management; and (d) the social and cultural implications and
constraints facing adaptive strategies. This research will help us
to develop the necessary legal, planning, and institutional
capabilities for integrated management of coastal resources and
related areas.

7. Providing technical and financial assistance to developing countries
for research and management of coastal areas and resources.

8. Using country-specific studies to evaluate available adaptive
options.

9. Adopting a framework convention on climate change to facilitate
cooperative efforts to limit and/or adapt to global climate change.

PROBLEM IDENTIFICATION

CAUSES OF SEA LEVEL RISE

PAST TRENDS IN SEA LEVEL

The worldwide average sea level depends primarily on (1) the shape and size
of ocean basins, (2) the amount of water in the oceans, and (3) the average
density of seawater. The latter two factors are influenced by climate, but the
first is not. Subsidence and emergence due to natural factors such as isostatic
and tectonic adjustments of the land surface, as well as human-induced factors
such as oil and water extraction, can cause trends in "relative sea level" at
particular locations to differ from trends in "global sea level."

Hays and Pitman (1973) analyzed fossil records and concluded that over the
last 100 million years, changes in mid-ocean ridge systems have caused sea level
to rise and fall over 300 meters. However, Clark et al. (1978) have pointed out
that these changes have accounted for sea level changes of less than one
millimeter per century. No published study has indicated that this determinant
of sea level is likely to have a significant impact in the next century.

The impact of climate on sea level has been more significant over relatively
short periods of time. Geologists generally recognize that during ice ages, the
glaciation of substantial portions of the Northern Hemisphere has removed enough
water from the oceans to lower sea level 100 meters below present levels during
the last (18,000 years ago) and previous ice ages (Donn et al., 1962; Kennett,
1982; 01dale, 1985).

Although the glaciers that once covered much of the Northern Hemisphere
have retreated, the world's remaining ice cover contains enough water to raise
sea level over 75 meters (Hollin and Barry, 1979). Hollin and Barry (1979)
and Flint (1971) estimate that existing alpine glaciers contain enough water to
raise sea level 30 or 60 centimeters, respectively. The Greenland and West
Antarctic ice sheets each contain enough water to raise sea level about 7 meters,
while East Antarctica has enough ice to raise sea level over 60 meters. There
is no evidence that either the Greenland or East Antarctic ice sheet has
completely disintegrated in the last two mill ion years. However, it is generally

1 Editor's note: Workgroup I has not been authorized to provide a paper
to the proceedings. For completeness, we reprint the following, adapted from
Effects of Changes in Stratospheric Ozone and Global Climate, published by UNEP
and EPA.

Problem Identification

recognized that sea level was about seven meters higher than today during the
last interglacial, which was 1-20C warmer (Mercer, 1970; Hollill, 1972). Because
the West Antarctic ice sheet is marine-based and thought by some to be
vulnerable to climatic warming, attention has focused on this source for the
higher sea level. Mercer (1968) found that lake sediments and other evidence
suggested that summer temperatures in Antarctica have been 7 to 10'C higher than
today at some point in the last two million years, probably the last interglacial
125,000 years ago, and that such temperatures could have caused a disintegration
of the West Antarctic ice sheet. However, others are not certain that marine-
based glaciers are more vulnerable to climate change than land-based glaciers;
Robin (1986) suggests that the higher sea level during the last interglacial
period may have resulted from changes in the East Antarctic ice sheet.

Tidal gauges have been available to measure the change in relative sea
level at particular locations over the last century. Studies combining these
measurements to estimate global trends have concluded that sea level has risen
1.0 to 2.5 millimeters per year during the last century (Peltier and Tushingham,
1989; Barnett, 1984; Gornitz et al., 1982; Fairbridge and Krebs, 1962). Barnett
(1984) found that the rate of sea level rise over the last 50 years had been
about 2.0 mm/yr, whereas in the previous 50 years there had been little change;
however, the acceleration in the rate of sea level rise was not statistically
significant. Emery and Aubrey (1985) have accounted for estimated land surface
movements in their analyses of tidal gauge records in Northern Europe and
western North America, and have found an acceleration in the rate of sea level
rise over the last century.

Several researchers have sought to explain the source of current trends in
sea level. Barnett (1984) and Gornitz et al . (1982) estimate that thermal
expansion of the upper layers of the oceans resulting from the observed global
warming of 0.40C in the last century could be responsible for a rise of 0.4 to
0. 5 mm/yr. Roemmich and Wunsch (1984) examined temperature and salinity
measurements at Bermuda and concluded that the VC isotherm had migrated 100
meters downward, and that the resulting expansion of ocean water could be
responsible for some or all of the observed rise in relative sea level. Roemmich
(1985) showed that the warming trend 700 meters below the surface was
statistically significant. Meier (1984) estimates that retreat of alpine
glaciers and small icecaps could be currently contributing between 0.2 and 0.72
mm/yr to sea level. The National Academy of Sciences Polar Research Board (Meier
et al., 1985) concluded that existing information is insufficient to determine
whether the impacts of Greenland and Antarctica are positive 'Dr zero. Although
the estimated global warming of the last century appears to be at least partly
responsible for the last century's rise in sea level, studies have not yet
demonstrated that global warming is responsible for acceleration in the rate
of sea level rise.

The Greenhouse Effect

Although global temperatures and sea level have been fairly stable in recent
centuries, the future may be very different. Increasing concentrations of carbon
dioxide, methane, chlorofluorocarbons, and other gases released by human

activities could heat the Earth to temperatures warmer than at any time in the
last two million years and thereby accelerate the rate of sea level rise.

A planet's temperature is determined primarily by the amount of sunlight
it receives, the amount of sunlight it reflects, and the extent to which its
atmosphere retains heat. When sunlight strikes the Earth, it warms the surface,
which radiates the heat as infrared radiation. However, water vapor, carbon
dioxide, and a few other gases found naturally in the atmosphere absorb some
of the energy instead of allowing it to pass undeterred through the atmosphere
to space. Because the atmosphere traps heat and warms the Earth in a manner
somewhat analogous to the glass panels of a greenhouse, this phenomenon is
generally known as the greenhouse effect; the relevant gases are known as
greenhouse gases. Without theogreenhouse effect of the gases that occur
naturally, the Earth would be 33 C (600F) colder than it is currently (Hansen
et al., 1984).

Since the industrial revolution, the combustion of fossil fuels,
deforestation, and cement manufacture have released enough C02 into the
atmosphere to raise the atmospheric concentration of C02 by 20 percent; the
concentration has increased 10 percent since 1958 (Keeling, 1983). Carbon cycle
modelers and energy economists generally expect the concentration of C02 to
increase 50 percent by 2050 and to double by 2075. Recently, the concentrations
of chlorofluorocarbons, methane, nitrous oxide, carbon tetrachloride, ozone,
and dozens of other trace gases that also absorb infrared radiation have also
been increasing (Lacis et al., 1981). Ramanathan et al. (1985) estimated that
the combined impacts of these other gases are likely to be as great as C021
which implies that by 2050, the atmospheric concentration of greenhouse gases
will be equivalent to a doubling of carbon dioxide.

All projections of future concentrations have been based on the assumption
that current trends will continue and that governments will not regulate
emissions of greenhouse gases. However, in the fall of 1987, most of the
industrial nations agreed to cut emissions of the chlorofluorocarbons by 50
percent over the following decade. Moreover, the United Nations has created an
Intergovernmental Panel on Climate Change to develop strategies to reduce
emissions of greenhouse gases in general. Nevertheless, curtailing emissions
will be difficult. There is considerable doubt regarding the global warming
that would result from a doubling of carbon dioxide. There is general agreement
that the average temperature would rise 1.2*C if nothing else changed. However,
warmer temperatures would allow the atmosphere to retain more water vapor, which
is also a greenhouse gas, increasing the warming. A retreat of ice cover would
also amplify the warmi 'ng, while possible changes in cloud cover could increase
or decrease the warming. Two reports by the National Academy of Sciences have
developed a consensus estimate that the average warming will be 1.5 to 4.50C,
and that the polar areas will warm two to three times as much.

Impact of Future Global Warming on Sea Level

Concern about a substantial rise in sea level as a result of the projected
global warming stemmed originally from Mercer (1968), who suggested that the
Ross and Filchner-Ronne ice shelves might disintegrate, causing a deglaciation

Problem Identification

of the West Antarctic ice sheet and a resulting 6- to 7-meter rise in sea level,
possibly over a period as short as 40 years.

Subsequent investigations have concluded that such a rapid rise is unlikely.
Hughes (1983) and Bentley (1983) estimated that such a disintegration would take
at least 200 or 500 years, respectively. Other researchers have estimated that
this process would take considerably longer (Fastook, 1985; Lingle, 1985).

Researchers have turned their attention to the magnitude of sea level rise
that might occur in the next century. The best understood factors are the thermal
expansion of ocean water and the melting of alpine glaciers. In the National
Academy of Sciences (NAS) report "Changing Climate," Revelle (1983) used the
model of Cess and Goldenberg (1981) to estimate temperature increases at various
depths and latitudes resulting from a 4.20C warming by 2050-2060. While noting
that his assumed time constant of 33 years probably resulted in a conservatively
low estimate, he estimated that thermal expansion would result in an expansion
of the upper ocean sufficient to raise sea level 30 cm.

Using a model of the oceans developed by Lacis et al. (1981), Hoffman et
al. (1986) examined a variety of possible scenarios of future emissions of
greenhouse gases and global warming. They estimated that a warming of between
1 and 2.60C could result in thermal expansion contributing between 12 and 26 cm
by 2050. They also estimated that a global warming of 2.3 to 7.00C by 2100 would
result in thermal expansion of 28 to 83 cm by that year.

Revelle (1983) suggested that while he could not estimate the future
contribution of alpine glaciers to sea level rise, a contribution of 12 cm
through 2080 would be reasonable. Meier (1984) used glacier balance and volume
change data for 25 glaciers where the available record exceeded 50 years to
estimate the relationship between historic temperature increases and the
resulting negative mass balances of the.glaciers. He estimated that a 28-mm
rise had resulted from a warming of 0.5 C, and concluded that a 1.5 to 4.50C
warming would result in a rise of 8 to 25 cm in the next centUry. Using these
results, the NAS Polar Board concluded that the contribution of glaciers and
small ice caps through 2100 is likely to be 10 to 30 cm (Meier et al., 1985).
They noted that the gradual depletion of remaining ice cover might reduce the
contribution of sea level rise somewhat. However, the contribution might also
be greater, given that the historic rise took place over a 60-year period, while
the forecast period is over 100 years. Using Meier's estimated relationship
between global warming and the alpine contribution, Hoffman et al. (1986)
estimated alpine contributions through 2100 at 12 to 38 cm for a global warming
of 2.3 to 7.OOC.

The first published estimate of the contribution of Greenland to future sea
level rise was Revelle's (1983) estimate of 12 cm through the year 2080. Using
estimates by Ambach (1980 and 1985) that the equilibrium line (between snowfall
accumulation and melting) rises 100 meters for each 0.60C rise in air
temperatures, he concluded that the projected 60C warming in Greenland would be
likely to raise the equilibrium line 1,000 meters. He estimated.that such a
change in the equilibrium line would result in a 12-cm contribution to sea level
rise for the next century.

The NAS Polar Board (Meier et al., 1985) noted that Greenland is a
"significant potential contributor of meltwater." They found that a 1,000-meter
rise in the equilibrium line would result in a contribution of 30 cm through
2100. However, because Ambach (1985) found the relationship between the
equilibrium line and temperature to be 77 meters per degree Celsius, the panel
concluded that a 500-meter shift in the equilibrium line would be more likely.
Based on the assumption that Greenland will warm 6.50C by 2050 and that
temperatures will remain constant thereafter, the panel estimated that such a
change would contribute about 10 cm to sea level through 2100, but also noted
that "for an extreme but highly unlikely case, with the equilibrium line raised
1000 meters, the total rise would be 26 cm."

The potential impact of a global warming on Antarctica in the next century
is the least certain of all the factors by which a global warming might
contribute to sea level rise. Meltwater from East Antarctica might make a
significant contribution by the year 2100, but no one has estimated the likely
contribution. Several studies have examined "deglaciation," which also includes
the contribution of ice sliding into the oceans. Bentley (1983) examined the
processes by which a deglaciation of West Antarctica might occur. The first step
in the process would be accelerated melting of the undersides of the Ross and
Filchner-Ronne ice shelves as a result of warmer water circulating underneath
them. The thinning of these ice shelves could cause them to become unpinned and
would cause their grounding lines to retreat. Revelle (1983) concluded that the
available literature suggests that the ice shelves might disappear in 100 years,
after which time the Antarctic ice streams would flow directly into the oceans,
without the back pressure of the ice shelves. He suggested that this process
would take 200 to 500 years.

Although a West Antarctic deglaciation would occur over a period of
centuries, it is possible that an irreversible deglaciation could commence before
2050. If the ice shelves thinned more than about one meter per year, Thomas et
al. (1979) suggested that the ice would move into the sea at a sufficient speed
that even a cooling back to the temperatures of today would not be sufficient
to result in a reformation of the ice shelf.

To estimate the likely antarctic contribution for the next century, Thomas
(1985) developed four scenarios of the impact of a VC global warming by 2050,
estimating that a 28-cm rise would be most likely, but that a rise of I to 2.2
meters would be possible under certain circumstances. The NAS Pol ar Board
(Meier et al., 1985) evaluated the Thomas study and papers by Lingle (1985) and
Fastook (1985). Although Lingle estimated that the contribution of West
Antarctica through 2100 would be 3 to 5 cm, he did not evaluate East Antarctica,
while Fastook made no estimate for the year 2100. Thus, the panel concluded
that "imposing reasonable limits" on the model of Thomas yields a range of 20
to 80 cm by 2100 for the antarctic contribution. However, they also noted
several factors that would reduce the amount of ice discharged into the sea:
the removal of the warmest ice from the ice shelves, the retreat of grounding
lines, and increased lateral shear stress. They also concluded that increased
precipitation over Antarctica Rigt increase the size of the polar ice sheets
there. Thus, the panel concluded that Antarctica could cause a rise in sea
level up to I meter, or a drop of 10 cm, with a rise between 0 and 30 cm most
likely.

Problem Identification

Using a range of estimates for future concentrations of greenhouse gases,
the climate's sensitivity to such increases, oceanic heat uptake, and the
behavior of glaciers, Hoffman et al., (1983) estimated that the rise would be
between 56 and 345 cm, with a rise of 144 to 217 cm most likely; however, they
did not examine the impact of deliberate attempts by society to curtail
emissions. Revelle (1983) estimated that the rise was likely to be 70 cm,
ignoring the impact of a global warming on Antarctica; he also noted that the
latter contribution was likely to be 1 to 2 m/century after 2050, but declined
to add that to his estimate. The NAS Polar Board (Meier et al ., 1985) projected
that the contribution of glaciers would be sufficient to raise sea level 20 to
160 cm, with a rise of "several tenths of a meter" most likely. Thus, if one
extrapolates the earlier NAS estimate of thermal expansion through the year
2100, the 1985 NAS report implies a rise between 50 and 200 cm. The estimates
from Hoffman et al . (1986) for the year 2100 (57 to 368 cm) were similar to
those by Hoffman et al. (1983). However, for the year 2025, they lowered their
estimate from 26-39 cm to 10-21 cm. More recently, IPCC Work Group 1 has
tentatively concluded that a rise of 20-50 cm by 2050, and 50-100 cm by 2100,
seems likely.

Future Trends in Local Sea Level

Although most attention has focused on projections of global sea level,
impacts on particular areas would depend on local relative sea level. Local
subsidence and emergence are caused by a variety of factors. Re *bound from the
retreat of glaciers after the last ice age has resulted in the uplift of
northern Canada, New England, and parts of Scandinavia, while emergence in Alaska
is due more to tectonic adjustments. The uplift in polar latitudes has resulted
in subsidence in other areas, notably the U.S. Atlantic and gulf coasts.
Groundwater pumping has caused rapid subsidence around Houston, Texas, Taipei,
Taiwan, and Bangkok, Thailand, among other areas (Leatherman, 1983). River
deltas and other newly created land subside as the unconsolidated materials
compact. Although subsidence and emergence trends may change in the future,
particularly where anthropogenic causes are curtailed, no one has linked these
causes to future climate change in the next century.

However, the removal of ice from Greenland and Antarctica would immediately
alter gravitational fields and eventually deform the ocean floor. For example,
the ice on Greenland exerts a gravitational pull on the ocean's water; if the
Greenland ice sheet melts and the water is spread throughout the globe, that
gravitational attraction will diminish and could thereby cause sea level to drop
along the coast of Greenland and nearby areas such as Iceland and Baffin Island.
Eventually, Greenland would also rebound upward, just as northern areas covered
by glaciers during the last ice age are currently rebounding'. Clark and Lingle
(1977) have calculated the impact of a uniform 1-meter contribution from West
Antarctica. They concluded that relative sea level at Hawaii would rise 125
cm, and that along much of the U.S. Atlantic and gulf coasts the rise would be
15 cm. On the other hand, sea level would drop.at Cape Horn by close to 10 cm,
and the rise along the southern half of the Argentine and Chilean coasts would
be less than 75 cm.

Other contributors to local sea level that might change as a result of a
global warming include currents, winds, and freshwater flow into estuaries.
None of these impacts, however, has been estimated.

CONCLUSION

There is a growing body of evidence that sea level rise will accelerate in
the coming decades. Although recent assessments have generally suggested that
the rise will not be as great as people thought possible in the early 1980s,
they have further increased the certainty that at least some rise will take
place. Accordingly, coastal nations throughout the world need to begin
considering the effects and possible responses.

BIBLIOGRAPHY

Ambach, W. 1985. Climatic shift of the equilibrium line -- Kuhn's concept
applied to the Greenland ice cap. Annals of Glaciology 6:76-78.

Ambach, W. 1980. Increased C02 concentration in the atmosphere and climate
change: potential effects on the Greenland ice sheet. Wetter und Leben 32:135-
142, Vienna. (Available as Lawrence Livermore National Laboratory Report
UCRL-TRANS-11767, April 1982.)

Barnett, T.P. 1984. The estimation of global sea level change: a problem of
uniqueness. Journal of Geophysical Research 89(C5):7980-7988.

Bentley, C.R. 1983. West Antarctic ice sheet: diagnosis and prognosis. In:
Proceedings: Carbon Dioxide Research Conference: Carbon Dioxide, Science, and
Consensus. Conference 820970. Washington, DC: U.S. Department of Energy.

Cess, R.D., and S.D. Goldenberg. 1981. The effect of ocean heat capacity upon
global warming due to increasing atmospheric carbon dioxide. Journal of
Geophysical Research 86:498-502.

Clark, J.A., W.E. Farrell, and W.R. Peltier. 1978. Global changes in
postgl aci al sea I evel : a numeri cal cal cul ati on. Quarternary Research 9:265-87.

Clark, J.A., and C.S. Lingel. 1977. Future sea-level changes due to west
Antarctic ice sheet fluctuations. Nature 269(5625):206-209.

Donn, W.L., W.R. Farrand, and M. Ewing. 1962. Pleistocene ice volumes and
sea-level lowering. Journal of Geology 70:206-214.

Emery, K.O., and D.G. Aubrey. 1985. Glacial rebound and relative sea levels
in Europe from tide-gauge records. Tectonophysics 120:239-255.

Fairbridge, R.W., and W.S. Krebs, Jr. 1962. Sea level and the southern
oscillation. Geophysical Journal 6:532-545.

Prob7em Identification

Fastook, J.L. 1985. Ice shelves and ice streams: three modeling experiments.
In: Glaciers, ice sheets, and sea level. Meier, M.F. et al., eds. Washington,
DC: National Academy Press.

Flint, R.F. 1971. Glacial and Quarternary Geology. New York: John Wiley and
Sons.

Gornitz, V., S. Lebedeff, and J. Hansen. 1982. Global sea level trend in the
past century. Science 215:1611-14

Hansen, J.E., A. Lacis, D. Rind, and G. Russell. 1984. Climate sensitivity to
increasing greenhouse gases. In: Greenhouse Effect and Sea Level Rise: A
Challenge for this Generation. M.C. Barth and J.G. Titus, eds. New York:
Van Nostrand Reinhold.

Hays, J.D., and W.C. Pitman 111. 1973. Lithsopheric plate motion, sea level
changes, and climatic and ecological consequences. Nature 246:18-22.

Hoffman, J.S., D. Keyes, and J.G. Titus. 1983. Projecting future sea level
rise. Washington, DC: Government Printing Office.

Hoffman, J.S., J. Wells, and J.G. Titus. 1986. Future global warming and sea
level rise. In: Sigbjarnarson, G., ed. Iceland Coastal and River Symposium
Reykjavik: National Energy Authority.

Hollin, J.T., and R.G. Barry. 1979. Empirical and theoretical evidence
concerning the response of the earth's ice and snow cover to a global temperature
increase. Environment International 2:437-444.

Hughes, T. 1983. The stability of the west Antarctic ice sheet: what has
happened and what will happen. In: Proceedings: Carbon Dioxide Research
Conference: Carbon Dioxide, Science, and Consensus. Conference 820970.
Washington, DC: Department of Energy.

Keeling, C.D. 1983. The global carbon cycle: what we know and could know from
atmospheric, biospheric, and oceanic observations. In: Institute for Energy
Analysis. Proceedings: Carbon Dioxide Research Conference: Carbon Dioxide,
Science and Consensus. DOE CONF-820970, U.S. DOE, Washington, DC 11.3-11.62.

Kennett, J. 1982. Marine Geology, Prentiss-Hall. Englewood Cliffs, New Jersey:
Prentess-Hall.

Lacis, A. et al . 1981. Greenhouse effect of trace gases, 1970-1980.
Geophysical Research Letters 81(10):1035-1038.

Leatherman, S.P. 1983. Coastal hazards mapping on barrier islands. Proceedings
of National Symposium on Preventing Coastal Flood Disasters, Natural Hazards.
Res. and Appl. Spec. Publ. #7, Boulder, Colorado, p. 165-75.

Lingle, C.S. 1985. A model of a polar ice stream and future sea level rise
due to possible drastic of the west Antarctic ice sheet. In: Glaciers, ice
sheets, and sea level. Meier, M.F. et al., eds. Washington, DC: National
Academy Press.

Meier, M.F. et al . 1985. Glaciers, ice sheets, and sea level . Washington, DC:
National Academy Press.

Meier, M.F. 1984. Contribution of small glaciers to global sea level . Science
226(4681):1418-1421.

Mercer, J.H. 1970. Antarctic ice and interglacial high sea levels. Science
168:1605-6.

Mercer, J.H. 1968. Antarctic ice and Sangamon sea level. Geological Society
of America Bulletin 79:471.

National Academy of Sciences. 1979. C02 and Climate: A Scientific Assessment.
Washington, DC: National Academy Press.

National Academy of Sciences. 1982. CO, and Climate: A Second Assessment.
Washington, DC: National Academy Press.

Oldale, R. 1985. Late quarternary sea level history of New England: a review
of published sea level data. Northeastern Geology 7:192-200.

Peltier and Tushingham. 1989. Global sea level rise and the greenhouse effect:
might they be connected? Science 244:806.

Ramanathan, V., R.J. Cicerone, H.B. Singh, and J.T. Kiehl. 1985. Trace gas
trends and their potential role in climate change. Journal of Geophysical
Research 90:5547-66.

Revelle, R. 1983. Probable future changes in sea level resulting from increased
atmospheric carbon dioxide. In: Changing Climate. Washington, DC: National
Academy Press.

Robin, G. de Q. 1986. Changing sea level. In: Greenhouse Effect, Climatic
Change, and Ecosystems. New York: John Wiley & Sons.

Roemmich, D. 1985. Sea level and thermal variability of the ocean. In:
Glaciers, Ice Sheets, and Sea Level. Washington, DC: National Academy Press.

Roemmich, D., and C. Wunsch. 1984. Apparent changes in the climatic state of
the deep north Atlantic Ocean. Nature 207:447-450.

Thomas, R.H. 1985. Responses of the polar ice sheets to climatic warming. In:
Glaciers, ice sheets, and sea level. Meier, M.F. et al., eds. Washington, DC:
National Academy Press.

Thomas, R.H. , T.J.O. Sanderson, and K.E. Rose. 1979. Effect of climatic warming
on the west Antarctic ice sheet. Nature 227:355-358.

AN OVERVIEW OF THE EFFECTS OF GLOBAL WARMING
ON THE COAST

JAMES G. TITUS
Office of Policy Analysis
U.S. Environmental Protection Agency
Washington, DC 20460

Global warming could raise sea level several tens of centimeters in the next
fifty years, about one meter in the next century, and several meters in the next
few centuries by expanding ocean water, by melting mountain glaciers, and by
causing ice sheets to melt or slide into the oceans. Such a rise would inundate
deltas, coral atoll islands, and other coastal lowlands; erode beaches;
exacerbate coastal flooding; and threaten water quality in estuaries and
aquifers.

Most nations have sufficient high ground to permit a gradual adaptation, but
not without substantial investments in infrastructure and the loss of important
ecosystems. About 50 to 80 percent of coastal wetlands could be lost, with river
deltas particularly important. In a few cases, a rise in sea level would
threaten an entire nation. The Republic of Maldives and other coral atoll
nations are mostly less than two meters above sea level. Bangladesh, already
overcrowded, would lose 20 percent of its land if sea level rose one meter.
Although most of Egypt is well above sea level, its only inhabited area, the Nile
Delta, is not.

This chapter examines the consequences of future sea level rise. After
briefly summarizing the impacts of global warming on sea level, we describe the
physical effects of sea level rise, their interactions with current activities,
and the implications for particular nations.

PAST AND FUTURE SEA LEVEL RISE

Ocean levels have always fluctuated with changes in global temperatures.
During the ice ages, when the Earth was 50C colder than today, much of the
oceanis water was frozen in glaciers and sea level was often more than 100 meters
below its current level (Bonn et al., 1962; Kennett, 1982; Oldale, 1985).
Conversely, during the last interglacial period (120,000 years ago) when the
average temperature was 1-20C warmer than today, sea level was about 6 meters
higher than today (Mercer, 1968).

Problem Identification

When considering shorter periods of time, worldwide sea level rise must be
distinguished from relative sea level rise. Although global warming would alter
worldwide sea level, the rate of sea level rise relative to a particular coast
has more practical importance and is all that monitoring stations can measure.
Because most coasts are sinking (although a few are rising), relative sea level
rise varies from more than one meter per century, in some areas with high rates
of groundwater or mineral extraction, to a drop in extreme northern latitudes.
Global sea level trends have been generally estimated by combining trends at
,tidal stations around the world. Studies combining these measurements suggest
that during the last century, worldwide sea level has risen 10 to 25 centimeters
(Fairbridge and Krebs, 1962; Barnett, 1984; Peltier and Tushingham, 1989).

Future global warming could raise sea level by expanding ocean water, by
melting mountain glaciers, and eventually, by causing polar ice sheets in
Greenland and Antarctica to melt or slide into the oceans. Hughes (1983) and
Bentley (1983) suggested that over a period of 200-500 years, it might be
possible for global warming to induce a complete disintegration of the West
Antarctic ice sheet, which would raise sea level about 6 meters. Most recent
assessments, however, have focused on the rise that could occur in the next
century. As Figure 1 shows, the estimates are generally between 50 and 200
centimeters, with recent estimates being at the low end of the range.

All assessments of future sea level rise have emphasized that much of the
data necessary for accurate estimates are unavailable. As a result, studies of
the possible impacts generally have used a range of scenari,DS. Nevertheless,
for convenience of exposition, it is often necessary to refer to only a single
estimate. For illustrative purposes, we follow the conventiOn of referring to
a one-meter rise in sea level.

PHYSICAL EFFECTS OF SEA LEVEL RISE

We now examine the impact of sea level rise assuming that society's impact
on the coastal environment does not change. We first summarize the most
important processes, then discuss a few examples of the interaction of these
physical impacts with human activities.

Processes

A rise in sea level would (1) inundate wetlands and lowlands, (2) erode
shorelines, (3) exacerbate coastal flooding, (4) increase, the salinity of
estuaries and aquifers and otherwise impair water quality, (5) alter tidal ranges
in rivers and bays, (6) change the locations where rivers deposit sediment, (7)
increase the heights of waves, and (8) decrease the amount of light reaching the
bottoms. Previous assessments have mostly focused on the first four factors
(e.g., Barth and Titus, 1984; Dean et al., 1987).

Titus

4.0 -

a Hoffman (1983) High

3.0--

uj
> Glacier Volume Estimate of Polar 0 Hoffman (.1983) Mid-High
1-- 2.0- Board Augmented With Thermal
C Expansion Estimates by NRC 9 Meier (1985 ) High
(1983)

U) 9 WMO (1986) High
Hoffman (1983) Mid-Low
LU

oil
-i

Ui 1.0

� Revelle (11983)

� Hoffman (1983) Low
Past Century 0 Meier (1985 )Low*
i WMO (1986) Low
: 0.12 m Rls I
0.0 2000 2050 2100
YEAR

Figure 1. Estimates of future sea level rise.

Inundation

"Inundation," the most obvious impact of sea level rise, refers both to the
conversion of dryland to wetlands and to the conversion of wetlands to open
* iWMO (1986.

water. Consider a bay with a tide range of one meter and a parcel of dryland
that is currently 75 centimeters above sea level, that is, 25 centimeters above
high water. If the sea rose 25 centimeters overnight, the land would be flooded
at high tide and hence would convert to wetland, while a 125-cm rise would
convert it to open water.

Problem Identification

Nature requires coastal wetlands and the dryland found on coral atolls,
barri er i sl ands, and ri ver del tas to be just above sea I evel . If sea 1 evel ri ses
slowly, as it has for the last several thousand years, these lands can keep pace
with the sea: Wetlands collect sediment and produce peat that enable them to
stay just above sea level; atoll islands are sustained by sand produced by the
coral reefs; barrier islands migrate landward; and deltas are built up by the
sediment washed down major rivers. If sea level rise accelerates, however, at
least some of these lands will be lost.

A one-meter rise in sea level would inundate 17 percent of Bangladesh (Ali
and Huq, 1989; see Figure 2), and a two-meter rise would inundate the capital and

BANGLADESH

NS-V
/J

0 2D 40 W M IOMn

Figure 2. Impact of 3-m and 1-m relative sea level rise on Bangladesh. Because
of current subsidence, a smaller rise in global sea level could cause this effect
(Bangladesh Center for Advanced Studies).

Titus

over half the populated islands of the atoll Republic of Maldives. Although the
land within a few meters of sea level accounts for a relatively small fraction
of the area of most nations, populations are often concentrated in the low areas
owing to the fertility of coastal lowlands, the historic reliance on water
transportation, and more recently, the popularity of living by the sea.
Shanghai and Lagos -- the largest cities of China and Nigeria -- are less than
two meters above sea level, as is 20 percent of the population and farmland of
Egypt (Broadus et al., 1986).

Coastal plains in general would be less vulnerable than atolls, deltas, and
barrier islands, because they typically range in elevation from zero to 70 meters
above sea level. Nevertheless, because they account for much more land and do
not keep pace with sea level, they would probably account for the majority of
dryland lost to inundation, particularly for a large rise in sea level. A recent
study of the United States illustrates the situation: If sea level rose 50 cm,
the Mississippi Delta alone would account for 35 percent of the nation's lost
dryland; but because a 50-cm rise (along with current subsidence) would inundate
most it, the delta would account for only 10 percent of U.S. dryland lost if sea
level rose 2 meters (U.S. EPA, 1989).

Unlike most dryland, all coastal wetlands can keep pace with a slow rate of
sea level rise. As Figure 3 shows, this ability has enabled the area of wetlands

5000 YEARS AGO TODAY

SEA LEVEL CURRENT
SEA LEVEL
SEDIMENTATION AND - - - - - - - PAST
PEAT FORMATION SEA LEVEL

FUTURE

COMPLETE WETLAND LOSS WHERE HOUSE IS PROTECTED
SUBSTANTIAL WETLAND LOSS WHERE THERE IS VACANT UPLAND IN RESPONSE TO RISE IN SEA LEVEL

FUTURE
SEA LEVEL SEA LEVEL
FUTURE

- - - - - - - I - - CURRENT - - - - - - - - - - CURRENT
SEA LEVEL SEA LEVEL

PEAT ACCUMULATION

Figure 3. Evolution of marsh as sea rises. Coastal marshes have kept pace with
the slow rate of sea level rise that has characterized the last several thousand
years. Thus, the area of marsh has expanded over time as new lands have been
inundated. If, in the future, sea level rises faster than the ability of the
marsh to keep pace, the marsh area will contract. Construction of bulkheads to
protect economic development may prevent new marsh from forming and result in a
total loss of marsh in some areas (Titus, 1986).

Problem Identification

to increase over the last several thousand years. However, most authors have
concluded that wetlands could not keep pace with a significant acceleration in
sea level rise (Kearney and Stevenson, 1985), and thus, that the area of wetlands
converted to open water will be much greater than the area of dryland converted
to wetlands (Titus et al., 1984; Park et al., 1986; Armentano et al., 1988).
Moreover, in areas where dikes protect farmland or structures, all the wetlands
could be lost (Titus, 1986, 1988).

Because they are found below the annual high tide, the most vulnerable
wetlands would tend to be those in areas with tidal ranges of less than one
meter, such as the Mediterranean and Black Seas, the Gulf of Mexico, and
estuaries with narrow openings to the sea. The least vulnerable would be those
in areas with large tidal ranges, such as the Bay of Fundy. Although areas with
substantial sediment supplies could maintain more wetlands than those with little
sediment, the percentage loss would not necessarily be less, since these areas
currently have more wetlands.

Erosion

In many areas, the total shoreline retreat from a one-meter rise would be
much greater than suggested by the amount of land below the onE!-meter contour on
a map, because shores would also erode. While acknowledging that erosion is also
caused by many other factors, Bruun (1962) showed that as sea level rises, the
upper part of the beach is eroded and deposited just offshore in a fashion that
restores the shape of the beach profile with respect to sea level, as shown in
Figure 4; the "Bruun Rule" implies that a one-meter rise would generally cause
shores to erode 50 to 200 meters along sandy beaches, even if the visible portion
of the beach is fairly steep.

On coastal barrier islands, wave erosion may transport sand in a landward
as well as a seaward direction, a process commonly known as "overwash." By
gradually transporting it landward, overwash can enable a barrier island to rise
with sea level, in a fashion similar to rolling up a rug, as shown in Figure 5.
Leatherman (1979) suggests that barrier islands would generally erode from their
ocean sides until reaching a width of 100-200 meters, at whic@i point they would
wash over. Although barrier islands have been able to maintain themselves in
this fashion with the relatively slow historic rate of sea level rise, coastal
scientists are uncertain about the extent to which they could do so with a more
rapid rise in sea level. In the Mississippi Delta, for example, where relative
sea level has risen one meter in the last century, many barrier islands have
gradually broken up and disintegrated.

Wetlands and other muddy coasts would be even more vulnerable to erosion.
Under the Bruun formulation, erosion due to sea level rise is a self-limiting
process: a given storm can wash up sand and pebbles only sever-al hundred meters
before they settle out; the material thus remains in the beach system. By
contrast, muddy sediments can be carried great distances before settling out, and
the peat that constitutes part of wetland coasts can oxidize into carbon dioxide,
methane, and water (Reed, 1988).

Titus

. . . . . . . . . ....................
. . . . . . . . . . . . .

N. . . . . . . . . .

- - - - - - - - - - - - - -

......... .

PRE;I(FUS
SEA LEVEL

ez-

2-.-7777=

Figure 4. The Bruun Rule: (a) initial condition; (b) immediate inundation when
sea level rises; and (c) subsequent erosion due to sea level rise. A rise in sea
level immediately results in shoreline retreat due to inundation, shown in the
first two examples. However, a 1-meter rise in sea level implies that the
offshore bottom must also rise I meter. The sand required to raise the bottom
(X') can be supplied by beach nourishment. Otherwise, waves will erode the
necessary sand (X) from upper part of the beach as shown in (c) (Titus, 1986).

Initial Case

After Sea Level Rises

-----------------
Previous Sea Level

Figure 5. Overwash: natural response of undeveloped barrier islands to sea
level rise.

Prob7em Identification

The practical importance of distinguishing erosion from inundation varies
(Park et al., 1989). Along the very low deltaic coasts, erosion would merely
reclaim land for a few decades before it was inundated aryway. On barrier
islands and sandy cliffed coasts, however, where a one-meter rise would inundate
only 5-20 meters of beach, erosion would account for the majority of land lost.
Flooding

Sea level rise could increase the risk of flooding in four ways: (1) There
would be a higher base upon which storm surges would build. If sea level rises
one meter, an area flooded with 50 cm of water every 20 years would now be
flooded with 150 cm every 20 years; surges would also penetrate farther inland
(Kana et al., 1984). (2) Beaches and sand dunes currently protect many areas
from direct wave attack; by removing these protective barriers, erosion from sea
level rise would leave some areas along ocean coasts more vulnerable. (3)
Mangroves and marshes slow the inland penetration of floodwater by increasing the
friction of estuaries and by blocking the waves; losses of wetlands would thus
increase coastal flooding (Louisiana Wetland Protection Panell, 1988). finally,
(4) Sea level rise could also increase flooding from rainstorms and river surges
as a result of decreased drainage (Titus et al., 1987).

The higher base for storm surges would be particularly important in areas
where hurricanes are frequent, such as islands in the Caribbean Sea, the
southeastern United States, and the Indian subcontinent; if flood defenses were
not already erected, London and the Netherlands would also be at risk as a
result of winter storms. By contrast, because storm surges in these areas are
rarely more than 50 centimeters, flood damage would not be a major problem for
the Maldives (though the absence of high ground for evacuation would justify
treating the risk seriously). Erosion would be particularly important on U.S.
barrier islands, many of which have houses within 30 meters of the shore at high
tide. Because mangroves provide the major protection against flooding for many
countries too poor to erect flood defenses, wetland loss could be a major problem
there. Reduced drainage would be a chief concern in coastal areas frequently
flooded by river surges -- particularly deltas -- as well as other flat areas
such as the Florida Everglades, where water lingers several days after a
rainstorm.

Floods in Bangladesh would be worse for all of these reasons. In 1971, the
storm surge from a cyclone killed 300,000 people. Much of the country is flooded
by surges in both the Ganges and Brahmaputra Rivers; when the surges coincided
in 1987, about one-third of the country was under water. Although the
government has found it difficult to prevent people from cutting them down,
mangroves still provide important flood protection buffers. Should the
mangroves die, the outer islands erode, natural drainage !decline, and storm
surges rise a meter higher than today, much of the land not lost to inundation
would still experience consequences of sea level rise.

Saltwater Intrusion and Other Impacts on Water Quality

Sea level rise would generally enable saltwater to advance inland in both
aquifers and estuaries. In estuaries, the gradual flow of freshwater toward the

Titus

oceans is the only factor preventing the estuary from having the same salinity
as the ocean. Prevailing salinities result from the overall balance between
freshwater and processes that bring saltwater into the estuary such as tidal
mixing and advection. A rise in sea level would increase salinity in open bays
because the increased cross-sectional area would slow the average speed at which
freshwater flows to the ocean (see Figure 6).

Wetlands could experience increased salinity even if the salinity of the
adjacent bay did not increase. In many areas, wetland zonation depends on
proximity to open water, with salt marshes and salt-tolerant mangroves adjacent
to the bay, brackish wetlands farther inland, and freshwater marshes and swamps
still farther inland. If sea level rise inundates the most seaward wetlands, the
inland wetlands will be much closer to the bay, and hence exposed to higher
salinities. Although salt-tolerant species may be able to replace the freshwater
species, cypress swamps and floating freshwater marshes often lack a suitable
base for salt-tolerant wetlands, and saltwater intrusion is already converting
wetlands to open water lakes in Louisiana (Wicker et al., 1980).

Initial Condition

Freshwater

Saltwater

After Sea Level Rise

..........

... ..... .. ..

Figure 6. Increasing bay salinity due to sea level rise.

Problem Identification

Sea level rise could increase groundwater salinity for -two reasons. First,
some aquifers pumped well below sea level by human activities are recharged by
currently fresh rivers; if sea level rise enables saltwater to advance farther
up the Delaware River during droughts, for example, salty water would recharge
the aquifers in central New Jersey, rendering its watE!r unfit for human
consumption (Hull and Titus, 1986).

More common would be the problem confronting communities that rely on
unconfined aquifers just above sea level. Generally, these aquifers have a
freshwater "lens" floating on top of the heavier saltwater. According to the
Ghyben-Herzberg (Herzberg, 1961) principle, if the top of the aquifer is one
meter above sea level, the interface between fresh and saltwater is 40 meters
below sea level. If sea level rises one meter, aquifers will usually rise one
meter as well (Figure 7A-B). In areas where the freshwater always extends 40
meters below sea level, this situation would pose little problem.

In many areas, however, freshwater supplies are not so plentiful. Droughts
and wells can deplete the lens to a meter or less. Thus, wells that are
currently able to draw freshwater during a drought would be too deep if sea level
rose one meter. Fortunately, in areas with several meters of elevation, there
would still be as much freshwater; people would merely have to drill new wells.
In the lowest-lying areas, however, the actual amount of freshwater under the
ground would decline; the Ghyben-Herzberg principle implies that if the top of
the freshwater lens does not rise, the bottom of the lens will rise 40 times as
much as the sea (7B-C).

Consider the island of Tulhadoo (Republic of Maldives), which is entirely
less than 50 centimeters above high tide. Even when the ground is entirely
saturated, the lens can extend no more than 50 centimeters above sea level. But
the permeable coral material of the island allows much of this water to drain
fairly rapidly after storms, and evaporation and transpiration further lower
the water table during the typical dry season. As a result, the freshwater lens
is so small that people must obtain water by digging a hole, withdrawing a liter
or so of water, and refilling the hole, perhaps coming back the next day. A one-
meter rise in sea level would leave many more islands with this situation.

Sea 1 evel ri se coul d impai r water qual i ty i n other ways as wel 1 . Sal twater
intrusion could impair the effectiveness of septic tanks, while reduced drainage
could decrease dilution of the wastes and enable the septic discharges to remain
longer in the vicinity of wells. Reduced drainage could diminish the dilution
of wastes in rivers, and in some cases might enable them to flow upstream and
contaminate freshwater intakes. Higher water levels would compel municipal
authorities to close existing tidal gates more often, which would reduce
flushing.

By deepening shallow bodies of water, sea level rise could cause them to
stagnate. Fish ponds in Malaysia, the Philippines, and China have been designed
so that the tides provide sufficient mixing; deeper ponds, however, would
require more flushing. In the United States, many coastal housing developments
have finger canals to enable residents to park boats in their backyards. While

Titus

Upper limit of
water table

.......... ..

. . . . . . . . . . . . . . . . ..

Operating
Well ater lil -
Fre

Sal
Abandoned
ter
well

IMMM'
'g

'p=o@

....................

Figure 7. Impacts of sea level rise on groundwater tables. (A-B) According to
the Ghyben-Herzberg relation, the freshwater/saltwater interface is 40 cm below
sea level for every cm by which the top of the water table lies above sea level.
When water tables are well below the surface, a rise in sea level simply raises
the water table and the fresh/salt interface by an equal amount. Where water
tables are near the surface, however, drainage and evapotranspiration may prevent
the water table from rising. In such a case (C), the freshwater table could
narrow greatly with a rise in sea level: for every 1-cm rise in sea level, the
fresh/salt interface would rise 41 cm.
h

.......... .. ..

Prob7em Identification

the current practice of keeping them less than two meters deep prevents
stagnation today, it may not in the future if sea level rise! deepens them to
three meters.

Secondary Impacts

A number of other impacts of sea level rise that aria unimportant by
themselves may be important because of their impacts on inundation, erosion,
flooding, and saltwater intrusion. We briefly discuss changes in tidal ranges,
sedimentation, and reduced light reaching the bottom.

Sea level rise could change tidal ranges by (1) removing barriers to tidal
currents and (2) changing the resonance frequencies of tidal basins. Many
estuaries have tidal ranges far lower than found on the open coast because of
narrow inlets and other features that slow tidal currents; if sea level rise
inundates wetlands or erodes the ends of barrier islands, more water may flow
into and out of some estuaries and thereby increase the tidal range.

The implications of sea level rise for tidal resonance, however, is more
ambiguous. The Bay of Fundy, for example, has a tidal range of 15 meters because
the resonance frequency of the bay itself is very close to the diurnal frequency
of the astronomic tides on the ocean; the bay tends to increase the amplitude of
the tides. (One can simulate this effect by moving a hand back and forth in a
filled bathtub at different rates; at certain speeds -- the resonance frequency
of the tub -- the waves wash much higher than at other speeds.) Scott and
Greenburg (1983) note that the one-meter rise in sea level over the last few
centuries has altered the resonance frequency of the bay enough to increase the
tidal range by about a meter. This is just a coincidence, however; it is just
as likely that changes in sea level will shift resonance frequencies in a way
that reduces the tidal range. Nevertheless, tidal ranges also appear to be
increasing along the North Sea coast (Bruun, 1986).

Changes in tides could alter all of the basic processes discussed so far.
A greater tidal range would increase the inundation of dryland, while increasing
(or limiting the loss) of intertidal wetlands. Besides eroding inlets, greater
tidal currents would tend to form larger ebb tidal deltas, providing a sink for
sand washing along the shore and thereby causing additional erosion. Flooding
due to storm surges would also increase: other than resonance, the bathymetric
changes that might amplify or mitigate tides would. have the same impact on storm
surges. Finally, higher tidal ranges would further increase the salinity in
estuaries because of increased tidal mixing.

Under natural conditions, most of the sediment washing down rivers is
deposited in the estuary because of settling and flocculation. Settling occurs
downstream from the head-of-tide because the slowly moving water characterized
by estuaries cannot carry as much sediment as a flowing river. Flocculation is
a process by which salty water induces easily entrained fine-grained sediment to
coalesce into larger globs that settle out. A rise in sea level would cause both
of these processes to migrate upstream, and would thereby assist the ability of

Titus

wetlands in the upper parts 3@ estuarles to keep pace with sea level, while
hindering their ability in the 13tier parts.

A rise in sea level would also increase the size of waves. In shallow
areas, the depth of the water itself I imits the size of waves; hence deeper water
would permit larger waves. Moreover, erosion and inundation would increase the
fetch over which waves develop (i.e., the width of the estuary). Finally, the
breakup of barrier islands would enable ocean waves to enter some estuaries.

Larger waves could be the most important impact of sea level rise along
shallow (e.g., less than 30 cm at low tide) tidal creeks with steep, muddy
shores. The steep slopes imply that inundation would not be a problem. However,
with water depths one meter deeper, waves could form that were large enough to
significantly erode the muddy shores. Bigger waves could also increase the
vulnerability of lands protected by coral reefs. In many areas, these reefs
protect mangrove swamps or sandy islands from the direct attack by ocean waves;
but deeper water would reduce the reef's ability to act as a breakwater. The
extent to which this would occur depends on the ability of the coral to keep pace
with sea level rise.

Finally, sea level rise could decrease the amount of light reaching water
bottoms. The depth at which submerged aquatic vegetation can grow depends
primarily on how much light reaches the bottom. Corals in clear water can grow
10 meters below the surface, whiie the more productive vegetation in some turbid
areas is generally found in water less than 2 meters deep. By limiting the
ability of light to reach the bottom, deeper water would reduce the productivity
of virtually all submerged vegetation to some degree.

Other Impacts of Global Warminq

One must consider the implications of sea level rise in the context of other
impacts of global warming, which could alter all of the impacts except
inundation. Warmer temperatures could convert marshes to mangroves. if
hurricanes or storms become more severe (Emmanuel, 1988), flooding and erosion
will be worse. More droughts would exacerbate salinity and other water quality
problems, while if droughts become less frequent, most salinity problems
associated with sea level rise might be completely offset. Low islands, However,
are an important exception; if an island with a few meters' elevation comes to
resemble Tulado in the Maldives, wells will be of little use during the dry
season.

Interaction with Human Activities

The impacts of sea level rise cannot be fully understood without some
discussion of human activities in the coastal zone, the ways humanity has already

Problem Identification

disrupted natural coastal environments (partly in response to historic sea level
rise), and the activities that can be expected if current policies continue..

In this section, we focus primarily on the implications for (1) river
deltas, (2) other wetland shorelines, (3) beach resorts, and (4) coastal cities.

River Deltas

Most of the basic processes described above would manifest themselves in
river deltas. Because deltaic wetlands and lowlands were created by the
deposition of river sediments, these lands are generally within a few meters of
sea level and hence vulnerable to inundation, erosion, and flooding. During
droughts, saltwater intrusion is already a problem in many of these areas.
Nevertheless, under natural conditions, the sediment washing down the river could
enable at least a significant fraction of the typical delta to keep pace with sea
level rise.

Human activities in many deltas, however, have disabled the natural ability
of deltas to create land. Over the last few thousand years the Chinese -- and
over the last few hundred years the Dutch -- have erected sea dikes and river
levees to prevent flooding from storm and river surges. As a result, the annual
floods no longer overflow the river banks, and as sea level rises, it has left
the adjacent land below sea water level, necessitating more coastal defense to
prevent the land from being inundated as sea level rises.

Over the last century, the United States has sealed off Mississippi River
distributaries, forcing the flow of water through a few main channels, to prevent
sedimentation in shipping lanes. More recently, river levees have also been
constructed. Unlike the Chinese and Dutch deltas, however-, the Mississippi
Delta is not encircled with dikes; as sea level rises and the deltaic mud
settles, Louisiana is losing 100 square miles of land per year (Louisiana Wetland
Protection Panel, 1988). In Egypt, the Aswan Dam prevents the Nile River from
overflowing its banks, and its delta is now beginning to erode as well (Broadus
et-al., 1986). Similarly, a major dam on the Niger River is causing the coast
of Nigeria to erode 10-40 meters per year (Ibe and Awosika, 1989).

The natural land-building processes in some major deltas, are still allowed
to operate. Most notable is Bangladesh, located in the delta of the Ganges and
Brahmaputra Rivers. About 20 percent of the nation is less than one meter above
sea level, and close to one-third of the nation is regularly flooded by annual
river surges. People in agricultural areas are generally accustomed to the
flooding, which in addition to depositing sediment provides farmland with
important nutrients. Nevertheless, floods have disrupted the capital, and the
government is considering river levees to curtail flooding.

Paradoxically, a one-meter rise in sea level threatens to permanently
inundate deltas that are protected from river flooding, while protected areas may
be able to avoid inundation through natural, sedimentation. Nevertheless, at
least parts of these deltas would probably be inundated. In the case of

Titus

overcrowded nations such as Bangladesh, the resulting migration away from the
coast may exacerbate social tensions and possibly result in massive emigration.

Other Wetland Shorelines

Although human activities would have the greatest impact on deltaic
wetlands, they would also influence the ability of other coastal wetlands to
survive a rising sea level. Perhaps most important, ecosystems could shift
landward under natural conditions in most areas. However, in many areas people
have already developed the adjacent dryland onto which the ecosystem would have
to migrate. If these areas are protected with bulkheads or levees, the wetlands
will be squeezed between the rising sea and the flood-protection structure.

Current efforts to control water pollution may have a beneficial impact on
wetlands. Healthy marshes and swamps in unpolluted estuaries would be more
likely to maintain the vertical accretion rates necessary to keep pace with sea
level rise. Furthermore, to prevent estuaries from being polluted by septic
tanks, some jurisdictions require houses to be set back 50-100 meters from the
wetlands; these setbacks will leave some room for landward migration.

Beach Resorts

Along the ocean coasts of Australia, Brazil, Nigeria, Portugal, the United
States, and many other nations, one of the most important impacts of sea level
rise would be the threat to recreational beach communities. Particularly in the
United States, even a small rise in sea level would erode the existing
recreational beaches and leave oceanfront houses standing in the water. In areas
where these buildings are protected by seawalls, the entire beach would vanish,
removing the primary reason people visit these communities in the first place.

Moreover, many resorts are located on barrier islands where typical
elevations are only one or two meters above sea level. Although natural barrier
islands can migrate landward, developed barrier islands do not, both because
structures prevent the landward transport of sand and because public works
departments tend to bulldoze back onto the beach whatever sand is washed
landward. Thus, in addition to oceanside erosion, the low bay sides of these
islands would be threatened with inundation.

Coastal Cities

Throughout history, small towns have often been relocated in response to
erosion and sea level rise; but cities have generally erected the structures
necessary to remain in their current locations. One can reasonably expect that
sea level rise will force Dakka, Lagos, Shanghai, and Miami to erect the dikes
and pumping systems necessary to avoid inundation. While the primary
socioeconomic impact in industrialized nations many be higher taxes, budgets in
developing nations may be constrained, forcing them to reduce expenditures
on health, education, economic development, and other requirements.

Problem Identification

Many cities not immediately threatened with inundation would be flooded,
While flood defense is possible, the history of coastal protection suggests that
this generally will happen only after a disaster or near -cat astrophe demonstrates
the need for these projects; one can only hope that the latter occurs first.
Case studies in the United States suggest that areas flooded once or twice a
century today will be flooded every decade if sea level rises one meter (Barth
and Titus, 1984).

Environmental Implications

The impacts of sea level rise on ecosystems can be broadly classified into
effects of (1) wetland loss, (2) salinity increases, and (3) beach erosion.

Estuarine fisheries depend on coastal wetlands because they account for a
major fraction of primary productivity and because they provide important
nurseries owing to their ability to protect fish larvae and juveniles from
predators. Although primary productivity depends on the total area of wetlands,
the productivity of fisheries is widely believed to depend more on the total,
length of wetland/water interfaces (Browder et al., 1985); unless there is a
channel through the wetlands, fish rarely swim more than a few tens of meters
into the wetlands.

Al though sea 1 evel ri se woul d reduce the area of wetl ands,, at f i rst i t woul d
tend to increase the length of the wetland/water interface. Figure 8 illustrates
the disintegration of the birdfoot delta of the Mississippi River, where many
researchers believe that wetland loss temporarily improved fish catches. In the
long run, however, the decline in wetland area will eventually decrease the total
length of the interface, with a roughly proportional impact on estuarine
fisheries.

In industrialized nations, the decline of these fisheries would imply higher
prices for shrimp, crab, flounder, and other fish that depend on marshes for
parts of their life cycles, as well as chicken, which are often fed fishmeal from
estuarine species. In some developing nations, however, the decline in these
fisheries could threaten subsidence.

Increasing estuarine salinity would also threaten some seafood species,
largely because the major predators of these species are unable to tolerate
freshwater. Even today, excessive salinity during droughts has been a
contributing factor in the decline of oyster harvests in the Delaware and
Chesapeake Bays (Gunter, 1974; Hull and Tortoriello, 1979).

Under natural conditions, a rise in sea level would not threaten life along
the beach; ecosystems would merely migrate landward. However, the presence of
buildings behind the beaches would often prevent landward migration. Along the
coast of Florida, for example, beach erosion is already forcing sea turtles in
some areas to build their nests under people's houses.

Titus

ACTIVE DELTA 1958 ACTIVE DELTA 1978

AIX---
.-P @fu A_

Ige

Legend
Scale Symbol Habitat Type
IS 0 2.S 5.0 7.5 10.0 Marsh
Forested Welland
Miles El Upland
13 Dredge Deposit

Figure 8. Wetland loss at the mouth of the Mississippi River (National Coastal
Ecosystems Team, U.S. Fish and Wildlife Service).

SOCIOECONOMIC IMPLICATIONS FOR PARTICULAR NATIONS

We now examine the implications for two nations: the United States and the
Republic of Maldives. Future drafts of this paper for the IPCC work group and
report will have a more balanced treatment.

United States

If no measures were taken to counteract its effect, a one-meter rise in sea
level would inundate 7,000 square miles of coastal lowlands and a similar area
of wetlands. Recreational beaches in the Northeast and Mid-Atlantic would erode
about 50-100 meters, while those in the Southeast and west coast would erode
100-200 meters (Titus, 1986). Moreover, coastal cities such as Charleston,
South Carolina, and Galveston, Texas, would experience three times as much damage
from a 10-year storm than they do today (Kana et al., 1984; Leatherman, 1984).
Finally, saltwater migrating upstream in the Sacramento Delta, Delaware River,

Problem Identification

and the Everglades would threaten the water supplies of southern California,
Philadelphia, New York, and Miami, respectively (Williams, 1989; Hull and Titus,
1986, Miller et al., 1989).

Because the United States is a wealthy nation, the cost of protecting
developed areas from a rise in sea level would generally be affordable. Spread
over the course of a century, the $100 billion necessary to protect the 700
square miles of most densely developed areas would amount to approximately $3,000
dollars per acre per year -- hardly a welcome prospect, yet hardly beyond the
taxing powers of local governments given current property values, which
frequently exceed $1 million per acre on barrier islands and are rarely less than
$200,000 per acre in developed areas.

The most notable exception is the Mississippi River Delta, which would
account for 20 percent of the dryland and half of the wetland lost. Whether the
area is protected with dikes or the land is allowed to vanish, the loss of
wetlands and the fisheries that depend on them would drive traditional Cajun
fishermen away to more fertile areas or into new professions. While the music
and cooking the Cajuns have contributed to American society would probably
endure, the core of the culture has been life in the marshes and swamps of
Louisiana; without the homeland of their heritage, the ability of Cajuns to
maintain a distinct cultural identity is doubtful. Only by dismantling the
infrastructure that has disabled natural deltaic processes could these wetlands
survive; doing so, however, would force ships bound to the Port of New Orleans
to pass through a set of locks, causing delays that under current policies are
even less acceptable (Louisiana Wetland Protection Panel, 19138).

Even in Louisiana, the major socioeconomic impact would not be the economic
impact of sea level rise, but its environmental implications. Although wetland
loss elsewhere would not be on such a massive scale, over half the wetlands in
most estuaries would be lost. In many areas, the wetlands would erode up to a
bulkhead protecting development, making it impossible for many fish to find the
marshes necessary for reproduction (Titus, 1988). Sport fishing and duck hunting
would decline; the general population would notice the impacts as prices of
crabs, shrimp, and other estuarine species began to reflect 'levels of scarcity
that already apply to oysters and lobsters.

So far, the news media have focused the most on implications for barrier
islands and other beach resorts. Unless remedial measures are taken, even a
small rise in sea level would substantially increase the vulnerability of these
communities, which already face the risk of being devastated if a major
hurricane crosses their paths. These risks would be further compounded if
hurricanes become more intense as a result of global warming. Nevertheless, the
value Americans place on owning or renting a seaside cottage suggests that the
measures necessary to defend these resorts from sea level rise would be
affordable.

Titus

Republic of Maldives

This island nation consists entirely of coral atolls. As a result, the
entire nation is less than four meters above high water. Several of its most
populated islands, including the capital, are less than two meters above high
tide; and some islands are less than 50 centimeters above high tide.

Over 90 percent of the islands are uninhabited. Because storm surges rarely
exceed 25 centimeters, people hardly considered elevation in deciding which
islands to settle. In the Baa Atoll, for example, Tulhadoo, about 40 cm above
high water, has five times the population of the similarly sized island of Goia,
which has elevations greater than three meters. The most important distinction
today is that the higher islands have ample groundwater, while lower islands have
little if any during parts of the year. Thus, the most immediate impact of sea
level rise would be to further diminish the availability of freshwater.
If sea level rises a meter, the lower islands would be threatened with
inundation. Although it would be possible to move to higher areas, people
outside the capital are generally so attached to their home islands that many
have visited other islands only a few times in their lives; efforts to encourage
migration to less developed islands are generally recognized as a major factor
contributing to the downfall of their previous president.

In the very long run, the Maldives could survive a rising sea level only if
measures were taken to elevate the islands. Fortunately, the nation would have
to focus only on protecting land for industrial and residential uses; the greater
areas necessary for food production in their case refer primarily to the sea
itself, which is largely unaffected by changes in sea level. Despite the
potential for remedial measures, the prospect of the entire nation being
inundated motivated the president of this nation to become the first head of
state to address the United Nations and the British Commonwealth on the
implications of global warming.

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Ali, S. I. and S. Huq. 1989. International Sea Level Rise: National Assessment
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A Challenge for This Generation. New York: Van Nostrand Reinhold.

Problem Identification

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Dean, R.G., et al. 1987. Responding to Changes in Sea Level. Washington, DC:
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U.S. Environmental Protection Agency. 1989. Potential Impacts of Global Climate
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Emmanuel , K.A. 1988. The dependence of hurricane intensity on climate.
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Fairbridge, R.W., and W.S. Krebs, Jr. 1962. Sea level and the southern
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Prob7em Identification

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Titus

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Agency.

REASONS FOR BEING CONCERNED ABOUT RISING SEA LEVEL

DR. LOUIS W. BUTLER
Director of Planning
National Ocean Service
National Oceanic and Atmospheric Administration
Washington, DC

A GLOBAL PERSPECTIVE

Value of the Coastal Zone

This paper lays out the resources at risk to a rise in sea level . The
local economies of virtually all coastal communities rely heavily on the
quality of their estuaries and adjacent coastal areas. Coastal habitats
such as wetlands, dunes, and beaches are important areas for fish and
wildlife, including many endangered species, as well as for many types of
recreation.

Coastal zones provide critical habitat for commercially important
fisheries, filter and process agricultural and industrial wastes, buffer
inland areas against storm and wave damage, and help generate revenues from
a variety of commercial and recreational activities. Commercial,
recreational, and subsistence fisheries are, at the very least, important
to the economies of most nations and are the lifeblood of many others.

Uses of the Coastal Zone Today

In many parts of the world, as a result of population growth and
development, the natural function of coastal zones and their resources is
being degraded and impaired. This is particularly apparent in deltaic
regions served by large rivers and inhabited by large human populations.

River deltas are vulnerable to the activities of upstream states. For
example, activities by India, Nepal, China, and Bhutan all affect the flow
and water quality characteristics of the Ganges, which is felt downstream
by Bangladesh. Disputes arise over the construction of dams on major
rivers, over the use of major tributaries, and over river diversions.
Upstream activities can affect water availability, the ecology of the delta,
and the formation and subsidence rates of the delta, which normally offers
some protection from storm surges and sea level rise. Other obvious
examples are the Nile and the Mississippi Deltas.

Problem IdentiFication

Decreased or diverted riverflow also can lead to increased saltwater
intrusion and thus to drastically altered biological productivity.
Declining health of salt-sensitive mangrove forests may lead to loss of
habitat for many species of fish and shellfish and to increased loss of
entrapped sediments.

Removal of groundwater or hydrocarbons from deltas can accelerate
greatly the rate of local subsidence. Subsidence in low-lying deltas, either
natural or exacerbated by fluid withdrawal, can accentuate greatly the
apparent local rise in sea level. Clearly, coastal and fluvial planning for
future coastal zone uses requires careful attention in view of potential
human-induced changes in global climate and associated sea level rise.

Potential Threats

Most shorelines have already experienced significant and almost
constant change, with enormous commercial, recreational, and environmental
values at risk. Flooding, beach erosion, habitat modification and loss,
structural damage, and silting and shoaling (resulting from natural factors)
all pose major public safety and economic consequences. Yet, while these
risks are substantial, the benefits of coastal resources in many areas
significantly outweigh them and continue to attract human activity and
development. When a human-induced, accelerated rise in global sea level is
added to the equation, however, the potential for loss of life, injury, and
economic damage increases.

Some general observations can be made about the differences in
vulnerability to sea level rise of industrialized and developing countries.
Most major cities in industrialized countries probably will be protected
from sea level rise, but at great expense. In developing countries,
however, sea level rise will be most severely felt by exposed coastal
populations and by agricultural developments in deltaic areas. Three highly
populated developing countries -- India, Bangladesh, and Egypt -- are
thought to be especially vulnerable because their low-lying coastal plains
are already extremely susceptible to the effects of storms. Since 1960,
India and Bangladesh have been struck by at least eight tropical cyclones,
each of which killed more than 10,000 people. In late 1971), storm surges
killed approximately 300,000 people in Bangladesh and reached over 150
kilometers inland over the lowlands. Recent estimates suggest that a
climatically induced one-meter rise in sea level would cover scarce arable
land in Egypt and Bangladesh presently occupied by 8 and 10 million people,
respectively. A far greater fraction of the population of these countries
would be threatened by the increased consequences of storms.

Small island nations are also especially vulnerable to sea level rise
and to the other coastal effects of climate change. This vulnerability is
reflected in their very high ratios of coastline length to land area. The
most seriously affected island microstates are those consisting solely, or
mostly, of atolls with little or no land at all a few meters above sea

Butler

level. The majority of developing island microstates are also experiencing
rapid rates of population growth. Moreover, they are most frequently
characterized by having large proportions of their populations in low-lying
coastal areas. The location of most small island countries in the latitudes
where tropical cyclones may be experienced further adds to their
vulnerability. The effects of such disasters, while of smaller magnitude
than those described above for some of the world's great deltas, are
proportionally often much more devastating.

A Need for Action

These circumstances require political, scientific, legal, and economic
actions at the international and national level. It is imperative that such
actions focus on human safety and on sustainable approaches to the
management of coastal resources.

One of the first steps is to heighten awareness among governments and
citizens alike of the possibility of sea level rise and its potential
impacts in the coastal zone.. It is important to begin now the process of
identifying, analyzing, evaluating, and planning for adaptive responses to
build a foundation for timely implementation of response strategies, should
the need arise.

Even though sea level rise is predicted to be a relatively gradual
phenomenon with site-specific consequences, strategies appropriate to unique
physical, social, economic, environmental, and cultural considerations may
require long lead times.

Nature has provided us some time -- it must be used wisely by all
nations, collectively and individually.

A FORECAST FOR GLOBAL CHANGE

Global Warming

There is growing consensus among scientists that the atmospheric
buildup of greenhouse gases may lead to global climate changes and to an
associated acceleration in the rate of sea level rise.

The IPCC Working Group 11 has projected a series of global consequences
for a doubling of the carbon dioxide concentration in the atmosphere by the
year 2050. It constructed its scenario based on the global warming
projections of Working Group I, including an increase in air temperature of
3.50C and a sea surface temperature increase of up to 2% by the year 2050.

During this period, seawater may become slightly more acidic, in turn
releasing more heavy metals in a biologically available, toxic form. The
intensity and areal extent of coastal upwelling may decrease, thereby
lowering the level of primary food production in marine ecosystems. The

Problem Identification

amount, rate, and regional variability of these consequences aria uncertain.
In general, the global warming scenario assumed by Working Group II would
lead to a reduction in fishery productivity and a partial loss of spawning
areas in the coastal zone, with a net redistribution of fishery regions.

An accelerated rise in sea level would have direct effects in the
coastal zone. While the rise in sea level would most likely be incremental,
the damages from flooding and erosion related to this rise would occur
during extreme events such as tsunamis or. storm surges associated with
hurricanes and typhoons.

Climate changes associated with global warming probably will also
affect freshwater availability and quality, food productivity, and access
to other resources, goods, and services. The societal impacts of these
climate changes could be widely distributed, but they are likely to be felt
more severely by poorer nations, posing important and still unresolved
questions about equity, fairness, and international environmental ethics.

An Accelerated Rise in Sea Level

Current information from the IPCC Working Group H indicates that,
while secular sea level trends extracted from tide gauge! records over the
last century indicate an average global sea level rise of 1 to 2 mm/year,
new models of climatic warming and thermal expansion of the ocean, and
considerations of melting of small glaciers and large ice sheets, suggest
an average rate of global sea I evel rise of 4 to 6 mmlyear by the year 2050.
This projected rise of 25 to 40 cm by the year 2050 is 2 to 6 times faster
than that experienced during the last 100 years, and would result
principally from the thermal expansion of the ocean and melting of small
mountain glaciers. The Working Group I concluded from its modeling studies
that the contribution to sea level rise from melting of the Greenland ice
sheet may be offset by an addition of ice to Antarctica and a consequent
lowering of global sea level. Working Group I believes that there is enough
inertia in the human-induced global warming that some rise in sea level is
probably inevitable in the future.

In addition to sea level rise, a number of researchers have suggested
that extreme events may occur more regularly as a result of climate change.
For example, increased ocean temperatures may result in more frequent
occurrence of tropical cyclones. Of particular concern is the effect of
storm surges, associated with tropical cyclones, which in conjunction with
increased sea levels may play havoc on low-lying coasts. Inundation of
coastal areas is already common during tropical cyclones and any increases
in the extent or frequency of inundation may render numerous heavily
populated areas marginal or uninhabitable.

Uncertainties

The complexity of climate modeling means that the necessary research
may be slow and difficult, and global monitoring of sea level may not detect

Butler

significant changes for another decade. Consequently, considerable
uncertainties remain about the nature, timing, magnitude, and regional
details of climate changes.

POTENTIAL IMPACTS OF CLIMATE CHANGE AND ASSOCIATED
SEA LEVEL RISE

Inundation, Erosion, and Flooding

A rise in sea level would (1) inundate wetlands and lowlands, (2)
erode shorelines, (3) exacerbate coastal flooding, (4) increase the salinity
of estuaries and aquifers and otherwise impair water quality, (5) alter
tidal ranges in rivers and bays, and (6) change the locations where rivers
deposit sediment.

For example, a one-meter rise in sea level could inundate 15% of
Bangladesh, and a two-meter rise could inundate Dhaka (the capital of
Bangladesh) and over one-half of the populated islands of the Republic of
Maldives, an atoll in the Indian Ocean. In the Pacific, the atolls of
Tokelau, Tuvalu, Kiribati, and those of the Marshalls could be devastated.
Shanghai and Lagos -- the largest cities of China and Nigeria, respectively
- - are 1 ess than two meters above sea 1 evel , as i s 20% of the popul at i on and
farmland of Egypt.

Sea level rise will increase the risk of storm-related flooding. The
higher base for storm surges would be particularly important in areas where
hurricanes and typhoons are frequent, such as islands in the Caribbean Sea,
the southeastern United States, the tropical Pacific, and the Indian
subcontinent; had flood defenses not already been erected, London and the
Netherlands would also be at risk from winter storms.

Population and Infrastructure

In some circumstances, there may be a need to relocate people or even
entire communities. The issue of resettlement, while exerting major
financial demands (particularly in developing countries), has an even
greater effect on the social and cultural norms of the community being
relocated. The loss of the traditional environment, which normally sustains
an economic and cultural base and provides for recreation for the community,
could severely disrupt family life and create social instability with a
resulting negative psychological impact on the entire population, especially
on the young and the elderly.

Community disruption and other negative social impacts associated with
sea level rise and its consequences can also have severe, although
different, effects on an industrialized country. The scale of loss of
infrastructure, commercial, and community support systems can prove
astronomically expensive as a result of the high value of the installations
and equipment.

Problem Identification

Backwater effects can cause the lower river water levels to rise with
rising sea level, affecting certain river-related infrastructural facilities
such as bridges, port structures, quays, embankments, and river-training
works.

Higher water levels in the lower reaches of rivers and adjacent coastal
waters may affect the drainage capacity of adjacent lands and result in
damage to production activities and facilities such as roads and buildings.

Ecosystems and Living Resources

Estuaries, lagoons, deltas, and wetlands are all components of the
coastal zone ecosystem, usually characterized by intensive -tidal influence,
high turbidity and productivity, and a high degree of human activity
(fisheries, navigation, recreation, waste disposal). From a conservation,
economic, and ecological point of view, they are the most; valuable areas
found in the nearshore shallow waters.

The main potential effect of sea level rise in shallow coastal waters
is an increase in water depth. Intertidal zones may be modified radically
and mangroves could disappear. The physical and morphological boundary
conditions of shallow waters may change considerably, affecting the
functioning of ecological systems. In turn, this may cause the loss of
natural resource values, such as bird life, fish spawning and nursery
grounds, and fish and shellfish production.

In general, the effects on shallow coastal ecosystems are strongly
determined by local circumstances, and a good understanding of the physical
and biological processes is required to forecast local impacts. But if the
accretion of sea floor sediments cannot keep pace with rising waters and
inland expansion of intertidal area is not possibIle (because of
infrastructure or a steeply rising coast), major impacts are to be expected.

Coastal wetlands provide critical habitats for high percentages of
commercially important fisheries in many countries. They also filter and
process agricultural and industrial wastes, buffer coastal areas against
storm and wave damage, and help generate large revenues from a variety of
commercial and recreational activities. The United States estimates that
coastal wetlands contribute to an annual marine fisheries harvest valued at
over $10 billion. Equally important may be the wetlands contributions to
subsistence fisheries that are critical for many coastal nations.

Raised sea levels may influence some coastal marine fishes by altering
the shallow estuaries in which the juveniles find early shelter and food.
If existing shorelines are maintained by embankments,, these shallow
estuaries with their productive mudflats may become too deep. A change in
estuarine salinity also is likely to have an effect on juvenile fish and
their food, as will changes in inflow and -Nutflow currents.

Butler

Despite numerous protective laws, the degradation of estuaries and the
disappearance of coastal wetlands continues because of shoreline erosion,
landfill developments, flow diversions, turbidity, and sea level rise. An
accelerated rise in sea level would only exacerbate these losses.

The estuarine response to climate change is likely to be a slow but
continually adjusting environment. With a change in estuarine vegetation,
there will be an adjustment in the animal species living in and around the
estuary margins. An increase in mudflat vegetation such as the mangrove,
will trap fine sediments within a harbor and gradually convert sand banks
to mudflats. The wetter climate conditions projected by many models would
lead to increased flow and sediment yields and consequently to increased
turbidity of the estuary waters. These changes, together with a rise in
sea level of up to one meter over the next 100 years, would modify the shape
and position of many banks and channels within the estuary and permanently
submerge others. Provided there are no barriers, wetlands and salt marshes
around the landward margins of the estuary may increase with rising sea
level. Where barriers occur, wetlands may be submerged by the rising water
levels and permanently covered by shallow waters. Pastoral land around the
estuaries may become saline and, hence, unproductive.

The adjustments to global sea level rise, outlined above for the
estuarine environment, indicate the possibility of some far-reaching
impacts. There will be changes in fisheries and nursery functions of the
estuaries together with changes in plant and bird life as the sediment and
streamflow regimes adjust to the changing level of the sea.

EXISTING PROBLEMS IN COASTAL ZONES:
A CONCERN OF IPCC?

DR. ROBBERT MISDORP
Ministry of Transport and Public Works
Tidal Waters Division
Koningsaade 4
The Hague, The Netherlands

INTRODUCTION

The effects of an acceleration of sea level rise on coastal lowlands can
be summarized as an inundation of parts of the wetlands and the coastal plains,
an increase in flooding frequency, an increase in the rate of coastal retreat
and coastal erosion, and an increase in saltwater intrusion (UNEP/Delfts
Hydraulics, 1988; Titus, 1989). These types of impacts, however, also may result
from other processes, including subsidence and upstream river management (Figure
1). These problems, which are related to present detrimental coastal processes
other than sea level rise, are defined as the "existing problems" in the coastal
zone.

The causes of the existing problems are often human induced:

� Population pressure in the coastal zone leads to occupation, an increase
in human activities, and exploitation of coastal areas.

� The exploitation of natural resources (oil/gas/water) often results in
subsidence.

� Upstream river construction, such as the building of dams, retains the
sediment supply that otherwise would nourish the coastal zone.

All of these processes increase coastal erosion, and lead to inundation of
the floodplains and saltwater intrusion, as will the expected acceleration of
sea level rise (Figure 2).

One of the tasks of the IPCC-Response Strategies Working Group-Coastal Zone
Management subcommittee is to unravel existing and future problems in the coastal
zone and their respective causes.

sea level rise

seaward expansion
population

dune

ocean lagoon

----------------------------
. . . . ... ... ... ..
.. .. ..... .
K
............ . ....
...........
................
...........
...........
. . ........... .. .

Figure 1. The main factors affecting coastal zones.

SOME EXAMPLES OF EXISTIMG COASTAL PROBLEMS

Subsidence in coastal zones that is mainly related to human activities is
illustrated by the following examples:

� The Chao Phraya delta basin in Bangkok (5.5 million inhabitants) shows
an increase of maximum subsidence (Nutulaya, 1988) from 1.2 m/century
(1933-1978) to 7 m/century (1978-1987) (Figures 3 and 4).

� An example of a low rate of subsidence is found in the Netherlands.
The subsidence in the western part of the Netherlands is tectonic in
origin and amounts to maximum values of only slightly more than 0.06
m/century (Figure 5). This subsidence rate of the Pleistocene subsoil
was observed during the period 1926-1985 (Noonen, 1.989). In coastal
areas with maximum subsidence rates, retreat of the coastline (mean low
water line) amounted to 150-220 m/century (Kohsiek, 1988) during 1885-
1985.

� Coral mining on the foreshore of Male (50,000 inhabitants/1.6 kM2), the
ppopmom

principal island of the fast-growing Maldives (maximum height 2-3 m above
sea level) is deepening the foreshore, with a subsequent increase in wave
action and coastal erosion (UNEP/Delfts Hydraulics, 1989) (Figure 6).

Misdorp

.............. . .....

N.M.

PRECIPITATION
EVAPOTRANSPIRATION
SEA LEVEL RISE TEMPERATURE

SALTWATER COASTAL EROSION STORM DIRECTION A
INTRUSION AND INUNDATION FREOUENCY
F--

LOSS OF LIFE, LAND,
CAPITAL, ECO-SUSTAINABILITY
-I-
COASTAL ZONE MANAGEMENT PROBLEMS

Figure 2. Schematic representation of the main factors affecting the coastal
zone.

The construction of dams in rivers is accompanied by withdrawal of sediments
on their way to the coast:

The sediments of the annual highly turbid Nile flood are completely
trapped in the artificial Lake Nasser (500 x 10 km) since the
construction of Aswan High Dam (1964). Water and sediment discharges
of the Nile's branches into the Mediterranean Sea ceased to exist after
1964. The subsequent observed acceleration of coastal retreat of the
protruding subdeltas of the Nile Delta reached maximum values of 150
m/year (Rosetta peninsula, Figure 7; Misdorp and Pluym, 1986). Since
1964, the overall yearly coastal erosion along the 250-km-long Nile Delta
coastal zone has been on the same order as the Nile sediment discharge
before 1964 (about 100 million m').

40 70 90 70 90

70 chao phraya 70
river
chao phraya
river

3.0

0,8 30 5.0 30
Banowk 1.0
1,2
00 7.

legend legend
contour of subsidence 00 contour of subsid 00
M/Century m/century
0 5 1 Okm
0 5 1 Okm

@.w
,U:
Tt.151.
me I-T;
f 0- k
u si end *A h -d-b"am,
b
7
ep
Ur
Y.
ep"'.

Figure 3. Subsidence of the Bangkok basin Figure 4. Subsidence of the Bangkok basin
(1933 to 1978). (1978 to 1987).

Misdorp

X 10
Average coastal retreat/ V-1
advance 1885-1985 in m/y

a&ar= rena
N
I

I's 0 1.5
X

North Sea

West Germany
X 10 W,
(-777@
-OL Subsidence and uplift
(1926-1980) in cm/century
6 uplift

Belgium 0
6 subsidence

Figure 5. Coastal retreat/advance and subsidence in the Netherlands.

Maldives india
Population pressure

Seaward expansion

+2m- waves waves

-3m

Of
20m

Figure 6. Coastal zone activities in the Maldives.

99
wavesJI/I
-7
PF

Adaptive Options

rn/y 200 Retreat of Rosetta Promontory
Nile Delta, Egypt
observed
150 predicted
(math. model excl.
100 coastal protection)

Retreat 50 %%

No- Year AD

Advance
1900 1964 2000 2100
1
Aswan High Dam construction

Figure 7. Maximum annual retreat rate (m/year observed during 1900-1985
and calculated by mathematical model 1985-2110) (excluding coastal protection
measures).

EXISTING COASTAL MANAGEMENT PROBLEMS AND IPCC

Two policies are possible for handling the existing and 'Future problems in
coastal zones: adaptation or limitation of the cause.

Limitation of the causes of existing problems in the coastal zone means:

� intensifying measures to reduce population pressures;

� changes in the manner of exploitation of coastal areas: water/oil/gas
extraction and upstream river management.

These types of limitation measur es should receive high priority.

100

HOLDING BACK-THE SEA

JODI L. JACOBSON
World Watch Institute
Washington, D.C.

A quick study of a world map illustrates an obvious but rarely considered
fact: much of human society is defined by the planet's oceans. The boundary
between land and water determines a great deal that is often taken for granted,
including the amount of land available for human settlement and agriculture, the
economic and ecological productivity of deltas and estuaries, the shape of bays
and harbors used for commerce, and the abundance or scarcity of freshwater in
coastal communities.

The rapid settlement of coastal areas'over the past century implies tacit
expectation of a status quo between sea and shore that, according to most
scientific models, is about to change. On a geological time scale, sea level
is far from static. Cycles of cooling and warming that span 100,000 years,
accompanied by glaciation and melting, keep the level of the oceans in constant
flux. Still, for most of recorded history, sea level has changed slowly enough
to allow the development of a social order based on its relative constancy.

Global warming will radically alter this. Increasing concentrations of
greenhouse gases in the atmosphere are expected to raise the earth's average
temperature between 2.5 and 5.5 degrees Celsius over the next 100 years. In
response, the rate of rise in sea level is likely to accelerate from thermal
expansion of the earth's surface waters and from a more rapid melting of alpine
and polar glaciers and of ice caps. Although the issue of how quickly oceans
will rise is still a matter of conjecture, the economic and environmental losses
of coastal nations under various scenarios are fairly easy to predict. One thing
is clear: no coastal nation, whether rich or poor, will be totally immune
(Hansen et al., 1988).

Accelerated sea level rise, like global warming, represents an environmental
threat of unprecedented proportion. Yet most discussions of the impending
increase in global rates obscure a critical issue -- in some regions of the
world, relative sea level (the elevation as measured at a given point on the map)
is already rising quickly. Bangladesh, Egypt, and the United States are just
a few of the countries where extensive coastal land degradation, combined with

101

Problem Identification

even the recent small incremental changes in global sea level, is contributing
to large-scale land loss. These trends will be exacerbated in a greenhouse
world.

A preliminary assessment of the likely effects of global and relative sea
level rise done by the United Nations Environment Programme (UNEP) in 1989
identified the 8 regions and 27 countries at greatest risk. While pointing out
that potential losses from rising seas are far greater in some areas than others,
the report warned that a large majority of nations will be affected to some
degree by higher global average rates, since only 30 countries in the world are
completely landlocked (UNEP, 1989).

Low- to middle-range estimates by the U.S. Environmental Protection Agency
(EPA) indicate a warming-induced rise by 2100 of anywhere from a half-meter to
just over two meters. A one-meter rise by 2075, well within the projections,
could result in widespread economic, environmental, and social disruption. G.P.
Hekstra of the Dutch Ministry of Housing, Physical Planning, and Environment
asserts that such a rise could affect all land up to five meters elevation.
Taking into account the effects of storm surges and saltwater intrusion into
rivers, he estimates that 5 million square kilometers are at risk. Although only
a small percentage of the world total -- about 3 percent -- this area encompasses
one-third of global cropland and is home to a billion people (Hoffman et al.,
1986, 1983; Hekstra, 1989).

As sea level rises, coastal communities face two fundamental choices:
retreat from the shore or fend off the sea. Decisions about which strategy to
adopt must be made relatively soon because of the long lead time involved in
building dikes and other structures and because of the continuing development
of coasts. Yet allocating scarce resources on the basis of unknown future
conditions -- how fast the sea will rise and by what date -- entails a fair
amount of risk.

Questions also arise about how far nations should go in safeguarding and
insuring investments already made in coastal areas. Protecting beaches, homes,
and resorts can cost a country with a long coastline billions of dollars -- money
that is well spent only if current assumptions about future s-ea level are borne
out. Assessing the real environmental costs is difficult because traditional
economic models do not reflect the fact that structural barriers built to hold
back the sea often hasten the decline of ecosystems important to fish and birds.
Moreover, protecting private property on one part of the coast often contributes
to higher rates of erosion elsewhere, making one person's seawall another's woe.

International equity is another important issue. Low-lying developing
countries stand to lose the most from accelerated sea level rise yet can least
afford to build levees and dikes on a grand scale. These regions face
consequences grossly disproportionate to their relatively small contribution to
the greenhouse effect. At the same time, however, development projects now in
progress are putting enormous pressure on regional ecosystems, while aggravating
the current and likely consequences of sea level rise.

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Jacobson

GLOBAL CHANGES, LOCAL OUTCONES

Worldwide average sea level depends primarily on two variables. One, the
shape and size of ocean basins, involves geological changes over many millions
of years. The other, the amount of water in the oceans, is influenced by
climate, which can have a more rapid impact (Milliman, 1989; Titus, 1987a, 1989;
The Oceanography Report, 1985).

Ocean basins change their shape and size in a process similar to the buildup
of land recorded in stratified rock. The sea floor builds out from ocean ridges
via the accumulation of lava, which forms multiple layers. The weight of new
layers causes the earth's crust to settle and subside. If subsidence occurs more
rapidly than new volcanic rock is formed, the basin deepens and the water level
falls (assuming a constant volume of water). If the production of new rock
exceeds subsidence, on the other hand, the basin's volume decreases and the water
level rises (Milliman, 1989).

Seawater volume may change much more quickly than basin size and -shape.
A higher global average temperature can alter sea level in four ways. The
density can decrease through the warming and subsequent expansion of seawater,
which increases volume. The volume can also be raised by the melting of alpine
glaciers, by a net increase in water as the fringes of polar glaciers melt, or
by more ice being discharged from ice caps into the oceans.

Glaciers and ice shelves, such as those in Antarctica and Greenland, freeze
or melt in a cycle on the order of every 100,000 years. In the last interglacial
period, average temperatures were I degree Celsius warmer, and sea level was 6
meters (20 feet) higher. During the Wisconsin glaciation 18,000 years ago, the
most recent ice age, enough ocean water was collected in glaciers to drop the
sea off the northeastern U.S. coast 100 meters below its level today (Milliman
et al., 1989; Pirazzoli, 1985).

Globally and locally, sea level also fluctuates day to day and year to year
as a result of short-term meteorological and physical variables that may also
be affected by global warming. Tidal flows, barometric pressure, the actions
of wind and waves, storm patterns, and even the earth's rotational alignment all
influence sea level (Titus, 1987a; Barnett, 1983).

The slight variations in global climate of the last 5,000 years are
responsible for correspondingly small fluctuations in sea level. Over the past
100 years, however, global sea level rose 10-15 centimeters (4-6 inches), a
somewhat faster pace than the rate during the previous several thousand years.
Scientists continue to debate the cause of this rise; many argue that no evidence
yet indicates it is due to human-induced warming, while others are not so
sanguine (Milliman, 1989).

Faster global average sea level rise is not the only threat to coastal
areas, nor are changes in the earth's atmosphere the only consequences of human
activity likely to accelerate this trend. Discussions that focus only on global
averages mask important differences in relative, or local, sea level. Although

103

Problem Identification

the two are fundamentally different, global average sea level rise can be
compounded by local fluctuations in land elevation and geological processes, such
as tectonic uplift or subsidence in coastal areas. Local ratE!S of sea level rise
in turn depend in large part on the sum of the global pattern and local
subsidence.

Land subsidence is a key issue in the case of river deltas, such as the
Nile and Ganges, where human activities are interfering with the normal
geophysical processes that could balance the effects of rising water levels.
These low-lying regions, important from both ecological and social standpoints,
will be among the first lost to inundation under even slight rises in sea level.

Under natural conditions, deltas are in dynamic equilibrium, forming and
breaking down in a continuous pattern of accretion and subsidence. Subsidence
in deltas occurs naturally on local and regional scales through the compaction
of recently deposited riverborne sediments. As long as enough sediment reaches
.a delta to offset subsidence, the area either grows or maintains its size. The
Mississippi River delta, for example, was built up over time by sediments
deposited during floods and laid down by the river along its natural course to
the sea. If sediments are stopped along the way, continuing compaction and
erosion cause loss of land relative to the sea, even if the absolute level of
the sea remains unchanged.

Large-scale human interference in natural processes has had dramatic effects
both on relative rates of sea level rise and on coastal ecosystems in several
major deltas. Channeling, diverting, or damming rivers can greatly reduce the
amount of sediment that reaches a delta, as has happened in the Ganges, the
Mississippi, and most other major river systems, resulting in heavier shoreline
erosion and an increase in water levels. Furthermore, the mining of subterranean
stores of groundwater and of oil and gas deposits can raise subsidence rates.
In Bangkok, local subsidence has reached 13 centimeters per year, as the water
table has dropped because of excessive withdrawals of groundwater over the past
three decades (Salinas et al., 1986; Milliman, 1988).

These factors can dramatically affect the local outcome! of global changes.
Subsidence can result in a local sea level rise in some delta regions that is
up to five times that of a global mean increase. Under a 20-centimeter worldwide
average increase, for example, local sea level rise may range from 33 centimeters
along the Atlantic and gulf coasts of the United States to one meter in rapidly
subsiding areas of Louisiana and in parts of California and Texas. As the rate
of global rise accelerates, the rise in local sea level on rapidly subsiding
coasts will multiply severalfold (Sestini et al., 1989; Titus, 1989).

Uncertainties abound on the pace of all the possible changes expected from
global warming. The most immediate effect will probably be an increase in volume
through thermal expansion. The rate of thermal expansion depends on how quickly
ocean volume responds to rising atmospheric temperatures, how fast surface layers
warm, and how rapidly the warming reaches deeper water masses. The pace of
glacial melt and the exact responses of large masses such as the antarctic shelf
are equally unclear. Over the long term, however, glaciers and ice caps will

104

Jacobson

make the largest contribution to increased volume if a full-scale global warming
occurs. (Mel t i ng of the Arct i c Ocean i ce pack woul d have no ef fect on sea 1 evel ,
since the ice is floating, displacing an amount of water roughly equal to that
in the submerged ice) (Titus, 1989).

Over the past five years, a number of scientists have estimated the possible
range of greenhouse- induced sea level rise by 2100. Gordon de Q. Robin projects
an increase of anywhere from 20 to 165 centimeters. Computations by other
scientists yield projections as high as 2-4 meters over the next 110 years.
Widely cited EPA estimates of global average sea level rise by 2100 range from
50 to 200 centimeters (1.6 to 6.5 feet), depending on various assumptions about
the rate of climate change. The discussion in this chapter uses the EPA figures
unless otherwise noted. Most models do agree that initial rates of increase will
be small relative to the much more rapid acceleration expected after 2050.
After 2100, the rate is anybody's guess. In any case, even the low range of
estimates portends a marked increase over the current global pace (Robin, 1986;
Titus, 1989).

If global warming runs its course unabated, resulting in average
temperatures toward the higher end of the range, the earth may eventually be
awash in seawater. In theory, the world's total remaining ice cover contains
enough water to raise sea level over 70 meters. Some early reports, taking this
fact to its extreme, predicted changes of similar magnitude within a brief period
of time. But such an increase is more science fiction than fact, since complete
melting of all ice packs would take several thousand years (Henderson -Sell ers
and McGuffie, 1986).

What is important about the sea level rise expected from global warming is
the pace of change. The rate expected in the foreseeable future -- one meter
by 2075 is certainly plausible -- is unprecedented on a human time scale. Higher
rates of global increase mean more rapid relative rise where subsidence is
excessive. Unfortunately, with today's level of population and investment in
coastal areas, the world has much more to lose from sea level rise than ever
before.

LANDS AND PEOPLES AT RISK

From the atmosphere to the ocean, humans are proving themselves to be
forceful -- if unintentional -- agents of change. By and large, the costs of
higher seas tomorrow will be determined by patterns of development prevalent in
river systems and coastal areas today. Intense population pressures and economic
demands are already taking their toll on deltas, shores, and barrier islands.
Rapid rates of subsidence and coastal erosion ensure that many areas of the world
will experience a one-meter increase in sea level well before a global average
change of the same magnitude. As a result, countless billions of dollars worth
of property in coastal towns, cities, and ports will be threatened, and problems
with natural and artificial drainage, saltwater intrusion into rivers and
aquifers, and severe erosion of beaches will become commonplace.

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Prob7em Identification

The ebb and flow of higher tides will cause dramatic declines in a wide
variety of coastal ecosystems. Wetlands and coastal forests, which account for
most of the world's land area less than a meter above the mean, are universally
at risk. Loss of coastal wetlands in Louisiana today provides a good case study
for the future.

Deterioration of the Mississippi River delta began early in the nineteenth
century, shortly after levees (embankments to prevent flooding) became
extensively used. Subsidence and land loss accelerated after 1940 with an
increase in river diversions and the tapping of fossil fuel and groundwater
deposits. Combined with sea level rise, these processes are now drowning
Louisiana's coastal marshes at rates as high as 130 square kilometers per year,
giving that state the dubious distinction of losing more land to the sea on an
annual basis than any other region in the world (Salinas et al., 1986).

Coastal swamps and marshes are areas of prodigious biological productivity.
Louisiana's marshes, for example, cover 3.2 million hectares and constitute 41
percent of all wetlands in the United States. The region supplies 25 percent
of the U.S. seafood catch and supports a U.S. $500-million-a-year recreational
industry devoted to fishing, hunting, and birding. The ecological benefits
derived from these same wetlands are inestimable. Nearly two-thirds of the
migratory birds using the Mississippi flyway make essential use of this
ecosystem, while existing marshlands and barrier islands buffer inland areas
against devastating hurricane surges. Marshes not only hold back the intrusion
of the Gulf of Mexico's saltwater into local rivers and aquifers, but they are
also a major source of freshwater for coastal communities, agriculture, and
industry (Hawxhurst, 1987).

What was 1 ai d down over mi 11 i ons of years by the sl ow depos i t of s i 1 t washed
off the land from the Rockies to the Appalachians may disappear in little over
a century. The combination of global sea level rise subsidence could overrun
Louisiana's famous bayous and marshland by 2040, by allowing the Gulf of Mexico
to surge some 53 kilometers (33 miles) inland. With the delicate coastal marsh
ecology upset, fish and wildlife harvests would decline precipitously, and a
ripple effect would flatten the coastal economy. Communities, water supplies,
and infrastructure would all be threatened. Most of these trends are already
apparent in Louisiana and are becoming evident in other parts of the United
States (Salinas et al., 1986; Hawxhurst, 1987).

According to EPA estimates, erosion, inundation, and saltwater intrusion
could reduce the area of U.S. coastal wetlands up to 80 percent if current
projections of future global average sea level are realized. Not only the
Mississippi Delta, but the Chesapeake Bay and other vital wetland regions would
be irreparably damaged. Dredged, drained, and filled, coastal wetlands in the
United States are already under siege from land and sea. Were it not for the
enormous pressure that human encroachment puts on them, these swamps and marshes
might have a chance to handle rising seas by reestablishing upland. But heavy
development of beach resorts and other coastal areas throughout the country means
that few wetlands have leeway to "migrate" (Titus, 1987b).

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Jacobson

The extent of wetland loss will depend on the degree to which coastal towns
and villages seek to protect beachfront property under different scenarios of
sea level rise. An analysis by the U.S. EPA showed that some 46 percent of all
U.S. wetlands would be lost under a one-meter rise (from global sea level rise
and local subsidence) if shorelines were allowed to retreat naturally. Building
bulkheads and levees that block the path of wetland migration would entail higher
losses. Fully 66 percent of the U.S. wetlands would be lost if all shorelines
were protected. If only currently developed mainland areas and barrier islands
were protected, the loss could be kept to 49 percent. Loss of up to 80 percent
of the country's wetlands is envisioned under a more rapid rate of rise (Titus,
1987b).

In any case, there will be severe reductions in food and habitat for birds
and juvenile fish. No one has yet calculated the immense economic and ecological
costs of such a loss for the United States, much less extrapolated them to the
global level. Yet as global average sea level rises, these problems will surely
become more severe and widespread in ecosystems around the world.

A one-meter rise in sea level would wipe out much of England's sandy
beaches, salty marshes, and mud flats, according to a 1989 study by the Natural
Environment Research Council in London, for example. The most vulnerable areas
lie in the eastern part of the country, including the low-lying fens and marshes
of Essex and north Kent. More than half of Europe's wading birds winter in
British estuaries, and they are destined to lose this vital habitat (Boorman et
al., 1989).

Highly productive mangrove forests throughout the world will also be lost
to the rising tide. Mangroves are the predominant type of vegetation on the
deltas along the Atlantic coast of South America. On the north coast of Brazil,
active shoreline retreat is less of a problem because little human settlement
exists; the mangroves may be able to adapt. In the south, however, once-
extensive mangroves have already been depleted or hemmed in by urban growth,
especially near Rio de Janeiro. No more than 100 square kilometers of mangroves
remain where thousands once stood. As sea level rises, these remaining areas
will disappear too (Bird, 1986).

Eric Bird of the University of Melbourne in Australia notes that mangrove-
fringed coastlines have become much less extensive in Australia, Africa, and Asia
in recent decades as a result of fishpond construction and land reclamation for
mining, settlement, and waste disposal. Where they remain, mangroves stand on
the frontlines between salt marshes and freshwater vegetation. Bird argues that
submergence will kill off large areas of the seaward mangroves, especially where
human developments abutting mangrove forests prevent their landward retreat.
In Asia, for example, the land behind mangroves is often intensively used for
fishponds or rice fields. Thus, as sea level rises, it will threaten not only
the mangrove species that cannot reestablish upland, but also the economic value
of products derived from rice fields and brackish-water fishponds within the
flood zone (Bird, 1986).

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Problem Identification

In the Bight of Bangkok, the mangrove fringe has alroady largely been
cleared and converted into fish and shrimp ponds and salt pans. Landward canals
have been built to irrigate rice fields. A one-meter sea level rise would
threaten to submerge all existing mangroves and an additional zone up to 300
meters landward, wiping out the fish farms. This is likely to happen on the
southwestern coast of Bangladesh as well, where 6,000 square kilometers of
mangroves, locally known as "sunderbans," are at risk. A maze of heavily
forested waterways that is both economically and ecologically valuable, this area
shields the heavily settled region behind it from the sea (Broadus et al., 1986).

Worldwide, erosion of coastlines, beaches, and barrier islands has
accel erated over the past 10 years as a resul t of ri s i ng sea. 1 evel . A survey
by a commission of the International Geophysical Union demonstrated that erosion
had become prevalent on the world's sandy coastlines, at least 70 percent of
which have retreated during the past few decades (Bird, 1987, 1990; Dean, 1989).

Changes on beaches vary with the amount of sand supplied to and lost from
the shore as a result of wave activity. The U.S. Army Corps of Engineers found
that of the 134,984 kilometers of American coastline, 24 percent could be
classified as "seriously" eroding. Over the past 100 Years the Atlantic
coastline has eroded an average of 60-90 centimeters (2-3 feet) a year; on the
gulf coast, the figure is 120-150 centimeters. Relatively, few of the most
intensively developed resorts along the U.S. coast have beaches wider than about
30 meters at high tide. Projections of sea level rise over the next 40-50 years
suggest that most recreational beaches in developed areas could be eliminated
unless preventive measures are taken (Titus, 1987a).

Increased erosion would decrease natural storm barriers. Coastal floods
associated with storm surges surpass even earthquakes in loss of life and
property damage worldwide. Apart from greater erosion of the barrier islands
that safeguard mainland coasts, higher seas will increase flooding and storm
damage in coastal areas because raised water levels would provide storm surges
with a higher base to build upon. And the higher seas would decrease natural
and artificial drainage (Murty et al., 1988; Titus, 1987a).

A one-meter sea level rise could turn a moderate storm into a catastrophic
one. A storm of a severity that now occurs on average every 15 years, for
example, could flood many areas that are today affected only by truly massive
storms once a century. Oceanographer T.S. Murty states that as cultivation and
habitation of newly formed low-lying delta land continues, "even greater storm
surge disasters must be anticipated" (Murty et al., 1985).

Murty's study shows that losses are nowhere more serious than in the Bay
of Bengal. About 60 percent of all deaths due to storm surges worldwide in this
century have occurred in the low-lying agricultural areas of the countries
bordering this bay and the adjoining Andaman Sea. Murty puts the cost of damage
from storm surges in the Bay of Bengal region between 1945 and 1975 at U.S. $7
billion, but warns that this number "scarcely expresses the impact of such
disasters on developing countries" (Murty et al., 1988).

108

Jacobson

Bangladesh -- where storm surges now reach as far as 160 kilometers inland
-- accounts for 40 percent of this toll. In 1970, this century's worst storm
surge tore through the countryside, initially taking some 300,000 lives, drowning
millions of livestock, and destroying most of Bangladesh's fishing fleet. The
toll climbed higher in its aftermath. As the region's population mounts, so does
the potential for another disaster (Murty et al., 1988).

Studies indicate a dramatic increase in the area vulnerable to flooding in
the United States as well. A one-meter rise would boost the portion of
Charleston, South Carolina, now lying within the 10-year floodplain from 20 to
45 percent. A 1.5-meter rise would bring that figure to more than 60 percent,
the current area of the 100-year floodplain. Effectively, once-a-century floods
would then occur on the order of every 10 years. In Galveston, Texas, the 100-
year floodplain would move from 58 percent of the low-lying to 94 percent under
a rise of just 88 centimeters (Hoffman et al., 1983).

Sea level rise will also permanently affect freshwater supplies. Miami is
a case in point. The city's first settlements were built on what little high
ground could be found, but today most of greater Miami lies at or just above sea
level on swampland reclaimed from the Everglades. Water for its 3 mill ' ion
residents is drawn from the Biscayne aquifer, which flows right below the city
streets. That the city exists and prospers is due to what engineers call a
"hydrologic masterwork" of natural and artificial systems that hold back swamp
and sea (Miller et al., 1988).

Against a one-meter rise in ocean levels, Miami's only defense would be a
costly system of seawalls and dikes. But that might not be enough to spare it
from insidious assault. Freshwater floats atop saltwater, so as sea levels
rise, the water table would be pushed nearly a meter closer to the surface. The
elaborate pumping and drainage system that currently maintains the integrity of
the highly porous aquifer could be overwhelmed. The higher water table would
cause roads to buckle, bridge abutments to sink, and land to revert back to
swamp. Miami's experience would not be unique. Large cities around the world
-- Bangkok, New Orleans, New York, Taipei, and Venice, to name a few -- face
similar prospects.

A study by the Delaware River Basin Commission indicates that a rise of 13
centimeters by the end of this decade would pull the "salt front" on that river
from two to four kilometers further inland if there were a drought similar to
one in the 1960s that contaminated Philadelphia's water supply. A rise of I-
2.5 meters would push saltwater up to 40 kilometers inland under drought
conditions. The resulting contamination of freshwater would exceed New Jersey's
health-based sodium standard 15 to 50 percent of the time (Titus, 1987a).

Countries bordering the Mediterranean would suffer significant economic
losses. Greece and Italy, for example, face threats to their tourism industries
and to specialized agricultural industries, as well as to important harbors.
A 1989 UNEP report points out that, though they make up only 17 percent of the
total land area of the Mediterranean region, the alluvial and coastal plains of
most countries bordering this sea "have [considerable] demographic and economic

109

Problem Identification

importance." The coast is home to 37 percent of the region's population, some
133 million people. The report cautions that, while serious environmental
problems -- from water pollution and salinization to shoreline erosion and loss
of habitat -- already exist in the region, owing to agricultural and industrial
practices, tourism, and urbanization, "sea level rise will considerably affect
the economy and well-being of many countries, especially because many low coasts
will increasingly experience physical instability" resulting from subsidence and
reduced sedimentation (Sestini et al., 1989).

MOST VULNERABLE, LEAST RESPONSIBLE

Social, economic, and environmental costs of sea level rise will be highest
in countries where deltas are extensive, densely populated, and extremely food-
productive. In these countries, most of which are in the Third World, heavy
reliance on groundwater and the completed or proposed damming and diversion of
1 arge ri vers - - for i ncreased hydropower and agri cul tural use, for f 1 ood control ,
and for transportation -- have already begun to compound problems with sea level
rise. Almost without exception, the prognosis for these vulnerable low-lying
countries in a greenhouse world is grim.

The stakes are particularly high throughout Asia, where damming and
diversion of river systems such as the Indus, Ganges -Brahmaputra, and Yellow
Rivers has greatly decreased the amount of sediment getting to deltas. The
sediments feeding Asia's many great river deltas account for at least 70 percent
of the total that reaches oceans, and they replenish agricultural land with the
fertile silt responsible for a large share of food produced in those nations
(Milliman, 1988).

As elsewhere, the deltas reliant on these sediments support sizable human
and wildlife populations while creating protective barriers between inland areas
and the sea. Large cities, including Bangkok, Calcutta, Dacca, Hanoi, Karachi,
and Shanghai, have grown up on the low-lying river banks. These heavily
populated areas are almost certain to be flooded as sea level rise accelerates
(Milliman et al., 1988; Devoy, 1987; Broadus et al., 1986).

The United Nations Environment Programme's 1989 global survey represents
the first attempt to analyze systematically the regions most vulnerable to sea
level rise. An overall lack of data posed severe constraints on the assessments
of potential impacts. In defining "vulnerability," for example, UNEP sought. to
evaluate population densities for the total area worldwide lying between 1.5 and
5 meters above mean sea level. At the global level, however, detailed
topographic maps are not available for such low elevations (UNEP, 1989).

On a country - by- country basis, four main criteria were used to determine
vulnerability. The first two -- the share of total land area between zero and
five meters above mean sea level and the density of coastal populations -- were
used to assess the likely demographic impacts. Identified as most vulnerable
were areas where coastal population density exceeded 100 people per square
kilometer.

110

Jacobson

Potential economic and ecological losses were gauged by the other two
criteria: the extent of agricultural and of biological productivity within low-
lying areas. First, UNEP isolated countries where lowland agricultural
productivity grew on average more than 2 percent a year between 1980 and 1985.
Second, it added the regions with the largest inventories of coastal wetlands
and tidal mangrove forests.

Under these guidelines, 10 countries -- Bangladesh, Egypt, Indonesia, the
Maldives, Mozambique, Pakistan, Senegal, Surinam, Thailand, and The Gambia --
were identified as "most vulnerable." These 10 share many characteristics,
including the fact that they are, by and large, poor and populous (see Table 1).
Not insignificantly, as a group they also contribute relatively little to the
current buildup of greenhouse gases.

UNEP identified both primary and secondary impact areas as important in
each of these countries. The primary impact area consists of the coastal region
between zero and 1.5 meters elevation, which would be completely lost under a
1.5-meter rise. The secondary area (1.5-3.0 meters above today's mean) is
vulnerable not only to a rise in seas of equivalent measures but also to the many
pressures -- such as an influx of environmental refugees, and increased regional
demand for food, housing, and other resources -- that would arise from inundation
of the land closer to the sea (UNEP, 1989).

Table 1. Ten Countries Most Vulnerable to Sea Level Rise

Per Capita
Countries Population Income
(millions) (U.S. dollars)

Bangladesh 114.7 160
Egypt 54.8 710
Indonesia 184.6 450
Maldives 0.2 300
Mozambique 15.2 150

Pakistan 110.4 350
Senegal 5.2 510
Surinam 0.4 2,360
Thailand 55.6 840
The Gambia 0.8 220

Sources: United Nations Environment Programme, Criteria for Assessing
Vulnerability to Sea-Level Rise: A Global Inventory to High Risk Areas (Delft,
The Netherlands: Delft Hydraulics, 1989); income and population data from
Population Reference Bureau, 1989 World Population Data Sheet, Washington, D.C.,
1989.

ill

Problem Identification

Detailed information on the land area, population, and economic output
likely to be affected by a rise of up to three meters was unattainable for all
but Bangladesh and Egypt. For data on these two countries, UNEP drew on a 1988
study by John Milliman and his colleagues at the Woods Hole Oceanographic
Institute in Massachusetts. Their study showed the combined effects of sea level
rise and subsidence on the Bengal and Nile delta regions, where the homes and
livelihoods of some 46 million people are potentially threatened (Milliman et
al., 1988).

Bangladesh

The river delta nations of the Indian subcontinent and southeast Asia depend
heavily on ocean resources and coastal areas for transportation, mariculture,
and habitable land. Bangladesh is no exception. The Bengal delta, the world's
largest such coastal plain, accounts for 80 percent of Bangladesh's land mass
and extends some 650 kilometers from the western boundary with India to the
Chittagong hill tracts. Milliman observes that because the delta is so close
to the sea (most of the area is only a meter or two above that level now), an
increase in sea level rise accompanied by higher rates of coastal storm erosion
is likely to have a greater effect here than on any other delta in the world
(Milliman, 1988; Broadus et al., 1986).

Residents of one of the poorest and most densely populated nations in the
world, Bangladeshis already live at the margin of survival. Most people depend
heavily on the agricultural and economic output derived from land close to the
sea and currently subject to annual floods from both rivers and ocean storm
surges. Subsidence is already a problem in this region. The Woods Hole study
indicates that as global warming sets in, relative sea level rise in the Bengal
delta may well exceed two meters by 2050. Because half the country lies at
elevations below five meters, losses to accelerated sea level rise will be high
(Milliman et al., 1988; for a further discussion of environmental refugees see
Jacobson, 1988).

UNEP estimates based on current population size and density show that 15
percent of the nation's land area, inhabited by 15 million people, is threatened
by total inundation from a primary rise of up to 1.5 meters. Secondary increases
of up to three meters would wipe out over 28,500 square kilometers, displacing
an additional 8 million people. These projections do not account for the ongoing
increase in Bangladesh's population or for continuing settlement of the delta
area. Thus, they clearly understate the potential number of environmental
refugees (UNEP, 1989).

By the end of the next century, Bangladesh as it is known today may
virtually have ceased to exist. Pressures to develop agriculture have quickened
the pace of damming and channeling on the three giant rivers -- the Brahmaputra,
the Ganges, and the Meghna -- that feed the delta. As a result, sediment flow
is being dramatically reduced and subsidence is increasing.

This situation is being aggravated by the increasing withdrawal of
groundwater. Milliman of Woods Hole notes a sixfold increase in the number of

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Jacobson

wells drilled in the country between 1978 and 1985, raising subsidence to perhaps
twice the natural rate. The researchers concluded that interference in the delta
ecosystem today may make a far larger area and population susceptible to sea
level rise, causing dislocation of more than 40 million people (Milliman et al,
1988).

Egypt

Egypt -- almost completely desert except for the thin ribbon of productive
land along the Nile and its delta -- can ill afford the likely costs of sea level
rise. The country's millions crowd on to the less than 4 percent of the land
that is arable, leading to a population density in the settled area of Egypt of
1,800 people per square kilometer (Milliman et al., 1988).

In the Nile delta, extending from just west of the port city of Alexandria
to east of Port Said at the northern entrance of the Suez Canal, local sea level
rise already far exceeds the global average because of high rates of subsidence.
The construction of the first barrages or dams on the Nile in the 1880s cut
massively the amount of sediments that nourished the delta. This situation was
exacerbated by the building of the Aswan Dam in 1902 and its enlargement in 1934.
Extensive diversion of water for irrigation-and land reclamation projects since
then has closed down a number of the Nile's former tributaries, greatly reducing
the river's outward flow (Broadus et al., 1986).

Even so, approximately 80-100 million tons of sediment were delivered
annually to the Nile delta until 1964, when the closure of the Aswan Dam
virtually eliminated the silt getting through. High rates of relative sea level
rise and the accompanying acceleration in subsidence and erosion have resulted
in a frightening rate of coastal retreat, reaching 200 meters annually in some
places (Broadus et al., 1986).

Milliman's study suggests that local sea level rise will range from 1.0 to
1.5 meters by 2050, rendering up to 19 percent of Egypt's already scarce
habitable land unlivable. By 2100, an expected rise of between 2.5 and 3.3
meters may drown 26 percent of the habitable land -- home to 24 percent of the
population and the source of an equal share of the country's economic output
(Milliman et al., 1988).

To feed a population growing nearly 3 percent annually, the government has
followed a strategy of.land reclamation and development of lagoon fisheries on
the delta banks. The principal existing natural defenses against transgression
by the sea are a series of dunes and the freshwater (but increasingly brackish)
lakes that fall behind them. According to James Broadus of Woods Hole, these
lakes -- Burullos, Idku, Manzalah, and Maryut -- are the major source of the
nation's approximately 100,000 tons of annual fish catch, 80 percent of which
are freshwater fish. Ironically, the lakes and surrounding areas now slated for
development in the regions of Port Said and Lake Maryut will most likely be
inundated some time in the next century (Broadus et al., 1986).

113

Problem Identification

Unless steps are taken now to slow sea level rise, Egyptians can also look
forward to damage to ports and harbors, increasing stress on freshwater supplies
due to saline encroachment, and the loss of beaches that support tourism, such
as those in Alexandria.

Extending these scenarios of Bangladesh and Egypt to the eight other most
endangered nations presents a sobering picture. Despite the lack of data,
preliminary findings show the situation to be equally grave. In another study,
Milliman notes that when the impact of the global rise is added to that of
regional subsidence and of damming and diversion, Indian Ocean deltaic areas may
register a relative subsidence of at least several meters, 1E!ading to coastal
regression of several tens of kilometers by the twenty-second century (Milliman,
1988).

Indonesia

At least 40 percent of Indonesia's land surface is classified as vulnerable
to sea level rise. In terms of both size and diversity, the country is home to
one of the world's richest and most extensive series of wetlands. Here, too,
population pressures are already threatening these fragile ecosystems.
Transmigration programs have resettled millions of people in the past several
years from the overpopulated islands of Java and Bali to the tidal swamps of
Sumatra and Kalimantan, a policy decision that may be much regretted when these
lands give way to the sea. Although studies remain to be done on how many people
will eventually be affected by the ocean's incursion, the numbers are certain
to be high (Hekstra, 1989).

China

A one- to two-meter rise in sea level could be disastrous for the Chinese
economy as well. The Yangtze delta is one of China's most heavily farmed areas.
Damming and subsidence have contributed to a continuing loss of this valuable
land on the order of nearly 70 square kilometers per year since 1947. A sea
level rise of even one meter could sweep away large areas of the delta, causing
a devastating loss in agricultural productivity in China (Broadus et al., 1986).

PAYING BY THE METER

China's 2,400-kilometer-long Great Wall is considered the largest
construction project ever carried out, but it may soon be superseded in several,
countries by modern-day analogues: great seawalls. Assuming a long-run increase
in rates of global average sea level rise, societies will have to choose some
adaptive strategies. Broadly speaking, they face two choices: fight or flight.
Many governments see no alternative to building jetties, seawalls, groins, and
bulkheads to hold back the sea. Yet the multibillion-dollar price tags attached
to these may be higher than even some well-to-do countries can afford, especially
when accounting for the long-term ecological damage such structures can cause.

114

Jacobson

Along with the intensified settlement of coastal areas worldwide over the
past century has come a belief that, as coastal geologist Orrin Pilkey and his
colleagues put it, "human ingenuity could tame any natural force," protecting
human settlements from the forces of climate and the oceans. Conseuently,
people have been inclined to build closer and closer to the ocean, investing
billions of dollars in homes and seaside resorts and responding to danger by
confrontation (Anonymous, 1985).

Nowhere in the world is the battle against the sea more actively engaged
than in the Netherlands. Hundreds of kilometers of carefully maintained dikes
and natural dunes keep the part of the country that is now well below sea level
-- more than half the total -- from being flooded. As Dutch engineers know, the
ocean doesn't relinuish land easily. In early 1953, a storm surge that hit the
delta region caused an unprecedented disaster. More than 160 kilometers of dikes
were breached, leading to the inundation of 1,000 suare kilometers of land and
more than 1,800 deaths. In response, the government put together the Delta Plan,
a massive public works project that took two decades and the euivalent of 6
percent of the country's gross national product each year until finally completed
in 1986 (Goemans and Vellinga, 1987; UNEP, 1988).
The Dutch continue to spend heavily to keep their extensive system of dikes
and pumps in shape, and are now protected against storms up to those With a
probability of occurring once in 10,000 years. But the prospect of accelerated
sea level rise implies that maintaining this level of safety may reuire
additional investments of up to U.S. $10 billion by 2040 (Goemans and Vellinga,
1987; UNEP, 1988).

Although these expenditures are large, they are trivial compared with what
the United States, with more than 30,000 kilometers (19,000 miles) of coastline,
would have to spend to protect Cape Cod, Long Island, North Carolina's Outer
Banks, most of Florida, the Bayous of Louisiana, the Texas gulf coast, the San
Francisco Bay area, and the Maryland, Massachusetts, and New Jersey shores (The
Times Atlas of the World, 1985).

Preliminary EPA estimates of the total bill for holding the sea back from
U.S. shores -- including costs to build bulkheads and levees, raise barrier
islands, and pump sand, but not including the money needed For replacing or
repairing infrastructure such as roads, sewers, water mains, and buried cables
-- range from U.S. $32 to U.S. $309 billion for a one z cne-hz'!',F 'L-@,jc-meter rise in
sea I evel . (A one-meter rise would cost U.S. $/3 `4X @.S. $111 billion.)
Extending the projections to impoverished coas`Call. areas of Africa, Asia, and
South America underscores the futility of s8L4cl4c an 8appro4a12d4@ 4ind4er a scenario of
rapidly rising seas (Titus, 1989).

Nevertheless, in most industrial countries at least, property owners in
coastal areas have become a powerful interest group supportive of defenses that
will save their land, even if only for the short term. Many countries have made
vast investments reclaiming land from the sea for us-, by -."4arge coastal
populations: witness the efforts in Singapore, Hong Kong, and Tokyo. In most
cases, governments have encouraged and continued to support, -L-0his constituency.

1165

Prob7em Identification

Heavy investments in roads, sewers, and other public services and insurance
against disasters have largely been subsidized by taxpayers living far from any
coast.

Political pressures to maintain these lands through dikes, dams, and the
like will be high. "The manner in which societies respond to the impact of
rising sea levels," observes G.P. Hekstra, "will be determined by a mix of
conditions [including] the vested interests that are threatened, the availability
of finance ... employment opportunities, political responsibilities and national
prestige." Eric Bird of Australia argues, for example, that state capitals and
other seaside towns there and resorts in Africa and Asia will probably be
maintained by beach nourishment programs -- literally "feeding" the beach with
sand transported from elsewhere -- no matter the cost (Hekstra, 1989; Bird,
1986).

Political support for subsidizing coastal areas may be undercut by competing
fiscal demands over the long run. In the United States, where a burgeoning
budget deficit has vastly reduced expenditures on repairs and construction of
bridges and roads, for example, the Federal Highway Administration estimates that
bringing the nation's highway system up to "minimum engineering standards" would
cost a mind-boggling U.S. $565 to U.S. $655 billion over the next 20 years.
Today, that agency's budget is a meager U.S. $13 billion, and fiscal paralysis
keeps it from growing any larger. With increasing competition for scarce tax
dollars, property owners in the year 2050 may find the general public reluctant
to foot the bill for seawalls (Yoo, 1989).

Moreover, what may seem like protection often turns out to be only a
temporary palliative. While concrete structures may divert the ocean's energies
from one beach, they usually displace it onto another. And by changing the
dynamics of coastal currents and sediment flow, these hard structures interrupt
the natural processes that allow wetlands and beaches to reestablish upland,
causing them to deteriorate and in many cases disappear (Pilkey and Wright, 1989;
Dean, 1988).

Beach nourishment is a relatively benign defensive strategy that can work
in some cases. Comparing the costs and benefits illustrates that it is not
usually as prohibitively expensive as other approaches. Sand or beach
nourishment, for example, can cost U.S. $1 million per mile (U.S. $500,000 per
kilometer), but these costs are often justified by economic and recreational use
of the areas. A recent study of Ocean City, Maryland, found it would cost about
25@ per visitor to rebuild beaches to cope with a 30-centimeter rise, less than
1 percent of the average cost of a trip to the beach. A more rapid rate of sea
level rise would, of course, raise the ante. The fact remains that most beach
replenishment is temporary at best, indicating the need for continuous investment
(Pilkey and Wright, 1989; Dean, 1988).

Advocates of coastal environmental protection strategies argu .e convincingly
that coastal development should be limited. M'ost assert, -for example, that
future disasters may be prevented or the harm done by them lessened if highly
vulnerable areas were protected. In recent years, the tide of public opinion

116

Jacobson

in several states regarding conserving wetlands has tended to support the view
that some property should be allowed to return to its natural state, although
attitudes may changes as today's property owners face becoming tomorrow's
proprietors of marshes and bogs.

The legal definitions of private property and of who is responsible for
compensation in the event of natural disasters are already coming into question.
As sea level rise accelerates, pushing up the costs of adaptation, these issues
will most likely become part of an increasingly acrimonious debate over property
rights and individual interests versus those of society at large.

Enforcement of the coastal protection law in South Carolina in the aftermath
of the recent Hurricane Hugo is a good example of the types of conflicts that
can arise. On September 21, 1989, Hurricane Hugo came ashore at Charleston one
day after it ravaged several islands in the Caribbean. The storm, creating an
ocean surge that reached 20 feet at its highest point, killed 29 people on the
mainland and caused an estimated U.S. $4 billion worth of damage in the United
States. It also sparked a controversy over South Carolina's new beachfront
protection law. The statute completely prohibits any new seawalls from being
built and regulates commercial and residential construction in a setback area
along the coast. Because the storm ate up so much of the existing beach, 159
plots of land, on which houses were destroyed, all became part of the "dead zone"
where new buildings are prohibited. Several homeowners have filed suit against
the state for "taking property without just compensation." The States of Maine,
Maryland, North Carolina, and Texas also have enacted coastal protection laws
(see Klarin and Hershman, this volume; Smith, 1989; Griffiths, 1989; Titus,
1989).

Site-specific studies of several towns in the United States suggest that
incorporating projections of sea level rise into land-use planning can save money
in the long run. Projections of costs in Charleston, South Carolina, show that
a strategy that fails to anticipate and plan for the greenhouse world can be
expensive. Depending on the zoning and development policies followed, including
the amount of land lost and the costs of protective structures built, the costs
of a three-meter sea level rise would exceed U.S. $1.9 billion by 2075 -- an
amount equal to 26 percent of total current economic activity in this area. If
land-use policies and building codes are modified to anticipate rising sea
levels, this figure could be reduced by more than 60 percent. Similar studies
of Galveston, Texas, show that economic impacts could be lowered from U.S. $965
to U.S. $550 million through advanced planning (Titus, 1987a).

Obviously, heavily developed areas, such as the island of Manhattan, much
of which is less than two meters above high tide, will not be left to be
swallowed by the sea. An accounting method is needed to establish priorities
and assess the costs and benefits of protection strategies versus the costs of
inundation. Several analysts are attempting to develop such a model . Gary Yohe,
an economist at Wesleyan University in Connecticut, is developing a method of
comparing the costs of not holding back the sea with those of protecting coasts
on a year-to-year basis. His economic model is a first step toward "measuring
the current value of real sources of ... wealth that might be threatened ... if

117

Problem Identification

a decision to forego any protection from rising seas were made." In his
preliminary analysis, using Long Beach Island, New Jersey, as a case study, Yohe
focuses on estimating the market price of threatened structures, the worth of
threatened property, and the social value of threatened coastline.

A truly representative model should account for all the! costs and benefits
-- economic, ecological, and social -- of protection against other options. One
cost not explored in Yohels assessment is the loss in coastal ecological wealth
as a side effect of protection. In keeping with the figUres for the United
States as a whole, for example, researchers have estimated that a 1.5-meter rise
would eliminate about 80 percent of Charleston's wetlands with current barriers
in place. If additional developed areas are protected by bulkheads and levees,
a 90 percent loss is envisioned. The South Carolina beachfront protection law
seeks to prevent this large-scale destruction, but its political viability is
still in question (Titus, 1987a).

Protecti rig wetl ands requi res a trade-of f as wel 1 . Taki rig shore and wetl and
conservation measures basically implies a willingness to relinquish to the sea
some land area now in use or potentially available for social activities, such
as farming and home building. A study of coastal land loss in Massachusetts by
Graham Giese and David Aubrey of Woods Hole Oceanographic Institution illustrates
these processes and estimates the amount of land likely to be lost in
Massachusetts under three scenarios (Giese and Aubrey, 1987, 1989).

Giese and Aubrey distinguish between upland (relatively dry terrain that
is landward of wetland and not altered much by waves and tides), and wetland
itself, including coastal bluffs, dunes, beaches, and marshes that are affected
by these forces. Wetlands replace uplands as they migrate landward, resulting
in loss of total upland area. Where wetlands are protected by law (as they are
in Massachusetts) against being drained or filled, they gain at the expense of
uplands, essentially protecting the ecological over the purely economic value
of the land (Geise and Aubrey, 1987, 1989).

Relative sea level in Massachusetts has been rising some three millimeters
annually since 1950. Under the first scenario in Giese and Aubrey's study, which
assumes a continuation of current trends from 1980 through 2025, the sea along
Massachusetts' coasts would rise 36 centimeters. The state would therefore lose
0.23 square kilometers a year, or nearly 12 square kilometers over that period.
The second scenario assumes a higher global average rise by 2025 (EPA's low to
mid-range estimate), which when combined with subsidence leads to a total land
loss in Massachusetts of some 30 square kilometers by 2025. Finally, the third
case, assuming a rise of 48 centimeters, costs Massachusetts nearly 42 square
kilometers of upland, or commercially usable, area (Geise and Aubrey, 1987,
1989).

Whatever the strategy, industrial countries are in a far better financial
position to react than are developing nations. Bangladesh, for example, cannot
afford to match the Dutch kilometer for kilometer in seawalls. But its danger
is no less real. Debates over land loss may be a moot point in poorer countries
like Bangladesh, where evacuation and abandonment of coastal land may be the only

118

Jacobson

option when submergence and erosion take their toll and when soil and water
salinity increase. As millions of people displaced by rising seas move inland,
competition with those already living there for scarce food, water, and land may
spur regional clashes. Ongoing land tenure and equity disputes within countries
will worsen. Existing international tensions, such as those between Bangladesh
and its large neighbor to the west, India, are likely to heighten as the trickle
of environmental refugees from the nation that is awash becomes a torrent.

PLANNING AHEAD

The threats posed by rapidly increasing sea level raise questions that
governments and individuals must grapple with today. If the world moves quickly
onto a sustainable path, the effects of global warming and sea level rise can
be mitigated. Minimizing the impacts of climate change will reqllire that a
number of strategies be put in place right away. An unprecedented level of
international cooperation on agricultural, energy, forestry, and land-use
policies will be required. Most important, perhaps, is to develop a method for
comparing the costs of measures to avert global warming and its consequences
against the costs of adaptation. But for now, preparing to experience some
degree of global and regional changes in sea level is a rational response.

How can the world move away from the seemingly universal human tendency to
react in the face of disaster but to ignore cumulative, long-term developments?
An active public debate on coastal development policies is needed, extending from
the obvious issues of the here and now -- beach erosion, river damming and
diversion, subsidence, wetland loss -- to the uncertainties of how changes in
sea level in a greenhouse world will make matters far worse. Raising public
awareness on the forthcoming changes, developing assessments that account for
all future and present costs, and devising sustainable strategies based on those
costs are all essential.

Taking action now to safeguard coastal areas will have immediate benefits
while preventing losses from soaring higher in the event of an accelerated sea
level rise. Limiting coastal development is a first step, although strategies
to accomplish this will differ in every country. Governments may begin by
ensuring that private property owners bear more the costs of settling in coastal
areas. A more systematic assessment is needed of the value of creating dead
zones to be left in their natural state versus the economic and ecological costs
that ongoing development and the subsequent need for large-scale protection will
entail.

A new concept of property rights will have to be developed. Unbridled
development of rivers and settlement of v-ulnerable coasts and low-lying deltas
mean that more and more people and property will be exposed to land loss and
potential disasters arising from storm surges and the like. Governments that
plan over the long term to limit development of endangered coasts and deltas can
save not only money, but resources as well. Wherever wetlands and beaches are
not bordered by permanent structures, they will be able to migrate and

119

Problem Identification

reestablish farther upland, allowing society to reap the intangible ecological
benefits of biodiversity.

Of course, protection strategies will inevitably be carried out where the
value of capital investments outweighs other considerations. But again the key
is to plan ahead. As the Dutch discovered, more money can be slaved over the long
term if dikes and drainage systems are planned for before rattler than after sea
levels have risen considerably.

A reassessment of dam-building and river diversion projects in large deltas
could lead to a lessening of the ongoing destruction of wetland areas and prevent
further reductions in sedimentation, thereby minimizing subsidence as well. It
is unlikely that the damage done by large-scale dams, like the Aswan, can be
remedied. As with past projects, however, analyses of many dams now in the
pipeline do not reflect the often massive present and future environmental or
external costs. Better water management and increased irrigation efficiencies
can both increase crop yields and save water. Exploring the potential gains from
conservation may preclude the need for many more large-scale dams. The same can
be said of curtailing development of additional dams for hydropower by
encouraging energy efficiency and conservation.

Additional money is needed to do more research on sea level globally and
regionally. Funds are needed to support studies of beach and wetland dynamics,
as well as investigations of likely regional impacts; to take more frequent and
widespread measurements of global and regional sea level; and to design cost-
effective, environmentally benign methods of coping with coastal inundation.

The majority of developing nations most vulnerable to sea level rise can
do little about global warming independently. But they have a clear stake in
reducing pressures on coastal areas by taking immediate actions. Among the most
important of these is slowing population growth and, where necessary, changing
inequitable patterns of land tenure in interior regions that promote coastal
settlement of endangered areas. Furthermore, the governments of Bangladesh,
China, Egypt, India, and Indonesia, to name just a few, are currently promoting
river development projects that will harm delta ecosystems in the short term and
hasten the date they are lost permanently to rising seas.

The issue of how to share the costs of adaptation equitably may well be
among the hardest to resolve. Industrial countries are responsible for by far
the largest share of the greenhouse gases emitted into the atmosphere. And no
matter what strategies poorer nations adopt to deal with sea level rise, they
will need financial assistance to carry them out. Problems with coastal
protection, environmental refugees, changes in land and water allocation, and
a hose of other issues will plague poor coastal nations. The way industrial
countries come to terms with their own liability in the face of accelerated sea
level rise will play a significant role in the evolution of international
cooperation during the second half of the 21st century.

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Jacobson

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Yoo, J. 1989. Bad trip: as highways decay, their state becomes drag on
economy. Wall Street Journal, August 30.

123

ASSESSING THE IMPACTS OF CLIMATE:
THE ISSUE OF WINNERS AND LOSERS
IN A GLOBAL CLIMATE CHANGE CONTEXT

MICHAEL H. GLANTZ
Environmental and Societal Impacts Group
National Center for Atmospheric Research'
Boulder, Colorado

INTRODUCTION

Although most reviews of the greenhouse problem begin with the 1890s works
of Swedish scientist Arrhenius, the processes have been well known for more than
a century. Interest in the possible impacts on climate of CO, emissions have
waxed and waned since that time with interest reaching temporary peaks appearing
in the mid-1930s (Callendar, 1938), the mid-1950s (Revelle and Suess, 1957), and
again in the late 1970s (e.g., Kellog, 1977).

Today, we are inundated by assessments of the prospects of a global warming
and its possible impacts on society and the environment. Discussions of such a
prospect have steadily increased during the past fifteen years, reaching amazing
levels in the past year or so. In the United States, about three dozen bills
related to the global warming issue were submitted during the last congressional
session.

The century-long interest in this issue has been interrupted partly by other
more pressing and urgent historical events such as two World Wars, a worldwide
depression, decolonization, the Cold War, and a temporary global cooling; and
partly by the fact that the impacts of a temporary CO,-induced global warming
were originally believed to be beneficial to society. For example, Callendar
(1938) suggested that a greenhouse warming would help to thwart the emergence of
an apparently imminent ice age. Scientific evidence suggested that the Earth was
coming to the end of an interglacial period and that at any decade, the ice age
process could begin.

From about 1940 to the late 1960s, the Earth underwent an unexplained
cooling. Discussions in the scientific community about the possibility of a
global cooling were widespread. Scientists provided anecdotal (but nonetheless

'The National Center for Atmospheric Research is sponsored by the National
Science Foundation.

125

Prob7em Identification

convincing both to the lay public and segments of the scientific community)
evidence to support the belief that the Earth was possibly on the threshold of
an ice age: the growing season in England had been shortened by two weeks, fish
species formerly caught off the northern coast of Iceland began appearing only
off its southern coast; sea ice in the North Atlantic had increased in extent in
the early 1970s and was appearing in normally ice-free shipping lanes; and hay
production in Iceland had declined by 25% as a result of less hospitable weather.
In the United States, the fact that the armadillo, which had migrated as far
north as Kansas in warmer decades, was starting to retreat toward the south was
also used as evidence to support the ice age hypothesis. Geologic records were
invoked as well to show that an ice age was near.

During the brief period of concern regarding a global cooling, one issue
widely considered was how it might affect the relative economic and political
positions of different countries. Even the U.S. Central Intelligence Agency
undertook studi es to show how the cool i ng mi ght af fect the U. S. S. R. 's agri cul ture
(CIA, 1976). The Eco7ogist examined the potential impacts of a few degrees of
cooling on agriculture in the Canadian Prairies (Goldsmith, 1977).

Some books and articles on the topic went so far as to identify specific
countries that would become climate-related world powers in the event of a
cool i ng. , For exampl e, Ponte (1976) suggested that "adapti ng to a cool er cl imate
in the north latitudes, and to a drier climate nearer the equator, will require
vast resources and almost unlimited energy.... A few countries, such as
equatorial Brazil, Zaire, and Indonesia, could emerge as; climate-created
superpowers." He also suggested that "We can say with high probability today
that the global monsoon rainfall will be below average for the remainder of the
century."

Another book on the possibility of a global cooling (The Impact Team, 1977)
suggested that with a cooling "...there would be broad belts of excess and
deficit rainfall in the middle latitudes; more frequent failure of the monsoons
that dominate the Indian subcontinent, south China and western Africa; shorter
growing seasons for Canada, northern Russia, and north China. Europe could
expect to be cooler and wetter. Of the main grain-growing regions, only the
United States and Argentina would escape adverse effects." There was no
reluctance whatsoever to discuss who might win and who might lose or to identify
specific countries or specific economic sectors within a country as winners and
as losers.

A striking difference between the scientific and political responses in the
1970s (to a potential cooling) and those of today (to a warming) is that today
there is a strong opposition within scientific as well as policymaking circles
to recognize the existence of, let alone identify, specific winners and losers,
especially winners. U.S. Senator Albert Gore, for example, argues that there
will be no winners in the event of a global warming, a view that apparently is
also held by the U.S. EPA. Soviet scientist Mikhail Budyko, in contrast, asserts
that everyone will benefit from a global warming. Perhaps the comments that U.S.
Senator Tsongas made about diametrically opposing views on the energy crisis of
the 1970s and 1980s apply to Gore and Budyko: "Both of these approaches are

126

Glantz

equally absurd, equally rhetorical, and equally successful. When talking to the
convinced, they are very powerful. And that is basically how most people address
the issue: we are awash in rhetoric, not to mention hypocrisy, when what we need
is a careful sorting and weighing of the facts and values involved in making --
or not making -- a decision."

Many people believe discussing winners and losers will be divisive and
undermine efforts to put together a global coalition to combat global warming.
Opposition to the open recognition of winners and losers was recently highlighted
when Barber Conable, President of the World Bank, suggested in a speech that
there might be winners with a warmer atmosphere. Environmental groups, which
have been marching lock-step on this particular issue, opposed his public
comments. As a result of his speech, some U.S. Congressmen even suggested the
need for a closer scrutiny of the World Bank's activities and budget. For
example, The Washington Post (12 September 1989) reported, "In a letter to
Conable, Senator Kasten wrote, 'The bank's failure to be on the front lines of
efforts to fight global warming threatens the bank's long-term financial support
from Congress."'

A similar argument was raised with respect to preventive versus adaptive
strategies. When the U.S. EPA released two reports in 1983 suggesting that
global warming was inevitable (Seidel and Keyes, 1983) and, as a result, people
should plan for rising sea level (Hoffman et al., 1983), the Friends of the Earth
publication "Not Man Apart" denounced the Agency for "throwing in the towel,"
while at the same time, the President's science advisor denounced the reports as
"alarmist." There was a feeling that "premature" discussions about adaptive
strategies with respect to global warming would break down the development of a
united effort to support the enactment of preventive strategies. Proponents of
preventive strategies wanted attention to focus on prevention as the best way to
cope with global warming.

There is, however, one projected impact of global warming for which one is
allowed to identify specific winners and losers -- sea level rise. This is
probably because it is the one impact of a global warming for which there may be
no obvious winners at the national level. No one is reluctant to identify
specific losers associated with sea level rise (papers have identified winners
at the subnational level, such as coastal engineering firms and people who would
have beachfront property as a result of a neighbor's misfortune). In this
regard, one could argue that the sea level rise problem is similar to the
stratospheric ozone depletion problem -- no readily apparent national winners can
be identified. Such would probably not be the case for changes in rainfall
distribution, water resources availability, agricultural production, fisheries
productivity, and energy production and consumption.

In this paper, it is my intention to consider problems associated with the
process of labeling winners and losers. What factors, for e 'xample, must be taken
into account in labeling a region, an activity, or a country a winner or a loser?
How do perceptions compare with reality? Can wins and losses be objectively
identified? What are the costs and benefits of not addressing this issue as
opposed to addressing it openly?

127

Problem Identification

My intention is not to label specific countries as winners or losers. To
do that, one could simply use any of the GCM-generated scenarios, the scenarios
generated by paleoecological reconstructions, or assessments of recent
environmental changes and label specific countries and regions within countries
accordingly.

I realize that there is a risk associated with such an identification. If
winners and losers are identified with some degree of reliability, the potential
for unified action against the global warming will be reduced. Winners will not
necessarily want to relinquish any portion of their benefits to losers in order
to mitigate the impacts of their losses. On the other hand, there is also a risk
in not making such a distinction between winners and losers. While scientists
and policymakers formally discuss only losses associated with a global warming,
others may perce i ve that there wi 11 be pos i t i ve benef i ts as wel 1 . The resul t i s
that the proponents for action on global warming could be likened to the fable
about the emperor's new clothes, professing there are not winners, while everyone
agrees with them in public but privately believes the opposite. This could
sharply reduce the credibility of the proponents.

SCENARIOS OF WINNERS AND LOSERS

In the following section, the notion of winners and losers is discussed in
terms of climatic conditions. These conditions include today's global climate
regime, an altered climate regime, and varying rates of change.

Winners and Losers With Today's Global Climate Regime

It seems obvious that, say fifty years hence, there will be some societies
that benefit from whatever climate exists at that time. After all, with today's
climate, we can identify climate-related winners and losers. The following map
(Figure 1) shows drought-prone regions in sub-Saharan Africa, some of whic 'h could
be considered climate-related losers. Such maps, depicting drought-prone (and
flood-prone) areas, exist for other regions around the globe.

One could argue, however, that there has been little sustained (or
effective) effort to date by climate-related winners to assist those who might
be considered climate-related losers. Such a statement, of course, calls into
question how foreign aid from the international donor community has been
distributed. We have seen, for example, that in the past several decades foreign
assistance has been frequently tied to political considerations (e.g., aid to
Cambodia and South Vietnam in the 1960s and 1970s, or to Ethiopia in the 1980s).
Exampl es that justi fy such 1 ow expectati ons about adequate, apol i ti cal assi stance
from the industrialized countries are not difficult to find. In the early 1970s
when there were widespread droughts throughout the world (except in the United
States), then-Secretary of Agriculture Earl Butz spoke about how food exports
from the United States would be a new tool in the nation's foreign policy
negotiating kit. Despite statements to the contrary, few leaders in countries
chronically affected by the adverse impacts of today's climate believe that they
can rely on assistance from those favored by today's global climate.

128

Glantz

WAS MOST WCALLY AFFECTED BY THE DROUG11T

As of June 1985

TUNI IA

WESTERN
SAHARA

ALGERIA
LIBYA EGYPT

VA100 I ANIA

MA[ I
N1(A k

t,l Wd) II)AN DJIBOUTI
GUINEA
Hy t3t:NiN
NIGERIA F I 1,110PIA
Ab I
RAIL
C.E'F'T"
FRICAN R&.'@
... ....... CAMEROON
................. .
*:;Xi i@:
SIERRA
LEONE
L E TOGO UGANDA
GUINEA-BISSA EQUATORIA GAS N
RWANDA
GUINEA
hAMBIA
BURUNDI
ZAIRE

IMBASWE
NAMIBIA
NX

SWAZILAND :X
LESOTHOO
Critically affected
-:x. Most critically
affected

Localized drought is
prevalent in several
other countries.

Source: United Nations

New York Time, 8/20/85

Figure 1. Areas most critically affected by the drought.
TERN TUNI @IA
@SHARA
ALGE
@RIA
LIBY@A
II IN A

The Colorado River Compact of 1922 provides an example of a recent "climate
change" in which winners and losers have been identified. The Colorado River
Basin was divided into two parts, the Upper and Lower Basins. The flow in the
system was estimated at about 15 million acre-feet (maf) based on the record for
the previous 20-year period. The representatives of the various states in the

129

Problem Identification

basin agreed to divide in absolute terms 15 maf average annual flow equally
between the two basins: 7.5 maf for each basin (75 maf over a 10-year period).
However, because the Upper Basin states thought that there was, in fact, more
water in the system than 15 maf, they agreed to provide the lower basin states
with 7.5 maf, thinking that they would benefit from any surplus that might exist
(for further details, see Brown, 1988).

Shortly after the agreement was signed, however, the Colorado River entered
a period of low streamflow, setting record lows in the 1930s (the Dust Bowl
decade). (Today, the average annual streamflow is estimated at about 13.5 maf.)
The loss of streamflow has to be absorbed by the Upper Basin. Thus, in this
situation, one can identify winners and losers as a result from what might be
considered a climate change that has, to date, lasted about six decades.

Carrying this analysis further, one might ask what those who benefited from
the Compact have done to compensate those who have not? What lessons for climate
change responses by society might be drawn from this situation? Should future
water compacts be based on proportional divisions of a variable resource instead
of absolute amounts? What does this case study suggest about when to reach
agreement on a variable resource -- before winners and losers are identified or
after?

Finally, an important related question that merits attention, but has yet
to be addressed among discussions about possible strategic responses to global
warming, is the following: Who loses and who wins if no action is taken and the
climate remains as it is today? If it could be ascertained that no global
warming were to occur, what actions would today's climate-related winners take
to alleviate the climate-related problems of today's climate-related losers?

Winners and Losers With an Altered Global Climate Regime

While we do not even know the global let alone regional specifics of the
havoc (or windfall) that a climate change will bring, we can assume that there
will be winners and losers (however defined) with a global climate warming.

Some researchers and policymakers who are primarily concerned about the
regional impacts believe that, compared to the present climate of their region,
it is possible that their climate could improve rather than 'worsen with a global
warming. Saudi Arabia is one such example; Ethiopia may be another. Given their
current climate, they might consider the risk of change worthwhile.
Bandyopadhyaya (1983), an Indian social scientist, as well as Budyko (1988) of
the U.S.S.R., have made this argument at length in favor of a climate warming.

Often, when people talk about the possibility of increased.rainfall in a
given region, a counterargument is raised that ambient temperatures (and,
therefore, evaporation rates) will also increase. This would negate any benefits
that might come from additional rainfall. Yet, history shows that societies have
devised ways to capture rainfall and reduce evaporation, thereby improving the
percentage of rainfall that they can effectively use.

130

Glantz

Can we find examples of environmental conditions that different societies
might have to cope with in the advent of a global warming? Are there existing
climate change analogues for most places in the world? In the United States, it
has been suggested that Iowa will become hotter and drier. Might Nebraska or
Kansas provide a glimpse at Iowa's possible future environmental setting and,
therefore, a glimpse of Iowa's future? Attempts to identify climate analogues
are not new. The following maps of the U.S.S.R. (CIA, 1974) (Figure 2) and China
(Nuttonson, 1947) (Figure 3) depict agro-climate analogues from North America.
Similar analogue maps could be created that pertain to climate warming once we
have an improved regional picture of the impacts of a global warming.

Winners and Losers and Rates of Change

As we have seen with other environmental changes, it is often not the change
itself but the rapid rates of change that are so disruptive of human activities
(including the ability to adjust). If changes are slow enough (whatever that
means), their impacts may be less disruptive in the short and medium terms than
if the rates of change are much faster.

Yukovi vrrtlory

Albota
X ILI
1%0 Aw in
m" @1,I @ @ 6,11r "@ ,,

Figure 2. North American climatic analogues for U.S.S.R. crop regions.

131

Problem Identification

Gliriatic Analogues
Wyo ming Minnesota

Nebraska
@@ 47 North Dakoi
_,,W@"
Nevada la
4 4*, Kansas
Montana
04wo
7@
Kentucky
C
C
olorado

J
Oklahoma
Idaho
-@Vr- ,
41V East

e
Te nes

Oklahoma&
The North Ame6can locations Indicated have 0
temperatures and rainfall somewhat similar to
areas @n China, Comparisons such as these OW - SN.
can an*ly be Suggestm

Puerto
Rico j

Figure 3. Climatic analogues: comparing China to North America.

One of society's problems in confronting the climate change issue is the
absence of a realistic disaster scenario or "dread factor." While attempts have
been made in the recent past to identify such scenarios, they have been generally
dismissed under closer scrutiny. For example, the possibility of the
disintegration of the West Antarctic ice sheet (which would cause sea levels to
rise 8 meters) was raised at the end of the 1970s. Upon closer scrutiny of the
geophysical mechanisms involved, the probabilities associated with this happening
in the next century were sharply reduced. The use of the notion of a doubling
of CO, from pre-industrial levels was another such attempt. But, as some
observers have noted, there was nothing cataclysmic about a doubling itself.

132

G7antz

Major environmental and societal impacts could occur before as likely as after
the doubling. Interestingly, the time associated with the doubling has been
moved closer to the present by different researchers; beginning at first with
2050-2075, to 2020, and even to 2010.

Yet another attempt to identify a dread factor was the article and news
release about how the global climate regime might shift abruptly in a steplike
manner as opposed to gradually (Broecker, 1988). Steplike changes in global
climate would give societies little time to cope with and adjust to the
relatively abrupt environmental change that might ensue.

The most recent dread factor appeared in the testimony to Congress of
scientist James Hansen during the summer of 1988, in which he stated that the
four hottest years on record in North America occurred in the 1980s (U.S.
Congress, 1988). He contended that this was proof that the greenhouse effect was
in progress and that the especially severe drought of the summer of 1988 was
2
linked to the global warming. Other scientists (e.g., Trenberth et al., 1988),
have since shown that the severe drought of 1988 was most likely related to other
geophysical aspects and not necessarily to the global warming phenomenon.

Search for a dread factor in order to catalyze action is, in itself, a risky
business. Each time a new dread factor has been suggested, evaluated, and
challenged, it has failed to stand up under scientific scrutiny, thereby
diminishing the reliability and credibility of the global warming proponents.
Finally, several of the disaster scenarios cited above relate to rates of climate
change. Rates of change can have very significant impacts on society (and
therefore are especially important to political decisionmakers). They must be
examined and projected with objectivity and care.

RELATED QUESTIONS

Before attempting to identify specific winners and losers that might result
from a global warming, there are several "prior" questions that must be
addressed. In this section, some of these questions are posed and only briefly
discussed to stimulate more critical examination. The following is meant to be
suggestive of the kinds of concerns that must be raised when assessing the
societal impacts of a global warming. These, among other "prior" questions, will
be discussed at an international workshop on assessing winners and losers in a
global warming context, tentatively scheduled for late spring 1990 in Malta.

2 Editor's note: On the other hand, the Science Times section of the New
York Times on January 3 reported that Hansen agreed with Tremberth's analysis and
i mpl i ed that Hansen does not bel i eve the greenhouse ef fect to be a f actor i n heat
waves and droughts. In a letter to the Times on January 11, 1989, Hansen
responded that "as I testified to the Senate during the 1988 heat wave, the
greenhouse effect cannot be blamed for a specific drought, but it alters
probabilities ... climate models indicate that the greenhouse effect is now
becoming large enough to compete with natural climate variability."

133

Prob7em Identification

What Do We Mean by a Win or a Loss?

It is not sufficient, meaningful, or realistic to equate more rainfall than
normal with a win and less rainfall than normal with a loss. In reality, the
actual annual amount of rainfall in a given location does not by itself tell much
about agricultural production. There are numerous articles about definitions of
drought (e.g., Wilhite and Glantz, 1985). Researchers have identified
differences between meteorological, agricultural, and hydrologic droughts. If
the expected annual amount falls (no meteorological drought) but is distributed
throughout the growing season at the wrong time with respect to crop growth and
development, a sharp decline in agricultural production (an agricultural drought)
could occur.

Defining a win or a loss according to changes in evaporation rates also may
not be very useful. If evaporation rates increase, and all else remains the
same, then there will be a depletion of water resources. However, as noted
earlier, people in many arid and semiarid areas have devised ways to minimize the
impacts of high evaporation rates by the way they collect, store, and use their
available, often scanty, water resources. Thus, the dependence on a single
physical parameter to identify the costs or benefits to a society of a climate
change has severe limitations.

How Does One Measure a Win or a Loss?

One might suspect that Canada will be a winner because as temperatures
increase and the growing season lengthens, agricultural . productivity will
improve. But, what will be the impacts on Canadian fisheries, the timing of
seasonal snowmelt, or the Canadian ski industry?

Another example of the difficulty associated with measuring wins and losses
is provided by historic attempts to augment precipitation in a semiarid part of
central Colorado (U.S.A). Cloud seeders were hired to suppress hail, augment
rainfall during the growing season, and reduce rainfall during harvest, in order
to improve the productivity of hops for beer production. Another group of
farmers growing other crops (e.g., lettuce) and ranchers with different moisture
requirements in the same valley opposed these cloud seeding activities. The
conflict between the two factions became violent and the operation was eventually
halted. Thus, even@within small areas there can be different responses to
'changes in rainfall, making an objective determination of a win or a loss
exceedingly difficult.

Finally, if one group loses, but loses less than others, should they be
considered as absolute loser or relative winner?

Can Wins and Losses Be Aggregated?

While wins and losses can be added together to produce a net figure, one
must question the value of that figure. The wins (or losses) are not shared
commodities. Those who lose may not benefit in any way from those who win. For
example, when the Peruvian anchoveta fishery collapsed, those fishermen who had

134

Glantz

focused their activities (fishing gear, fishmeal processing factories, etc.) on
exploiting anchoveta were not prepared to take advantage of exploiting the sharp
increase in shrimp populations that appeared along the Peruvian and Ecuadorian
coasts. A country can expect to have both winners and losers within its borders
in the event of a climate change. While the winners may be in a position to take
care of themselves, someone will have to help the losers. Wins and losses cannot
be aggregated. A win is a win and a loss is a loss.

What Is the Relationship Between Perceptions of Wins and Losses and Actual Wins
and Losses?

Given the uncertainties surrounding the regional impacts of a global
warming, actual winners and losers within and between countries cannot be
identified with any degree of confidence. Perhaps, we will learn that in reality
everyone will lose with a global warming of the atmosphere. However, as long as
some regions or countries perceive themselves to be winners, they will act
according to this perception. Thus, the issue of winners and losers must be
addressed openly, objectively, and scientifically, if we wish to minimize the
chance that actions taken in response to a global warming will be based on
misperceptions.

How Should One Deal With the Issue of Intergenerational Equity?

Identifying winners and losers spatially, as well as temporally, must become
a concern of those dealing with the global warming issue. Arguments about
intergenerational equity have been invoked to generate support for taking action
now against global warming. We are asked to take actions today to protect future
generations from the environmental insults wrought by the present generation.
But how can intergenerational equity generate widespread support for consequences
a few generations in the future when we cannot even achieve intragenerational
equity today.

It appears that we have come to believe that any change in the status quo
is, by definition, a bad change. But the real answer to this question will
depend on who is asked to respond. A Saudi Arabian might believe that any change
in the current climate regime will most likely be better for future generations
of Saudi Arabians than the existing one. The opposite belief might be held by
a farmer in the U.S. Great Plains.

CONCLUSION

Every discipline has dealt with the concept of winners and losers --
biology, political science, sociology, economics, geography, law, ecology,
conflict resolution, risk assessment, game theory, and so on. Climate-related
impact as a result of global warming is only the latest topic that requires
consideration of winners and losers.

There have been conflicting views on whether to identify specific countries
as winners or losers in the event of a global warming of the atmosphere. There

135

Problem Identification

has also been a reluctance to discuss the possibility that there may be any
winners at all. It is time to get beyond that conflict and to ask questions that
need to be addressed so that the notion of winners and losers; can be assessed on
a more objective and realistic level.

There is a calculated risk in such a discussion. Once specific winners have
been reliably identified, there may be reluctance on their part to lend support
for global action to combat a greenhouse warming. We must take this risk. Many
issues must be resolved before we will be in a position to, identify with any
degree of confidence who those specific winners will be. In the meantime, other
issues, such as equity, definition, measurement, and perception vs. reality, must
be addressed if we ever hope to identify with some degree of confidence how
specific countries, economic sectors, and regions within countries will be
affected by climate change in the 21st century.

BIBLIOGRAPHY

Bandyopadhyaya, J. 1983. Climate and World Order: An Inquiry into the Natural
Causes of Underdevelopment. New Delhi, India: South Asian.
Broecker, W.S. 1987. Unpleasant surprises in the greenhouse? Nature 328:123-6.

Brown, B.G. 1988. Climate variability and the Colorado River Compact:
Implications for responding to climate change. In: Societal Responses to
Reg i onal Cl i mate Change: Forecast i ng by Anal ogy. Gl antz, M. H. , ed. Boul der, CO:
Westview Press. p. 279-305.

Budyki, M. 1. 1988. Anthropogenic climate changes. Paper presented at the World
Congress on Climate and Development, 7-10 November 1988, Hamburg, FRG.

Callendar, G.S. 1938. The artificial production of carbon dioxide and its
influence on temperature. Quarterly Journal of the Royal Meteorlogical Society
64:223-241.

Central Intelligence Agency. 1976. USSR: The Impact of Recent Climate Change
on Grain Production. Report ER 76-10577 U. Washington, DC: Central Intelligence
Agency.

Goldsmith, E. 1977. The future of an affluent society: The case of Canada. The
Ecologist 7:160-94.

Kellogg, W.W. 1977. Effects of Human Activities on Global Climate: A Summary
with Considerations of the Implications of a Possibly Warmer Earth. WMO Tech.
Note 156 (WMO No. 486). Geneva: WMO.

Nuttonson, M.Y. 1947. Ecological crop geography of China and its agro-climatic
analogues in North America. American Institute of Crop Ecology, International
Agro-Climatological Series, Study No. 7.

Ponte, L. 1976. The Cooling. Englewood Cliffs, NJ: Prentice-Hall.

136

Glantz

Revelle, R., and H.E. Suess. 1957. Carbon dioxide exchange between atmosphere
and ocean and the question of an increase of atmospheric CO, during the past
decades. Tellus 9:18-27.

The Impact Team. 1977. The Weather Conspiracy: The Coming of the New Ice Age.
New York: Ballantine Books.

Tsongas, P.E. 1982. Foreword. In: Regional Conflict and National Policy.
Price, K.A., ed. Washington, DC: Resources for the Future. p. xi-xiv.

Trenberth, K.E., G.W. Branstator, and P.A. Arkin. 1988. Origins of the 1988
North American drought. Science 242:1640-45.

U.S. Congress. 1988. Hearings before the Committee on Energy and Natural
Resources, U.S. Senate, 100th Congress. First Session on the Greenhouse Effect
and Global Climate Change. Washington, DC: U.S. Government Printing Office. p.
89-338.

Wilhite, D.A., and M.H. Glantz. 1985. Understanding the drought phenomenon: The
role of definitions. Water International 10:111-20.

137

OPTIONS FOR ADAPTING TO
CHANGING CLIMATE

OPTIONS FOR RESPONDING TO A RISING SEA LEVEL
AND OTHER COASTAL IMPACTS OF GLOBAL WARMING

JAMES G. TITUS
Office of Policy Analysis
U.S. Environmental Protection Agency
Washington, DC 20460

This chapter focuses on strategies for responding to (1) inundation, erosion
and flooding, and (2) saltwater intrusion. As the previous chapters show, these
are not the only problems from sea level rise, but they appear to be the most
important. Moreover, strategies that successfully addressed these problems
would generally take care of the other problems as well.

INUNDATION, EROSION, AND FLOODING

The two fundamental responses to sea level rise are (1) holding back the sea
and (2) allowing the shore to retreat. Throughout history, both of these
approaches have been applied. For two thousand years the Chinese, and for five
hundred years the Dutch have protected low-lying areas with dikes. In other
areas of the world, countless coastal towns have been abandoned or moved as the
coast eroded; the town of Dunwich (UK) has been steadily moving inland since the
time of William the Conqueror, and has rebuilt its church seven times in the last
seven centuries.

Holding Back the Sea

Strategies for holding back the sea fall broadly into two categories: dikes
and other protective walls and raising the land surface.

Dikes and Other Protective Walls

The coastal engineering profession has developed a wide variety of
structures to restrain the sea. To a large degree, the appropriate structure
depends on whether inundation, erosion, or flooding is the more serious problem.
Generally, dikes are used to protect areas from permanent inundation. To prevent
leakage, dikes must be several times as wide as they are long. Thus, their costs
include valuable coastal land and perhaps structures that must be abandoned for
the dike, as well as the direct construction costs.

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In most cases, dikes have been built along (or parallel to but inland of)
the existing shoreline. However, the Dutch have often found it more economic
to build a dike across the narrow part of a bay than around the entire shoreline;
because in the former case the dike is much shorter. Doing so can impede
shipping, and it converts the upstream part of the estuary to a freshwater lake,
which may have undesirable environmental impacts; on the other hand, it can help
solve water supply problems, as we discuss below.

In addition to the wall, a means must be devised to remove water from the
protected area. For hundreds of years, the Dutch relied on wind-driven pumps;
electric and diesel pumps are more common today. For areas that are above low
tide, it is possible to rely on gravity drainage by installing tidal gates that
open during low tide to let out the water but close at other. times to prevent
water entering.

Most of the same principals apply to protecting areas threatened by flooding
but having sufficient elevation to avoid permanent inundation, but the relative
importance of particular factors varies. An important difference is that the
problems that discourage one from closing off an estuary permanently do not
necessarily make it impractical to close it off temporarily. Hence, Venice,
London, Leningrad, and several Japanese cities are or will soon be protected by
submersible tidal barriers that remain except during major storms.

Another important difference is that structures that would not prevent
inundation may be able to stop flooding. Narrow walls would eventually leak if
flooded all the time, but may be adequate for a flood that lasts a day or so.

The differences between flood- and inundation-protection strategies would
be transitory. Areas that require flood protection in the near term would
require inundation protection in the long run. Thus, the design of any flood
protection system should consider the eventual needs as sea level rises. A
concrete floodwall that is cheaper than a dike may not be a wise long-term
investment if it will eventually have to be replaced with a dike. On the other
hand, the designers of the Venice flood barrier have explicitly considered this
issue; the barriers have been designed to eventually be retrofit with navigation
locks should be necessary to keep them permanently closed.

Different structures may be necessary where waves and erosion are a problem.
Breakwaters and many types of seawalls do not prevent flooding but provide
important protection against by deflecting storm wave energy. For preventing
erosion of areas above sea level, bulkheads and revetments are common along
calm-water areas, while seawalls, breakwaters, and rubble are used on the open
coast. In all of these cases, the principle is to prevent waves from attacking
the shore by interposing an energy-absorbing structure.

One of the greatest advantages of protecting land with walls is that
existing land uses need not be threatened, except for the areas taken up by the
dikes. Because they can be erected in a couple of decades, there is not need
to erect such structures today if an area will not require protection for 50
years. This does not imply, however, that decision makers should delay

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consideration of responses to sea level rise. The cost and adverse environmental
impacts of dikes suggests that this solution will not be appropriate everywhere;
because the other options require a greater lead time, delay consideration of
sea level rise could foreclose these options and leave future generations only
with the option of building a dike.

Raising Land Surfaces

Land surfaces can be raised by (1) artificially transporting fill material
from navigation channels, offshore, or land-based sources; (2) trapping sand as
it moves along the shore; or (3) restoring or artificially enhancing natural land
building processes. The former practice is already commonplace along beach
resorts throughout the world, and fill has been used to raise the land in areas
experiencing rapid subsidence.

An even older practice is the construction of groins to trap sand moving
along the shore. An important limitation of this approach is that erosion
protection in one area is often at the expense of increased erosion elsewhere;
hence groins are most appropriate for protecting developed areas that are
adjacent to undeveloped areas where increased erosion would be acceptable.

Restoration of natural processes could be applied to barrier islands, river
deltas, and possibly, coral atolls. The natural overwash process can enable
barrier islands to keep pace with sea level by migrating landward. Although
developed barrier islands do not migrate landward, an engineered retreat in which
the bay sides are filled as the ocean side erodes would often be far less
expensive than raising an island in place (Titus 1990).

River deltas in the natural state can keep pace with sea level rise, at
least up to a point. However, dams and river dikes prevent sediment from
reaching the Mississippi, Nile, Niger, and many other deltas (LWPP 1987; El Raey
1990; The and Awosika 1990), and these deltas are currently losing land with even
a slow rate of sea level rise. As a result, officials in the United States are
developing numerous plans to restore deltaic processes by selectively dismantling
dikes that cause the problem. As sea level rises, officials in other nations
may choose to reevaluate whether the benefits of dams and dikes outweigh the cost
of losing deltaic lands, although this will be difficult. Nevertheless, the
prospect of sea level rise provides a strong impetus for Bangladesh (Commonwealth
1989) and other nations (Broadus et al. 1986) with deltas that still flood to
avoid constructing dikes along the rivers.

Many people suspect, but no one has established, that coral atolls islands
can keep pace with at least a slowly rising sea. There is little doubt that the
coral grows with the sea, but the fate of the islands is not as clear. Some
suggest that the islands are only created during periods of stable or falling
sea level; others suggest that islands are created and destroyed with a slowly
rising sea. But even if islands can not keep pace with sea level on their own,
there is little doubt that protecting the surrounding reefs is important because
they provide both protection from waves and a source of sand that could be
artificially placed on the islands.

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Raising land surfaces has many advantages over protective walls. Most
importantly, the character is the land remains largely unchanged, which can be
important environmentally and aesthetically. In addition, this approach can be
applied incrementally, as the sea rises. Moreover, this approach can be
implemented on a decentralized basis, in which property owners raise their own
properties whenever they choose. Nevertheless, some planning is necessary so
that buildings do not end up below ground level; however, in many areas flood
regulations already require buildings to be elevated 2-3 meters above the ground.
Along San Francisco Bay, local authorities require all newly reclaimed land to
be elevated an additional 30-50 centimeters to account for future sea level
rise.

Retreating from the Shore

Abandonment of coastal settlements has occurred throughout. the ages, because
people either lacked the means to hold back the sea or found -it more burdensome
than rebuilding farther inland. In the 20th century, a new rationale has
emerged: environmental protection. Particularly in Austral iia and the United
States, many local officials are promoting policies to prevent development from
blocking the landward migration of beaches and wetlands. Because buildings often
last one hundred years and infrastructure can determine development patterns for
centuries, planning a retreat requires much greater lead times than policies to
hold back the sea.

There are three ways to foster a retreat: (1) limA development in areas
likely to be flooded; (2) allow development subject to the requirement that it
will eventually be removed (oresumed mobility) and (3) do nothing about the
problem today and eventually require developed areas to be abandoned.

Limit Development

These efforts generally involve either the purchase of land or regulations
that restrict construction. Buying coastal property and creating parks can be
desireable even without sea level rise, but it would be expensive to apply it
on more than a limited scale.

Regulations that restrict construction save the public money, but in many
countries it would be unconstitutional to prohibit development in every area
likely to be flooded by sea level rise without compensation -- and even where
it would be legal it would probably not be politically feasible. Nevertheless,
it might be possible to implement this approach for areas likely to be flooded
in the next few decades. Several states in the U.S. and Australia (?VERIFY)
already require construction to be set back from the shore a distance equal to
30-60 years of annual erosion (assuming current sea level trends), and along the
Chesapeake Bay (USA), only one house per 8 hectares is permitted within 300
meters of the shore. India prohibits new construction within 500 meters of the
ocean coast. Coastal scientists in Nigeria, Argentina, and the United Kingdom
are advocating setbacks for their nations as well.

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The chief disadvantages of this approach is that it says nothing about areas
that are already developed. Moreover, it does not perform well under
uncertainty. The restrictions have to be based on a particular amount of sea
level rise, the uncertainty of which is exceeded only by the difference in
opinion regarding how far into the future we should protect our descendants and
the environment. If the sea rises less than anticipated, property is needlessly
withdrawn from development; if it rises more than expected, the policy eventually
fails. Moreover, even if there is an accurate projection, after the sea rises
to that point the policy fails. Finally, it is not always wise to prohibit
construction of a waterfront building simply because it would eventually have
to be abandoned.

Presumed Mobility

Unlike limiting development, these policies well under uncertainty and can
be applied to areas that are already developed. Although they do not alter the
ability of governments to control development in response to current concerns,
they limit it s role in sea level rise to laying out the "rules of the game,"
-- the need to eventually allow the sea to come in. Investors and real estate
markets, which are accustomed to uncertainty, decide whether development should
proceed given that constraint.

The most widely discussed approaches to presumed mobility are (1)
prohibiting private shore protection structures and (2) long-term and conditional
leases. In the United States, Maine regulations explicitly state that bulkheads
cannot be built to prevent natural systems from migrating inland; and the owners
of large buildings that would interfere with wetlands and dunes given a one-
meter rise must submit a demolition plan before starting construction. Several
U.S. and Australian states limit bulkheads to protect wetlands.

The greatest limitation with this approach is that there is a large risk of
"backsliding," that is, that officials 50-100 years from now will be unable to
resist pleas from property that it is unfair to protect the environment at the
expense of their homes.

Leases that expire at a particular date or whenever sea level rises a
particular amount may be less vulnerable to backsliding, particularly in
societies that take contractual obligations more seriously than government
regulations. Conversion of ownership to leases would often require
compensations, but with the effective date in the remote future, the present
discounted value of the loss to the property owner -- and hence the fair
compensation -- would be small.

In the United States, coastal property is under long-term leases in many
areas. Although conditional leases that expire when sea level rise a particular
amount have not yet been implemented, the National Park Service has used
conditional leases that expire under other conditions, such as the owner's death.

The major drawback of presumed mobility is that it takes more political will
to abandon an existing area than to block development of a vacant area. However,

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if people agree to an eventual abandonment many decades in advance, political
leaders can at least appeal to the need to live up to one's part of the bargain.

Do Nothing Today

In cases where people will not have the money to hold back the sea anyway,
it may be reasonable to face the problem later and do nothing today, particularly
in areas where the population pressure is so great that the area would probably
be developed even if abandonment was certain to be necessary. However, this
approach leaves open the risk that private and public organizations will make
substantial investments in areas that must eventually be lost to the sea.

This approach is particularly unsuited to nations such as Australia and the
United States, which would be likely to retreat for the sake of environmental
protection. In spite of the difficulties of planning an abandonment today,
retreating later without a plan would be much more difficult. Deferring action
simply implies that future politicians would, have to choose between more
stringent versions of options that are politically infeasible today. Land
purchases would be even more expensive than today because more areas would have
been developed. And the outcry that would result if people.were evicted from
their homes would be far worse than the reaction to prohibiting additional
development.

SALTWATER INTRUSION

As with responses to flooding and inundation, society can respond with
either structural measures to counteract salinity increases, or by accepting and
adapting to the landward penetration of saltwater. Many of the relevant measures
have already been applied in response to droughts or increased consumption.

Preventing Salinity Increases

Because salinity increases in the coastal zone result from either increases
in seawater head (pressure) or from decreases in freshwater head, they can be
counteracted by changing the head of either water body. Increasing freshwater
pressure has been applied more often. These measures affect both human and
ecological impacts from sea level rise.

Increasing Freshwater Pressure

In the United States, dams have been constructed to protect water supplies
by maintaining sufficient flows of freshwater into Delaware and San Francisco
Bays. Along the Mississippi River, structures are being built to divert
freshwater into wetlands threatened by excessive salinity (caused by past river
modifications that had blocked the flow of freshwater).

Planning for future saltwater intrusion may be warranted long before a
crisis occurs. For example, some water authorities release fresh water from
reservoirs when salinity levels increase. Sea level rise may require more

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reservoirs in the future. While there is no need to build those dams today, now
is the time to identify the locations where they would be built if needed.
Otherwise such sites may be developed for other uses precluding the options by
which future generations can address the problem.

Increased freshwater recharge has also been used to prevent salinity
increases in groundwater. For example, although the large network of freshwater
canals in southern Florida was designed to drain the land of surface water, some
canals are now used to maintain pressure along the freshwater/saltwater interface
of Biscayne aquifer. In the Netherlands, numerous man made freshwater lakes such
as the Iselmer help to maintain freshwater pressure in the shallow aquifers.
The Maldives is modifying roadways so that rainfall will seep into groundwater
aquifers rather than run off or collect in puddles and evaporate.

Decreasing Saltwater Pressure

Barriers to saltwater penetration have been used less frequently.
Nevertheless, during the drought of 1988, the U.S. Army Corps of Engineers
designed a barrier across the bottom of the Mississippi River to prevent
saltwater from penetrating upstream to New Orleans. (Because freshwater floats
on top of saltwater, the barrier prevents saltwater from encroaching without
blocking the outward flow of freshwater.) To curtail the loss of freshwater
wetlands, gates and sluices are also used in Louisiana, to permit the outward
flow of freshwater through wetlands during a falling tide, while preventing
saltwater from invading when the tide is rising. Groundwater can also be
protected through the use of physical barriers, but this has rarely (never?) been
done.

Adapting to Salinity Increases

In the absence of physical measures to prevent salinity increases, society
can move intakes inland, shift to alternate supplies, decrease consumption, or
use saltier water. On the other hand, aquatic species respond by moving upstream
although, in some cases, habitat will be reduced because the upstream segments
of the estuary are narrowed or polluted.

Move Inland

Sea level rise by itself does not decrease the amount of freshwater flowing
into rivers and groundwater, it merely moves the interface of fresh and
saltwater. Thus, relocating intakes and wells inland may be a viable response
to sea level rise, just as moving development inland is a viable response to
erosion and flooding.

Shift to Alternate Supplies

In some cases, it may be practical to develop a new source. Along the U.S.
Atlantic coastal plain, many barrier islands have shifted to deeper aquifers as
the unconfined aquifers became salty due to overpumping. Long ago, New York City
realized that the Hudson river would not supply enough water and began taking

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water from the Delaware River as well. Nevertheless, this option is becoming
less viable as coastal communities frequently find that all available aquifers
and rivers are being exploited already.

Decrease Consumption

Decreased consumption can be viewed as a response to salinity increases or
as a measure for preventing them, since less freshwater is withdrawn. The major
premise behind conservation is that by avoiding non-essential uses, freshwater
will be preserved for essential uses. Many major metropolitan areas have used
regulations to curb outdoor (evaporative) consumption; officials in some regions
are contemplating restrictions on withdrawals from groundwater for agriculture.

Pump Saltier Water

Finally, consumers may simply draw saltier water and either send it to a
desalination plant or tolerate saltier end use. While the United States, Canada,
and Northern Europe generally take for granted that public water supplies are
safe for drinking, much of the developing world and even some cities in the
developed countries use municipal supplies for cleaning but drink only bottled
water or rainwater stored in small tanks. For some industrial uses, it may be
practical to tolerate salty water.

RELATIONSHIP AMONG RESPONSES TO SALTWATER INTRUSION AND INUNDATION, EROSION AND
FLOODING

Although the freshwater supply and shoreline retreat/flooding issues are
conceptually very different, in some cases, the responses; will have to be
considered in concert, largely because of the impact of shore protection
strategies on water supplies.

Perhaps the most important interrelationship concerns the impact of levee
and pumping systems on groundwater. Freshwater floats atop. saltwater in a
typical coastal aquifer. If an island or mainland area were -to be raised by the
amount of sea level rise, the freshwater table will tend to rise as well.
However, because land masses will not rise isostatically by an amount equivalent
to global sea level rise, the area must instead be protected with levees, and
it will be necessary to pump water out. Because the land surface will be below
sea level, areas near the coast could lose the entire freshwater table. For
cities with alternate supplies, this may not be a major concern. For more
lightly developed areas, deltas, agricultural regions, and coral atolls, however,
the potential loss of the freshwater table may be a critical concern.

The management of river deltas is another case where land protection and
salinity control are interdependent, Diversion of rivers has reduced freshwater
and sediment reaching many deltas, making them doubly vulnerable to sea level
rise. Rediverting the flow of water through deltaic wetlands can help to restore
the ability of the delta to keep pace with sea level, but perhaps at the expense
of the water supply for the areas to which the water is currently diverted.

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INTERRELATIONSHIPS OF SEA LEVEL RISE WITH OTHER IMPACTS OF GLOBAL WARMING

Coastal Defense

Sea level rise is likely to be the dominant impact of global warming
requiring a coastal defense (or retreat) response. Although increased hurricane
frequency would make areas more difficult to defend, even a doubling of hurricane
frequency would have a smaller impact on beach erosion than a 30-centimeter rise
in sea level, and the impact on sheltered shorelines would be relatively small.
Changes in storm frequency could have important impacts on flooding in some
areas, but the changes would have to be great to change substantially the basic
strategy for responding to sea level rise.

Water Supplies

By contrast, changes in climate could completely dwarf the impact of sea
level rise on water supplies. Unlike sea level rise, changes in climate could
increase or decrease the amount of available freshwater (rather than merely
shifting the fresh/saline interface inland). If droughts become less severe,
the response measures discussed above for sea level rise might not be necessary.
On the other hand, if droughts became significantly more severe and precipitation
generally decreased, some of the options might be ineffective. For example,
increased reservoir capacity would accomplish little if there was not enough
rainfall to fill them; moving intake pipes upstream would not solve the problem
if the total flow of freshwater into the river is less than the requirements of
surrounding municipalities.

INTEGRATED STRATEGIES

Except for cases in which one particular response is the unequivocal choice,
an integrated strategy must contain a decisionmaking process for deciding what
options to implement when, where, and by whom, as well as an inventory of the
response measures themselves.

The goal of a response to sea level rise is to enable future generations to
avoid adverse economic and environmental costs, without undertaking expenditures
today that, in retrospect, would have accomplished more if allocated elsewhere.
Because future climate change and sea level rise -- and to a large degree, even
the impacts of various response options -- are uncertain, there is a risk that
any action employed (as well as no action) will subsequently prove to have been
ill-advised.

Although it is desirable to minimize the risk of adverse consequences, such
a goal can take many forms. For example, investors in common stocks generally
seek to maximize the expected return, while bondholders seek to minimize the
probability of a default. A public works official might be willing to take the
chance that sea level rise will require modifications of a project, because the
tradeoff is between an investment today and the possibility of a larger cost in

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the future; on the other hand, an environmental official might not be willing
to take the risk because once an ecosystem is lost it may not be possible to
bring it back.

Strategies to address sea level rise can be either comprehensive or
opportunistic. Comprehensive strategies have been rare in coastal issues,
because responsibility and authority tend to be distributed among many
governmental bodies. Moreover, comprehensive approaches require a complete
picture of all the interrelationships of an issue. The advantage of such an
approach is that it guards against inconsistent approaches being implemented by
various parties; the disadvantage is that the desire for consistency may prevent
anything from getting done until there is a consensus of the need for action.

Opportunistic strategies simply assume that if an action is urgent and
worthwhile, it should be implemented. In some cases, the benefits of
implementing a measure outweigh the costs so greatly that even a low probability
of a significant rise in sea level justifies implementation; in other cases, the
costs may be great enough to justify action only if a large sea level rise is
fairly well established.

These two approaches are not mutually exclusive. The! first step in any
comprehensive response should be to survey the possible impacts and responses
and determine which are rational given a low probability of sea level rise, and
which would require a higher probability to justify implementation. Of those
that are justified with a low probability, one can then ask whether they would
be rendered less effective if delayed. If so, they satisfy the criteria for
urgency and should be implemented as soon as possible.

To a large degree, decisions will be based on available information about
the risks. However, large nations have the ability to improve this information
by supporting efforts to more precisely forecast future trends in sea level.
Such efforts include better climate models, monitoring sea level trends, and
improved ocean and glacial process models. Any comprehensiVE! long-term strategy
should realistically consider the opportunities for improving available
information, and determine which decisions can be made with current information
and which can be safely deferred.

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COASTAL ENGINEERING OPTIONS BY WHICH A HYPOTHETICAL
COMMUNITY MIGHT ADAPT TO CHANGING CLIMATE

JOAN POPE AND THOMAS A. CHISHOLM
Coastal Engineering Research Center
U.S. Army Waterways Experiment Station
Vicksburg, Mississippi

ABSTRACT

Projected climate change scenarios suggest that both global sea level rise
and changes in storm patterns will affect coastal processes, erosion, and
flooding. The functional and structural performance of existing coastal
navigation, and of flood and erosion control projects and other coastal
facilities and infrastructure, will be modified and most likely degraded as
natural factors exceed the conditions for which the infrastructure and facilities
were designed.

Adaptive options are needed to modify or maintain existing works. In
addition, new projects should plan for a more severe and evolving environment.
Inlet relocation, changed dredging practices, incorporation of sand management
techniques, and structural modification are potential adaptive options for
coastal navigation projects. The effectiveness of existing flood control
projects -- such as sea walls, surge barrier gates, dune fields, and levees/dikes
-- and of the routing of storm surge waters will be reduced, and new food-control
projects will be required in response to sea level rise and storm-induced
flooding. There will be increased pressure for coastal armoring and dune
construction. Many "hard" (e.g., revetments, seawalls, groins, breakwaters) and
"soft" (e.g., beach fill) erosion control devices will have reduced effectiveness
and higher maintenance requirements. Increased erosion rates will promote more
public interest in beach renourishment. However, the effectiveness of
unprotected beach fills will decrease, suggesting that combinations of hard and
soft approaches may be the only cost-effective solution. An array of coastal
engineering options is reviewed as applicable in response to the various site-
specific impacts associated with global climate change.

INTRODUCTION

Global climate models imply that the greenhouse effect will cause the
world's coastal environment and communities to experience significant impacts

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over the next century. Many cultural, commercial, and recreational resources
are endangered by both sea level rise and changes in storm patterns. Although
the level of impact is difficult to quantify, it is appropriate to review the
adaptive options that are current engineering practices and explore other more
innovative concepts. In addition, long-term coastal management strategies need
to be developed, and research needs to be conducted to better define the impacts
of global climate change and to develop responses.

The projected impacts of global climate change to the coast include a
eustatic sea level rise of 0.5 to 1.5 meters by the year 2100 due to melting of
the polar ice caps (National Research Council, 1987). In addition, global
warming implies a rise in the average sea surface temperature of 2 to 4*C (World
Meteorological Association, 1986). It has been hypothesized that this warming
will lead to changes in the world's tropical storm patterns. Hurricane seasons
are likely to be longer, with an increased occurrence of higher- i ntensi ty storms
and more storms in higher latitudes. For coastal areas, this may mean more and
higher storm surges accompanied by higher waves. Current coastal land-use
practices and protective structures are at risk as coastal processes are
modified, causing accelerated shoreline erosion and more frequent and severe
coastal flooding.

IMPACTS ON COASTAL PROJECTS

Coastal wave theory demonstrates that higher sea level and higher storm
surges mean larger waves will reach coastal structures and unprotected
shorelines. Waves will exceed the design conditions of existing protective works
and infrastructure, and new projects will need to consider more severe
conditions. Erosion rates will increase and there will be more frequent and
severe flooding of coastal lands and estuaries, higher waves in "protected"
navigation channels and mooring areas, and reduced efficiencies for existing
seawalls and revetments. Beaches will narrow and dune fields will be breached.
Because estuaries will be wider, tidal prisms will increase; this process can
lead to channel scour (endangering structures), stronger currents, development
of multiple inlet systems, and faster rates of inlet migration toward land.
Therefore, impacts to coastal navigation may include changes in channel shoaling
and scour patterns, reduced durability of structures, shifts in inlet dimensions
and locations, reduced channel and harbor navigability, and -increased damages
in mooring areas.

Erosion rates will increase and many of the "hard" (e.g., revetments,
seawalls, groin fields, breakwaters) and "soft" (e.g., beach fill) erosion
control devices be less effective and will require more maintenance. Toe scour
and higher inshore waves can damage seawalls and revetments. Groin fields and
detached breakwaters may experience increased structural damagE!, and become less
effective in retaining the desired beach widths.

Other coastal facilities and infrastructure may also experience impacts.
Cross-sectional change at inlets may cause scour around the pilings of bridges
and damages where the bridges connect to land. Shoreline recession can endanger
coastal roads and facilities such as septic systems, buildings, and utilities.

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Increased rates of alongshore (sediment) transport can shoal the intakes for
power pl ants. Damages to docks and wharves will increase as higher waves
propagate farther into the harbor.

THE SCENARIO OF RISING SEA

There are many international examples of the variety of impacts we can
expect global climate change to cause on the world's coastal areas. Although
caused by other factors, the subsidence of Venice and the Louisiana coastal
plain, the dramatic erosion of the Nile delta, the land reclamation efforts in
the Netherlands and Germany, the 15-year high-water-level cycle in the Great
Lakes (1972-1986), and the recent Hurricane Hugo all contribute to our
understanding of what sea level rise and increased tropical storm activity can
mean.

Many great cities are at risk from a change in the world's climate.
However, to illustrate the quantitative level of impact that communities are
likely to experience, we use a fictional coastal area, which we call the town
of Rising Sea (Figure 1). The magnitude of impacts to this coastal community
were computed for a rise in mean sea level or storm tides or increased storm
surges of 0.3, 0.6, and 0.9 m (Table 1). The effects of sea level rise on the
Rising Sea area were calculated using the Automated Coastal Engineering System
(ACES) package of computer programs developed at the Coastal Engineering Research
Center (Leenknecht and Szuwalski, in press) and analytic methods presented in
the Shore Protection Manual (SPM, 1984).

A rubble mound breakwater protects boats moored in the harbor. The harbor
shore is a narrow beach backed by a revetment, which protects the town from
flooding. South of the revetment is the city dock and a bridge over the south
end of a tidal marsh. The bridge leads to a resort community protected by a
seawall. On the north side of the inlet is a natural beach and dune area.

The breakwater was designed to afford adequate protection for a stillwater
depth of 4.6 m at the toe of the breakwater, which is a typical multiple-layer
stone rubble mound structure. The armor stone was sized assuming that the waves
reaching it were depth-limited to 3.6 m by the 4.6-m water depth at the toe.
The calculated stable armor size is a 7.6-M stone. When hit by 3.6-m, 9-second
waves, the breakwater transmits 0.8-m waves to the harbor.

The 0.8-m waves propagate across the harbor toward the revetment, inflicting
minimal damage to the moored fleet. The 305-m-long revetment is 1.8 m from toe
to crest and has a toe buri ed 0. 6 m bel ow grade. Under present des i gn sea 1 evel ,
there is 0.6 m of water over the toe of the revetment. The 0.5-m depth-limited
breaking wave requires a computed stone size of 18 kg. However, to prevent users
of the area from possibly dislodging the stone, the revetment is made of a 45-
kg stone, although there will be no overtopping. Undoubtedly, the winds
accompanying a design storm will blow considerable spray into the town.
Fortunately, existing drainage systems can easily handle this water. The city
docks are 0.9 m above mean sea level, and waves can pass under them without
causing damage.

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13EACIHFILL
AND DUNE

USCG

REVETMENT
BREAKWATER
CITY OF
RISING SEA DIKE

CITY
DOCKS
SEAWALL
13RIDGE

DIKE

Figure 1. Fictional coastal setting and the community of Rising Sea.

A 0.3-m sea level rise will result in 4.9 m of water at the breakwater toe.
A depth-1 imi ted wave of 3.8 m wi 11 now af fect the breakwater. Stabl e armor stone
size requirements are now 9.1 M, rather than 7.6 M. The loss of rubble mound
reduces the structure's height as armor stone is displaced. If the breakwater
does not lose crest elevation, the transmitted wave will be 1.1 m, but if it
fails only 0.2 m, the transmitted wave will be 1.3 m, and will increase damage
to the moored fleet. The revetment now has 0.9 m of water on it and is subjected
to a 0.7-m breaking wave, which requires a 61-kg rock. Assuming the structure
survives with no major damage, 0.0024 cubic meters per second of water is
delivered to the town center by overtopping. For the 305-m waterfront, this is
2,700 cubic meters per hour, which may tax the existing drainage system. Wave
crests will be about even with the pier deck and will start to cause damage.

For the scenarios of 0.6- and 0.9-m sea level rise, the situation becomes
progressively worse. With a 0.9-m rise, there is 5.5 m of water on the
breakwater toe, and a proper design would require 13.2 M stone for the resulting

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Pope and Chisholm

Table 1. Effect of Sea Level Rise on City of Rising Sea

Sea Level Rise 0 +0.3 +0.6 +0.9 m

Breakwater

Depth limit wave 3.57 3.78 4.02 4.27 m
Armor stone size 7.62 9.07 10.98 13.15 M
Transmitted wave 0.85 1.10 1.34 1.71 m
Settlement 0.15 0.30 0.61 m
Transmitted wave 1.28 1.59 1.95 m
After settlement

Revetment

Depth limit wave 0.49 0.70 0.94 1.19 m
Armor stone size 18 61 145 282 kg
Overtopping (M3/S) 0 0.0024 0.035 0.14
hectare m per hr 0 0.27 3.91 15.54
per 303 m revetment

Docks

Wave crest height 0.61 1.16 1.77 2.46 m

Tidal Prism

Upriver of bridge 70,792 82,544 95,145 108,595 m 3

Seawall

Wave impact force 429 617 846 1083 N/m

4.3-m breaking wave. The 7.6 M stone used in the original construction is only
a little over half the required weight and would be easily dislodged by wave
forces. An estimated 0.6 m of crest loss or 20% damage to the breakwater may
be optimistic. Boats would no longer be safe at their moorings in the resultant
2-m seas. Since wave energy is proportional to the height squared, the 2-m wave
would have almost 5-1/2 times the energy of the 0.8-m wave. If given notice,
the fleet would head for a safer port. In these situations, people often leave
too late, resulting in loss of lives and boats. The revetment, which is
constructed of 45-kg stone, would be severely underdesigned, with the 1.2-m
breaking wave requiring a 282-kg stone. In the unlikely event the revetment did
not fail, the town would receive 155,000 cubic meters of water per hour, which
would result in extensive flooding. If the revetment did fail the flooding would
be much worse. The docks would most likely be destroyed by wave crests over
1.5 m above the pier decks and by excessive forces on the pilings. Depth-limited

155

Adaptive Options

wave forces on the seawall, as calculated by the Minikin formula, would be over
twice what they would be before the 0.9 m of sea level rise. Overtopping for
the town revetment and flooding near the seawall would be severe.

The marsh south of the bridge was 150 m by 300 m before sea level rise.
If the land adjacent to the marsh slopes upward at 1:30 on the east and west
sides and 1:100 on the south side, the water surface and thus the tidal prism
will increase as sea level rises. This could result in increased current
velocities and sediment movement. In this case, the channel under the bridge
was 4.6 m wide and 1.8 m deep before sea level rise. The rise in sea level would
increase the cross-sectional area of the channel as the tidal prism increased.
With the expected 16% increase in cross-sectional area, there would probably not
be any significant scour around the bridge pilings for this bridge located in
the back of the estuary, a small comfort compared to all the other calamities
this community would face.

ADAPTIVE OPTIONS

Coastal response options for the impacts of global climate change fall into
three main categories: retreat, soft structures, and hard structures. Retreat
is primarily a planning approach, which involves manipulating human activities
rather than the natural environment. Soft or "dynamic" structures attempt to
modify the natural processes through management of the physical system and
maintenance practices. Hard or "static" structures involve the construction of
some permanent devices. Hard structures tend to represent the more traditional
coastal engineering approach. Table 2 summarizes the range of coastal response
adaptive options, including some new and relatively untried approaches.

Retreat options summarized in Table 2 include not only abandonment but also
the concept of restricted development and government -control led land use.
Through zoning practices, local communities can gradually influence the
complexion of a coastal development. Strong zoning codes may force an area to
be abandoned gradually or to migrate inland (roll-over communities). Flood
insurance programs that allow for rebuilding of damaged properties or
unrestricted zoning may promote a laissez-faire development, prompting
significant government investment in the construction of protective works.
Retreat may be an adaptive option for currently semi-developed or planned
developments, but there are many coastal communities where the human and
financial commitment is so great that retreat is not feasible.

Soft options listed in Table 2 include sediment transport and hydraulic
flow management procedures, which rely on maintenance and operation practices
to manipulate the natural environment. The rebuilding of beaches and dunes using
sandy material from inland or offshore sources is a fairly traditional practice.
Other, more innovative sources of material to rebuild or maintain the beach and
dune system include the bypassing of sand from around inlets to maintain the
natural longshore sediment supply (Dean, 1988), the scraping of the offshore
portion of the active profile after a significant storm to enhance the natural
-beach response (e.g., South Carolina after Hurricane Hugo), and the placement

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Pope and Chisholm

Table 2. Coastal Engineering Adaptive Options

Option Approach/structure

Retreat options Abandon to nature
Limit development
Laissez faire
Roll-over communities
Evacuation routes

Soft options Beach fill
Dunes
Beach scraping
Nearshore berms
Dredging
Sand bypassing
Vegetative plantings
Channel relocation
Hydraulic modification

Hard options Flood gates
Dikes
Levees
Seawalls
Bulkheads
Revetments
Breakwaters
Jetties
Groins
Detached breakwaters
Sediment weirs
Perched beaches
Floating breakwaters

of sandy dredged material on the offshore portion of the profile in the form of
an underwater berm or bar (McLellan, in press). The use of dredged material to
maintain wetlands is also a realistic option. Vegetative plantings can be used
to help stabilize dunes, protect the shores in relatively quiet waters, and trap
sediments to enhance wetland development.

A highly promising soft approach for adapting to climate change may be to
modify the hydraulic processes of the inlet and estuary system based on an
improved understanding of the development and exchange of the tidal prism. Such
activities could include modifying the exchange cross-section and location
between the estuary and the sea via inlet opening and closing, and channel
relocation. In addition, it may be feasible to control the tidal prism volume

157

Adaptive Options

and distribution via wetland enhancement, dikes, and modification of flow
patterns. However, these approaches require a greater understanding of the
relationship between wetland flow, tidal hydraulics, inlet processes, and the
behavior of multiple inlet systems.

Hard options listed in Table 2 include structures used in navigation, flood
control, and beach erosion control projects. Seawalls, bulkheads, revetments,
levees, and dikes that attempt to "draw a line," stopping shoreline recession
and limiting flooding. The construction of a wide-toe berm can help extend the
life of these structures. However, as sea level rises and the offshore profile
steepens, these structures must be enlarged or abandoned and replaced by new more
landward structures. Navigation structures such as breakwaters and jetties can
also be modified via higher crests, larger armor stone, or additional length to
reduce damage to the structure and improve the navigability of the harbor. In
cases where channel scour has over-steepened the toe of the structure,
threatening the structure's stability, stone aprons, training dikes, or coarse-
grained material in filling have been successfully used.

Several structural options are designed to trap the littoral sediment and
enhance the inshore. These include groins, which block the longshore moving
material; perched beaches, which capture the onshore transported material; and
sediment weirs, which are used mainly at inlets as part of navigation projects.
Some breakwater-type structures attenuate the wave energy, causing an inshore
wave sheltering. Floating breakwaters have been incorporated into navigation
projects to reduce wave action within the harbor (Hales, 1981). Detached,
permeable, and headland breakwaters have been used to maintain a beach width and
profile along receding shores (Pope and Dean 1986, Pope 1989).

For most situations, a combination of hard, soft, and retreat adaptive
options will be needed. Limited development enhanced by beach scraping or the
placement of dredged material in a nearshore berm; rehabilitation of navigational
structures, accompanied by sediment bypassing; and the construction of
breakwaters to ensure longer residence for beach fill operations are proven
combination activities that could be used in response to a rise in sea level or
increased storm severity. Each situation will be different, and the appropriate
adaptive option will need to be carefully considered.

SUMMARY

Adaptive options to potential sea level rise include relocating inlets,
modifying dredging practices, incorporating sand management techniques, and
structurally modifying navigational systems. There will be increased pressure
for coastal armoring in response to coastal erosion. At existing project sites,
structural modification, supplemental works, or coastal evacuation routes may
be appropriate options. Increased erosion rates will promote more public
interest in beach renourishment. However, the effectiveness of unprotected beach
fills will decrease over time, suggesting that combinations of hard and soft
approaches may be the only cost-effective solutions.

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Pope and Chisholm

Our fictional coastal town of Rising Sea could adapt to the impacts
associated with global climate change by modifying existing works and installing
of new works. The town could use "band-aid" approaches and simply treat the local
problem as it evolves, putting in heavier armor stone and increasing structure
heights on an as-needed basis. However, the financial commitment with this
approach will escalate rapidly, and the local quality of life could deteriorate.
Or the town could evaluate and project the nature of the process and problem and
develop long-term alternative options, such as an advance measure maintenance
and operation strategy. In the end, the community might develop a multi-action
plan that incorporates the assistance of the federal and state governments and
private industry. Dredging practices could be modified to recycle material onto
the beaches and inshore, several developed zones could be converted into
undeveloped public access areas, mooring patterns could be changed and an
interior structure added for additional protection, wetland enhancement programs
could be developed, some existing structures could be modified, and the drainage
system could be upgraded. Through the development of a long-term policy and
coastal management plan that is based both on a clear understanding of the
process and impacts of sea level rise and on an evaluation of all the rational
response options, the town of Rising Sea may make it into 22nd century.

BIBLIOGRAPHY

Dean, R.G. 1988. Sediment interaction at modified coastal inlets: processes
and policies. In: Hydrodynamics and Sediment Dynamics of Tidal Inlets, D. G.
Aubrey and L. Weisher eds. New York: Springer-Verlag.

Hales, L.Z. 1981. Floating breakwaters: state-of-the-art literature review.
CERC-Technical Report 81-1. Vicksburg, MS: U.S. Army Engineers, Coastal
Engineering Research Center, Waterways Experiment Station, 279 p.

Leenknecht, D.A., and A. Szuwalski. 1990. Automated Coastal Engineering System
Technical Reference, Vicksburg, MS: U.S. Army Engineers, Coastal Engineering
Research Center, Waterways Experiment Station. In press.

McLellan, T.N. 1990. Rationale for the design of mound structures. Journal
of Coastal Research (specialty issue). In press.

National Research Council. 1987. Responding to changes in sea level,
engineering implications. iCommittee on Engineering Implications of Changes in
Relative Mean Sea Level, Marine Board. Washington, DC: National Academy Press,
148 p.

Pope, J., and J.L. Dean. 1986. Development of design criteria for segmented
breakwaters. Proceedings of the Twentieth Coastal Engineering Conference. New
York: American Society of Civil Engineers, pp. 2144-2158.

159

Adaptive Options

Pope, J. 1989. Role of breakwaters in beach erosion control . In: Beach
Preservation Technology '89; Strategies and Alternatives in Erosion Control, L.
S. Tait, ed. Tallahassee, FL: Florida Shore and Beach Preservation Association,
Inc., pp. 167-176.

SPM. 1984. Shore Protection Manual, U.S. Army Engineers, Coastal Engineering
Research Center, Waterways Experiment Station. Washington, D.C. : U.S. Government
Printing Office.

World Meteorological Association. 1986. Report of International Conference on
Assessment of the Role of Carbon Dioxide and Other Greenhouse Gasses in Climate
Variations and Associated Impacts. Reference 661. Geneva: World Meteorological
Association, pp. 1-4.

160

THE ROLE OF COASTAL ZONE MANAGEMENT IN
SEA LEVEL RISE RESPONSE

MARCELLA JANSEN
Office of Ocean and Coastal Resource Management
National Oceanic and Atmospheric Administration
U.S. Department of Commerce
Washington, DC

ABSTRACT

Successful adaptation to the effects of sea level rise will require a
comprehensive approach to the management of the affected coastal area and its
resources. A nation's response to sea level rise is likely to be a combination
of structural and nonstructural responses.

Nonstructural adaptive responses are likely to be the most economic approach
to sea level rise in most areas, particularly those with low population density
and minimal infrastructure investment. Nonstructural adaptive responses to sea
level rise can have other values, such as resource protection, which can mitigate
the uncertainty facing policy makers and planners. The success of nonstructural
adaptive responses will require the cooperation of the affected populations.
This cooperation can best be achieved through education, resulting in.increased
public awareness of the problem and the potential solutions and their
accompanying costs, and early involvement in the decision-making process.

INTRODUCTION

The potential rise in sea level resulting from global warming will present
coastal nations with a myriad of problems, and will require governments, the
private sector, and coastal residents to make some very difficult choices. In
responding to the lots of existing land and resources, policymakers will have
to balance competing demands for resources and preserve existing social and
cultural values, without overtaxing the national economy. Any significant rise
in sea level will require consideration of both the impacts of a given policy
choice on diverse resources, and the interrelationship of those resources and
those choices.

Any successful response to sea level rise will need to rely on a
comprehensive approach to the management of coastal areas: comprehensive in terms
of both viewing the coast as a whole and taking into account all of the impacts

161

Adaptive Options

of any chosen response option. (For an opposing viewpoint, see the paper in this
section by Titus.)

IMPACTS OF SEA LEVEL RISE

Rising sea level will inundate low-lying lands immediately adjacent to the
coast as well as lands along rivers flowing into the sea. Beach areas will be
eroded, and existing wetlands will be submerged. Shorelands consisting of cliffs
and bluffs are likely to experience increased erosion and undermining, resulting
in the collapse of the-bluffs. The configuration of the coastal lands may also
change (e.g., through new inlet formation) owing to changing physical forces.

Sedimentation and Increasing Salinity

Changing land forms and water volumes caused by sea level rise will alter
coastal water movements and resulting sedimentation patterns. Estuarine areas
and rivers flowing into the coast will experience increased salinity. Coastal
aquifers will experience increased saltwater intrusion from rising seas and
possible loss of freshwater recharge areas as a result of the coastal inundation.

Loss of Wetlands and Breeding Sites

The alteration of the coastal shorelands will also significantly affect
the living resources that dwell in these areas or that depend on resident
species. The potential loss of beach areas for breeding sites for turtles and
some shorebirds could be the final blow for many species already endangered or
severely stressed. The impact of the loss of wetlands, which are critical to
the life cycle of many fish species of importance to human as a food source, will
be seen in reduced fishing harvests.

Residential and Commercial Losses

Residential and commercial'development immediately along the coast may be
threatened by inundation and may be susceptible to increased damages from the
more frequent and severe coastal storms. These changes may present particular
problems for some industries. For example, coastal electricity-generating or
industrial facilities that depend on fresh riverine waters for cooling or
manufacturing processes will face abandonment of operations or 'retooling to use
now brackish waters. As mentioned before, port operations will also require
adjustment to the changing physical conditions. The limitations on fresh
groundwater caused by saltwater intrusion may serve as a limiting factor for all
forms of future land development.

Other Losses

Uses such as recreation, tourism, and fishing, which are important to the
social, cultural, and economic well-being of coastal communities, also will be
affected by the physical changes to the beaches and wetlands.

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Jansen

RESPONSES TO SEA LEVEL RISE

Three basic management approaches can be taken in response to sea level
rise: (1) do nothing and suffer the consequences; (2) resist the rising waters
through various forms of hard and soft structures; or (3) gradually retreat.
The choice of which to do in any given circumstance will depend on a number of
factors including the following:

� the magnitude and rate of sea level rise;
� the geology and elevation of coastal land;
� the value and importance of the particular resource both to its owner
and to the economic, physical, and social health of the nation;
� the likelihood that a particular response would be successful;
� the availability of viable alternatives;
� the costs -- including economic, environmental, social, cultural, and
safety -- of the chosen response.

Structural Response

While a structural response to sea level rise is almost always possible,
it may not always be reasonable, given the economic costs involved or the adverse
environmental impacts. For example, bulkheads eventually cause the loss of
natural shorelines, which can hurt recreation, tourism, and environmental quality
(see the section on Environmental Implications of Response Strategies).
Moreover, hard structures can foreclose the retreat option (such as allowing the
migration of wetlands or barrier islands) and can commit a coastal area to an
expensive course of resistance. Nevertheless, hard structures will most likely
be the chosen response for major population centers, industrial complexes, ports,
and in some nations, agricultural land as well.

Nonstructural Responses

The following is a brief discussion of some possible non-structural
responses in light of some of the more readily apparent impacts of rising sea
level.

Abandonment of High-Risk Areas and Relocation of Coastal Structures

In the face of coastal inundation and increasing erosion, existing
structures can be abandoned or moved. Erosion and inundation of coastal lands
are a constant process along the coasts of many countries. Even without the
prospect of a significant rise in sea level, coastal structures and populations
are vulnerable to natural storm and erosion processes. The impacts of these
storms and erosion are costly to the individuals involved as well as national
economies. Therefore, relocation of populations from areas susceptible to these
natural hazards can benefit a nation, even if the extent of water rise from
global warming is less than is currently projected. In addition to reducing the
vulnerability of people and property at risk, relocation of coastal structures
can have other benefits, such as the preservation of natural areas like wetlands
and their beneficial value for fisheries, water quality, and storm protection.

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Adaptive Options

Gradual Retreat

In areas with small populations and little investment, retreat in the face
of rising waters may be the most effective and economic response to sea level
rise. This is particularly true when retreat is viewed as a long term process
that can be implemented as part of a program of land use control, and with the
recognition of the other benefits associated with these land use decisions.
Among these benefits'are protection of coastal resources and the uses that are
based on them. Retreat can also be seen as a way of mitigating the extent and
cost of eventually maintaining and rebuilding hard structures.

In many areas, the value of a gradual retreat from the shoreline has been
recognized, and several mechanisms for implementing that choice are being tried.
In the United States, approximately one-third of coastal states require new
structures to be set back from the shore. The State of South Carolina, for
,example, requires houses to be inland of the primary sand dune (where the primary
sand dune would be if the coastline had not been altered), a distance equal to
40 times the long-term annual erosion rate. This determination reflects an
attempt to protect coastal construction through its projected effective life.
The Beach Management Act also places severe restrictions on armoring the
coastline.and on rebuilding structures damaged by storms or chronic erosion.

Landward Migration of Wetlands

Given a gradual rise in sea level, wetl and areas can retreat. However,
this retreat will be possible only if inland areas do not contain barriers such
as manmade structures, and if sediment flows to these areas are not interrupted.
The decisions to allow landward migration of wetland areas to protect their
ecological values will require modification of human activities to respond to
these concerns.

THE MECHANISMS OF RETREAT

In choosing retreat, one will seek to gradually relocate the existing
population at risk to other areas, and to establish programs to prevent
population increases in areas at risk. Incentives can be established to
encourage affected populations to relocate elsewhere. For example, industry can
be encouraged to locate in safe areas through the provision of special tax
incentives for relocation and subsequent preferential hiring to individuals from
the areas impacted by the sea level rise.

Another approach would be to establish as national policy. that areas likely
to be at risk in the future should be used for economic activities that do not
require major investments for infrastructure or whose loss will have minimal
social and economic impacts. For example, areas immediately adjacent to the
coast can be made primary areas for parks and other recreation that involve
little investment. Agriculture or silviculture uses could be emphasized in areas
that are still able to support these uses, but that are known to be susceptible
to inundation in the 25- to 50-year period.

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Jansen

Allocation of increasingly limited safe oceanfront areas will also need to
give priority consideration to coastal -dependent uses that cannot readily be
located elsewhere (e.g., fisheries).

Negative incentives to encourage existing populations to relocate and to
discourage new settlement in threatened areas can be based on public policies
to limit economic loss to the country as a whole by refusing to make new public
investment in infrastructure in areas at risk, and to not repair, replace, or
improve infrastructure damaged by sea level rise or by coastal storms.

IMPLEMENTATION OF THE RETREAT OPTION

Basic to the adoption of any retreat option will be an understanding of
the existing coastline, its vulnerability to sea level rise, and the existing
use of these areas. An assessment of vulnerability also needs to be placed in
a time frame to make planning realistic while not unnecessarily foreclosing
options for development.

Limitations on freshwater will be a significant determinant of the type
and extent of coastal development. A number of strategies can be implemented
to deal with the damage to coastal aquifers:

� reduction in consumption either through regulation or pricing
structures;

� construction of additional reservoirs or development of procedures for
interbasin water transfers (these two options have the disadvantage of
being costly, of having significant environmental impacts, and of
transferring a significant burden of the support of coastal development
to inland areas); and

� desalinization and innovative methods for recycling wastewaters (the
latter option could have the additional benefit of enhancing the
protection of coastal water quality).

Unlike holding back the sea, which primarily involves the decision to commit
the economic resources to undertake the activity, the implementation of a retreat
option will require broad support among the affected populations. To achieve
this support, individuals and private-sector representatives in the affected
areas should be involved early in the decisionmaking process. Part of this
involvement must be an intensive education program directed toward increasing
the general understanding of the extent and impact of sea level rise, and the
possible response options and their impacts. Another mechanism for achieving
cooperation is technical assistance in the planning for uses and structures in
the coastal area. Sea level rise should required to be considered in
infrastructure development and land use planning.

165

Adaptive Options

Once a decision is made to retreat, it will be necessary to clearly define
the role of each level of government and the private sector in the retreat plan.
While the national government most likely will be responsible for the broad
policy decisions, actual implementation or enforcement of the retreat plan may
best be done at the lowest level of government with enforcement authority. The
advantage of concentrating implementation at the local level is that this level
is closest to the problem and the population affected, and, therefore, is more
likely to be effective at persuasion as well as enforcement. Because of the
inherent problems with enforcement, there should be some governmental override
to ensure national strategy implementation.

166

A WORLDWIDE OVERVIEW OF HEAR-FUTURE DREDGING
PROJECTS PLANNED IN THE COASTAL ZONE

ROBBERT MISDORP and RIEN BOEIJE
Ministry of Transport and Public Works
Tidal Waters Division
Koningsaade 4
The Hague, The Netherlands

INTRODUCTION

One of the goals of the Coastal Zone Management Subcommittee of the IPCC
Response Strategy Working Group is "to provide information and recommendations
to national and international policy centers, enabling decision making on coastal
zone management strategies for the next 10-20 years" (IPCC-PLANNED-CZM Meeting,
Geneva, May 9, 1989). Raising the level of awareness about the possible impacts
of sea level rise and changes in storm frequencies/intensities on projects
planned in the coastal areas of the world is therefore considered to be an IPCC-
PLANNED task.

The land-use projects planned in the coastal zones include harbor
construction, land reclamation, and urbanization, with lifetimes of 50-200 years.
Such civil engineering projects generally attract other large-scale investments
and lead to further exploitation of the coastal zone (for example, an increase
in the number of fisheries and in tourism, other commercial activities, and
groundwater and oil/gas extractions). This large increase of capital investment
and gross domestic production in the coastal zones will have to be safeguarded
in the future.

Careful technical and economic studies carried out during the planning
phase of specific coastal zone projects might reveal that extra spending now,
in anticipation of climate change, will pay off in the future.

Additional funds might be expended for the following response measures:
additional coastal defense; shifting of project locations to higher ground,
farther away from the present coastline; incorporating into construction plans
the extra space needed to accommodate sea level rise (in the case of harbour
planning, providing extra space for roll -on/roll -off operations, cargo flow, and
port management activities).

167

Problem Identification

Before such response measures can be implemented, two conditions must be
met:

1. Local, national, and international policy makers and coastal management
organizations must acknowledge the importance of long-term planning; and

2. The IPCC must agree on scenarios of sea level rise and storm changes.

In general, coastal engineering development is characterized by three types
of activities, which are accomplished in the following order: 1) dredging
activities; 2) construction of harbour quays and docks, and preparation for
urbanization and land reclamation; and 3) construction of harbor installations,
cities, industrial areas and other infrastructure. Major civil engineering
projects in the coastal areas are usually accompanied by dredging activities.
The economic value of the dredging activities is, to a large extent, indicative
of the cost of the subsequent projects to be executed. To better understand the
nature and extent of the human activities anticipated in the coastal zones and
the magnitude of the associated future capital investments, a global inventory
of future dredging projects was undertaken.

METHOD OF DATA COLLECTION

To obtain data on near-future dredging projects planned in coastal areas,
the authors consulted the world's largest dredging company, which is based in
the Netherlands and has a worldwide network of agencies and long-term experience.
Only projects having work valued at $20 million or more (U.S. dollars) were
considered. These near-future dredging projects (scheduled to occur between now
and 5 years from now) were grouped into four categories:

1. coastal protection;

2. port extension/construction;

3. industrial land reclamation; and

4. urbanization.

Each dredging project was determined to be in one of four different stages:
prospective, budgeted, pending, and executed.

RESULTS OF THE NEAR-FUTURE DREDGING PROJECT INVENTORY

This inventory covers 62 near-future dredging projects located in 36 coastal
countries (Figure 1) The worldwide coverage of near-future dredging projects
is about 85%, excluding the U.S. and U.S.S.R. dredging activities. The total
value of the 62 dredging projects is about $4 billion (U.S. dollars). Dredging
projects whose budgets are smaller than $20 million constitute about another $4
billion. Those small-scale dredging projects, although large in number, involve

168

Misdorp and Boeije

Figure 1. Locations of the major near-future dredging projects.

much smaller capital investments. The preliminary results of a similar survey
covering the dredging projects executed during the last five years reveal a
total expenditure of about $3 billion.

The percentage of capital allocated to these dredging projects.can be broken
down by stage of project and by category:

Staqe M. Category M

prospective 60 coastal protection 20

budgeted 17 port extension/ 30
construction

pending 10 industrial land 40
reclamation

executed 13 urbanization 10

The dredging projects reviewed here are mainly planned in combination with
port extensions, urbanization, and land reclamation projects. Activities related
exclusively to shore protection cover only 20% of the dredging projects
considered in this inventory.

169

Problem Identification

Figure 2 shows the regional distribution of the major dredging projects by
project stage and by category of dredging activity.

Figure 3 shows the regional distribution of the total cost for these
dredging projects; 70% of the total will be spent in Asia and in the Arabian
Gulf States. The land-use projects (e.g., land reclamation and port extension)
are predominant in Asia. In the Arabian Gulf States, the amount of capital
allocated or spent on port extension/construction, land reclamation, and
urbanization is more or less equal.

As previously stated, dredging activities provide an indication of the
future level of capital investments in the coastal zone. Experience shows that
the capital investments in coastal areas are about 5 to 15 times the dredging
costs. This means that a rough estimate of the near-future capital investments
in the coastal zones of the world might range between $20 and $60 billion. Other
types of large-scale projects, such as capital-intensive, near-future
agricultural projects, are not included here.

NEAR FUTURE MAJOR DREDGING PROJECTS WORLD WIDE
regions COASTAL PROTECTION regions : LAND RECLAMATION
europe eumw
n.affwlca excl.USA n.amerlca exd.USA
south arnerica south arnedca
medbr- (N) maditarranean (N)
niediternaanew is maditerranean (S)
West africa El west afrlca
east africa east africa
australia australla
south asla -7777777= south sale
soulh east asla south east sale
gulf states gulf states
0 100 200 300 400 SIX) 600 700 am 0 100 2DO 300 400 Soo 600 700 am
min $$ min $$
URBANISATION PORT EXTENSION

europe europe
n-amerka excl.USA I n.america excl.USA
south arnerlm south arnedca
Mediterranean (hQ "Wlte@n (N
rnsditerransan (S) moditerranean (S)
west afflca 2 west africa
east africa east africa
australla australla
south sale I south asla
south east sale south east sale
gulf aisles gulf states
0 100 200 300 400 Soo Soo 700 Soo 0 100 200 300 Soo 600 700 Soo
min $$ min $$
some remarks: El prospect E3 pending M budget N under execution
�near future projects between 1 and 5 years * total number of projects: 62
� projects > 20 min ss * data collected with a world wide coverage of 85%
Figure 2. Regional distribution of major near-future dredging projects by stage
and category of activity.

170

Misdorp and Boeije

NEAR FUTURE DREDGING PROJECTS WORLD WIDE

Regions :
Europe
N.America (excl.USA)
South America
Mediterranean (N)
Mediterranean (S)
West Africa
East Africa
Australia
South Asia
South East Asia
Gulf States

0 500 1.000
million US Dollars

N coastal protection ED urbanisation

E land reclamation El port extension

Figure 3. Regional distribution of total cost of near-future dredging projects.
considering the possible impact of sea level rise (and climate change)
during the planning phase of coastal projects.

CONCLUSIONS AND RECOMMENDATIONS

The following conclusions can be drawn, based on the global inventory
presented above:

1. Future capital investments in the coastal zones could range between $20
and $60 billion (U.S. dollars). This sum emphasizes the importance of

2. South Asia, Southeast Asia, the Arabian Gulf States, and to a smaller
degree, South America will be heavily investing in future land use

171

Problem Identification

projects, such as port extensions, (industrial) land reclamation, and
urbanization projects.

3. It appears that relatively large investments are planned for land-use
projects and that there will be relatively small investments in shore-
protection measures on vulnerable coasts. To find out whether this is
indeed the case, a global inventory of planned shore-protection
construction should be conducted.

4. To obtain more complete information on the investments in the coastal
zones, additional inventories should be taken of plans for capital-
intensive- agricultural activities (enpolderment of lagoons,
irrigation/drainage projects), freshwater management projects, and
construction of infrastructure (bridges, sluices, airports). Such
research should be conducted within the framework of IPCC working
groups.

172

ECONOMIC, ENVIRONMENTAL, LEGAL,
AND INSTITUTIONAL
IMPLICATIONS OF RESPONSE STRATEGIES

Editor's Note:

The organizers of the Miami Conference intended to have a session on the
social and cultural implications of response options, but no such papers
were received. The conference preserved the time slot by accepting papers
addressing the social implications of climate change. In this report,
those papers have been placed in the other sections.

SOCIOECONOMIC, LEGAL, INSTITUTIONAL, CULTURAL, AND
ENVIRONMENTAL ASPECTS OF MEASURES FOR THE ADAPTATION
OF COASTAL ZONES AT RISK TO SEA LEVEL RISE

JOB DROVERS, REIN BOEIJE, ROBBERT MISDORP1
Transport and Public Works
Tidal Waters Division
Koningsaade 4
The Hague, The Netherlands

ABSTRACT

In response to the consequences of climate change, in particular sea level
rise, the Coastal Zone Management report addresses adaptive policy strategies
for the coastal zones at risk. This paper investigates the effectiveness and
implementability of response strategies and formulates recommendations for
adapting to sea level rise. It presents a worldwide overview of the-major
problems raised by adaptation to sea level rise.

A second purpose of this paper is to present a methodological framework
for the elaboration of response strategies. This framework may serve as a
reference for the preparation of more detailed response plans on a national
level.

Criteria for comparing response strategies are defined and evaluated for
the world's largest coastal zones at risk. The comparison of strategies is
based, as much as possible, on the quantitative information analyzed in this
paper. The present situation is used as a reference for all considerations in
this study.

INTRODUCTION

As indicated by the Science Working Group, there is great uncertainty
concerning the degree to which sea level is expected to rise in the next century.
As a working hypothesis, a rise of I m will be considered. Information on other

'This was prepared by the Netherlands' Delegation as information for the
Coastal Zone Management report of RSWG of the IPCC. This paper was written to
stimulate discussions of the CZM subgroup at the Miami workshop held in November
1989. As such, it presents preliminary views only. It does not constitute the
policy of the Dutch government.

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Implications of Response Strategies

climate change effects, such as alteration in the frequency and intensity of
storms, is insufficient to be dealt with in this study.

The impacts of different sea level rise scenarios on coastal zones at risk
if no adaptive measures are taken have been investigated by the Impact Working
Group. These impact predictions form the basis for the response strategies
considered in this paper.

Basically, two policy response options can be distinguished: limitation
and adaptation. This study deals only with adaptation, for which two strategies
can be followed: land-use adaptation and coastal protection. Which one will
be best depends on criteria referring to the effectiveness and the
implementability of these strategies.

Carrying out the policy options requires "technical" measures (for example,
the execution of shore protection works, the institution of a coastal survey
system) and the creation of appropriate conditions for implementation by legal,
social, economic, financial, and institutional measures. These "implementation"
measures are necessary to overcome barriers that prevent technical measures from
being taken or from being effective, such as insufficient financing, lack of
technical and management know-how, legal opposition, inefficient administration,
social rejection, cultural traditions, and adverse concessions.

Elaboration of the optimal policy choice for all coastal regions at risk
in the world, including the most appropriate technical and implementation
measures, is an enormous task. It requires detailed investigations that cannot
be accomplished within the limited time available. Furthermore, the choice of
a response strategy involves the sovereignty of each concerned country, and
detailed plans are, therefore, the responsibility of local authorities.

For these reasons, the approach chosen here avoids a detailed elaboration
of strategies for each country. A set of parameters is defined and then related
to the economic, social, institutional, cultural, and environmental aspects of
various measures. They are chosen in such a manner that simply evaluating just
the order of magnitude yields an impression of the effectiveness and the
implementability of different types of measures. Thus, these parameters act as
"indicative" cri,teria. They do not serve to optimize a response strategy, but
rather to indicate the problems that are raised by that response strategy.

Finally, it should be noted that policies to protect the coastal zone
against storm events may be linked to policies regarding other (natural)
disasters: hurricanes, earthquakes, avalanches, fires, and droughts.

MEASURES

Limitation and adaptation are the main policies in combating sea level rise
in coastal zones. There is also the possibility of doing nothing. One then has
to face the consequences, which are described in Chapter 2 of the Coastal Zone
Management report: "Impacts." A brief outl.ine of different policies follows.

176

Dronkers, et al.

This paper emphasizes adaptation. It considers two different adaptive
strategies: land-use adaptation and coastal protection. In practice, not just
one type of policy will be followed. It would be most efficient to follow some
policies simultaneously, with regional differentiations.

Limitation

If the accumulation of greenhouse gases in the atmosphere continues at the
present rate, the heat budget of our planet will be strongly disturbed. The
consequences are hard to predict, but a sea level rise on the order of 6 m in
the long run cannot be ruled out. Adaptation to such a sea level rise implies
enormous loss of land and economic and cultural values. Limitation measures,
therefore, need to be considered. The impacts of prevention strategies are
investigated in other subgroups of the RSWG and will not be considered here.

Limitation aims at limiting the concentrations of greenhouse gas es in the
atmosphere in order to fight the causes of climate change and sea level rise.
Even if limitation measures are taken, the concentration of greenhouse gases in
the atmosphere will most likely increase during the next century. This brings
about the risk of an additional rise in sea level, which may amount to 1 m or
even more. Therefore, it will also be necessary to consider adaptive measures
in low-lying coastal areas.

Land-Use Adaptation

If the coastal zone at risk is used freely for living and working, the
safety of people could be permanently in danger, and valuable infrastructure
could be lost. The risks can be limited, however, by regulating the activities
in the coastal zone. Incidental flooding could be accepted, for example, if it
were sufficiently controlled so that the zone's people and most valuable
investments would remain safe.

Land-use planning in general is a powerful instrument for adaptation to
the risk of disastrous events, especially if these events are frequent and
protection is difficult. In many countries, land use is already subject to
regulation. This planning is often based on socioeconomic arguments, with risk
limitation playing a minor role. Examples of risk-limiting land-use planning
are:

� no activities that may cause subsidence (extraction of gas, oil, water;
lowering of the soil water level, etc.);
� restriction of urban development;
� no vulnerable industries with pollution risks;
� no vulnerable investments close to the seashore.

The adapted land-use strategy requires a large number of adaptive measures:

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Implications of Response Strategies

Technical Measures

Construction works should be considered to create locations (mounds) where
the population can flee the water in case of inundation. Drainage systems are
necessary for the discharge of water when. the sea level decreases after
inundation. In addition, an early warning system will be necessary to limit the
loss of lives by timely evacuation of the population to 'safe locations. A
service with appropriate skills and equipment should be created to assist damaged
regions.

Imglementation Measures

Legal adaptation will be necessary to support changes in coastal marine
boundaries and land-use planning. In high-risk areas (for example, earthquake
areas) regulations often exist, mainly referring to construction rules for
buildings. One might also consider the establishment of legal requirements for
the construction of houses in regions with risk of inundation. In many coastal
zones at risk, houses are already built on poles, but legislation exists in only
a few countries. Legal adaptation requires the creation of new institutions.

Legal requirements should also exist to clarify who 'Will carry the costs
of land-use adaptation. Such costs include the following:

� relocation of property,

� creation of employment in other parts of the country,

� loss of property and income due to inundation, and

� adaptation of infrastructure.

Regions at risk need a high degree of organization to respond to natural
disasters with a minimum of damage and loss of lives. A coastal zone
administration should be charged with planning and putting into effect adapted
land use, control, coastal survey, early warning, and rapid intervention.
Educating the population in the coastal zone is also an important concern.

Coastal Protection

Technical Measures

Protection against natural disasters can, in principle, be offered by civil
engineering works (see Chapter 4 of the CZM report). Limitation of natural
hazards by such construction works is essentially a matter of striking a long-
term economic balance between costs and benefits.

The starting point for the protective measures considered here is
maintaining the present protection level of human beings and infrastructure in
the coastal zone at risk. (As an example, the above-formulated starting point
implies that in a region protected by dikes -- assuming that other conditions

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Dronkers, et al.

remain the same -- the dikes should be raised to a level that is approximately
equal to the height of the rise in sea level). This starting point often does
not coincide with optimal coastal protection, and may even leave some coastal
regions with too low a level of protection. This is the case, in particular,
for coastal zones which at present are insufficiently protected owing, for
example, to recent land occupation or subsidence. These situations require a
solution, but in principle this is independent of sea level rise.

Protective measures can be divided into "hard" and "soft" measures. Hard
measures include raising dikes (protecting lowlands), constructing storm surge
barriers (protecting cities) or closure dams (shortening coastline), and polder

building (land reclamation). Examples of soft measures are shore face and beach
nourishment, landfill, and environmental restoration.

In many cases, the original shape and floral cover of regions at risk offer
an inexpensive and efficient means to diminish the risk and the extent of storm
surge disasters. The original environment, however, has in some cases been
strongly altered to enhance the exploitation of resources in regions at-risk.
In those cases, restoration of the natural environment should be considered.

Sea level rise will cause an increase of seepage. Infrastructural works
for water drainage are, therefore, necessary, and operational costs (pumping,
etc.) have to be considered. An overview of available techniques is given by
the U.S. delegation of the Climate Zone Management subgroup.

Implementation Measures

� An adaptive response strategy based on shore protection works is
effective only if additional implementation measures are taken.

� An economically and socially acceptable funding mechanism for protective
works has to be elaborated. Legislation has to be reviewed and
eventually revised to ensure that it is clear who owns the rights to
coastal property and who has the responsibility to protect it.

� For the construction, planning, operation, and maintenance of shore
protection works and for water management, an appropriate organization
("Coastal Works Administration") is necessary. Such an organization
should consist of an intensive and sufficiently trained staff. The
creation of training programs and the attraction of technical know-how
are, therefore, important prerequisites for the success of a protection
strategy.

IDENTIFICATION OF CRITERIA

Each of the two adaptive strategies consists of a set of technical and
implementation measures. As mentioned in the introduction, the regional
optimalization of response strategies requires a detailed quantitative impact

179

Implications of Response Strategies
evaluation, which is beyond the scope of this study. Instead, specific criteria
will be identified for use in evaluating the effectiveness and the
implementability of the adaptive strategies.

Effectiveness

Effectiveness refers to the capability of strategies to save lives and to
save economic and environmental values, taking into account the expenses of all
measures involved. As mentioned in the previous section, this study addresses
only the problem of sea level rise. Presently existing problems of insufficient
coastal protection are, in principle, left out of consideration. Consequently,
the coastal protection strategy does not go farther than maintaining the present
level of protection against inundation. Such a strategy, thus, is not very
effective in saving lives and economic values in coastal zones that at present
suffer from frequent disastrous inundations.

If in those coastal zones the choice is made for a coastal protection
strategy to respond to sea level rise, then an additional effort is required to
improve the present situation. The existence of a low coastal protection level
influences the choice of a coastal protection strategy in a negative way, as it
brings about an increase of costs.

Capability of Maintaining Safety

Coastal protection works, provided they are properly constructed and
maintained, may guarantee the safety of lives at the present level.
Land-use adaptation can, in principle, offer the same safety only if a
substantial part of the population is displaced. Massive displacements
are, however, difficult to deal with. Therefore, in countries where the
coastal zone population constitutes a significant part of the total
population, a coastal protection strategy is likely to be more effective
in protecting lives than a land-use adaptation strategy. The fraction
of the population living in the coastal zone at risk is a relevant
parameter for assessing the effectiveness of land-use adaptation in
maintaining safety.

Capability of Protecting Economic Values

Sea level rise increases the risk of loss of economic values (capital
investments, production capacity) by inundation. This risk of loss can
be diminished by land-use adaptation measures. However, certain loss of
capital investments and potential production capacity will always exist.

Coastal protection measures can prevent the risk of an increase in
economic losses, but may bring about costs that exceed the benefits.
The cost-benefit ratio is a relevant parameter for assessing the economic
effectiveness of a shore protection strategy. Without detailed studies,
only a very rough estimate can be given of this parameter. A firm
conclusion can be drawn only if the ratio is either a multiple or a small
fraction of one. In the first case, the economic values in the coastal

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Dronkers, et al.

zone at risk must be small, making land-use adaptation the most
appropriate option. In the second case, coastal protection probably is
the most effective strategy.

Capability of Protecting Environmental Values

Sea level rise inevitably affects the coastal environment, as will any
adaptive measures. The impact on the environment depends on the type of
measures considered. For example, the impact of closure dams will, in
general, be greater than the impact of raising dikes.

A great environmental impact, however, does not necessarily imply a net
loss of environmental values. Environmentally valuable new conditions
may be created. Adaptive response strategies should aim as much as
possible at creating conditions for the maintenance or development of
sustainable ecosystems with a high biological diversity.

Which strategy is most effective -- coastal protection or land-use
adaptation -- cannot be decided without detailed studies and requires
optimizing of the technical measures. Therefore, within the limited
scope of this study, no indication can be given with respect to the
environmental effectiveness of adaptive strategies.

Capability of Protecting Cultural Values

In general, a coastal protection strategy offers more possibilities to
protect cultural values in the coastal zone at risk than a land-use
adaptation strategy. The effectiveness of protection can be assessed
only on the basis of elaborate studies and plans. This criterion,
therefore, will not be considered in the further quantitative
elaboration.

Implementability

Implementability refers to the capability of countries to carry out the
adaptive strategies. This capability depends on economic, technical, cultural,
social, legal, and institutional conditions.

Economic Implementability

Implementation of a coastal protection strategy requires the availability
of sufficient financial means to afford the realization, maintenance, and
operation of coastal protection works. If a high percentage of gross
national product (GNP) is necessary for coastal protection, then
implementation of this strategy poses problems.

These problems may be partly solved by international funding. In the
long run, however, national economics should be able to afford the
maintenance and further reinforcement of coastal works. In that respect,
the ratio of costs of protection works (including maintenance and

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Implications of Response Strategies

operation) to the GNP is a relevant parameter for assessing
implementability.

Land-use adaptation places restrictions on the economic exploitation of
the coastal zone at risk. If the major contribution to the GNP
originates from the coastal zone at risk, then such restrictions may be
economically unacceptable. The fraction of the GNP contributed by the
coastal zone at risk, therefore, is a relevant parameter for assessing
the economic implementability of a land-use adaptation strategy.

Technical Implementability

Coastal protection and land-use adaptation strategies both require the
execution of technical measures. Coastal protection, however, asks for
works of a larger scale and with a higher degree of complexity than land-
use adaptation. Both strategies require technical know-how, especially
the coastal protection strategy. The availability of sufficient
technical know-how is hard to assess. The presence of hydraulic research
institutes and the number of university graduates in the country can be
considered as indicators.

Social Implementability

� Social acceptance and cooperation are important conditions for
implementing adaptive strategies. The coastal zone population is more
strongly affected by land-use adaptation than by coastal protection.
Coastal protection, however, requires economic sacrifices of the entire
population on behalf of protecting the population in the coastal zone.
Participation of the most concerned population groups in the decisions
concerning the strategy to be followed favors social acceptance and
cooperation. This is possible only if the population is well informed
and well organized socially.

If the coastal zone population constitutes a large part of the total
population, coastal protection measures will be supported in large part
by those who are directly concerned. This also favors social acceptance.
A land-use adaptation strategy that involves the migration of the most
threatened groups poses social integration problems if the displaced
groups are large in comparison to the host population. Thus, the
fraction of the population living in the coastal zone at risk is an
important assessment parameter: if this fraction is high, social
implementability of a shore protection strategy is easier than that for
a land-use adaptation strategy.

Legal Implementability

� Adaptive response strategies to sea level rise raise a considerable
number of legal questions, some of which have been raised in the previous
section. For the successful implementation of adaptive strategies, the

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Dronkers, et al.

relevant legal questions have to be settled in advance. Countries where
some form of land-use planning is already practiced may more easily
implement a land-use adaptation strategy than countries lacking this
experience. Transfer of experience to those countries will be most
useful.

Cultural Implementability

Adaptive response strategies to sea level rise should, as much as
possible, prevent the loss of cultural values in the coastal zone at risk
and should respect cultural traditions. Generally, cultural values will
be better protected by the possibilities inherent in a coastal protection
strategy than by those associated with land-use adaptation. The presence
of important cultural values in the coastal zone at risk is an argument
in favor of a coastal protection strategy. In contrast, coastal zones
that have recently been occupied and exploited could be redeserted, as
part of a land-use adaptation strategy, without great loss of cultural
values.

Institutional Implementability

Coastal protection requires administering coastal works with a staff of
highly trained technical personnel (see also the section "technical
implementability"). The effectiveness of such an organization can be
enhanced by encouraging the local population to participate in funding
and decision making, and by delegating tasks to local authorities. The
same holds even more true for a land-use adaptation strategy.

In this case, a high degree of organization of the entire coastal zone
at risk is necessary. Regulation has to take into account the coherence
of all social activities based in the coastal zone at risk. High
management skills are required. Moreover, the cooperation of the
population has to be ensured. Important conditions for success are a
sufficient degree of social organization (see also "social
implementability"), and a sufficient educational level of the population
in the coastal zone at risk. The degree of general education can be
considered as an assessment parameter, especially for the
implementability of a land-use adaptation strategy.

RESULTS FROM APPLYING THE CRITERIA

The criteria for choosing a policy to adapt to sea level rise and for
assigning priorities to certain types of measures are summarized in Table 1.
The information necessary to evaluate these criteria for the major coastal zones
at risk is displayed in Table 2. The necessary information includes the
following:

� National population of countries with major coastal zones at risk;
� Gross national product;

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Implications of Response Strategies

Table 1. Criteria for,Policy Selection

Required Required
for for
Strategies coastal Assessment land-use
Criterion protection Parameters adaptation

Effectiveness + Present protection 0

- Safety POP.CZ/POP.N -

- Economics + Benefit/cost

- Environment Dependent on detailed plans

Implementability

- Economic Cost/GP.N GP.CZ/GP.N -

- Technical + Experts 0

- Social POP.CZ/POP.N -

- Legal Planning exists +

- Cultural Values

- Institutional 0 Education +

CZ Coastal zone at risk.
POP. = Population.
N = National.
GP. Gross product.
Cost Cost of maintaining present level of coastal protection.
Benefit = Increase of economic risk for 1 m sea level rise.
Required: + high/much
o medium
low/few
no requirement

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Dronkers, et 0.

Table 2. Source Data for Policy Selection

Shore- Prot.
POP.N GP.N length cost POP.CZ GP.CZ Benefit
Country *108 *109 $ km *106 s *106 *109$ *109 $

Argentina 32 35 2,000 200 3.2 3.5 0.1225
Bangladesh 108 15.3 2,000 200 15.12 2.1 0.0735
Brazil 140 240 2,000 200 1.4 2.5 0.0875
China 1,000 1,500 2,000 200 10 15 0.525
Egypt 50 63 1,800 180 8 10 0.35
Gambia 0.7 0.5 400 40 0.161 0.1 0.0035
Indonesia 180 90 2,000 200 18 9 0.315
Iraq 16 40 100 10 0.96 2.4 0.084
Italy 58 670 400 40 1.74 20 0.7
Maldives 0.2 0.09 400 40 0.2 0.09 0.00315
Mozambique 15 3.9 1,000 100 1.5 0.4 0.014
Netherlands 15 203 700 90 8.1 110 3.85
Nigeria 105 100 2,000 200 10.5 10 0.35
Pakistan 106 40 1,600 160 3.18 1.2 0.042
Senegal 7 4.7 1,000 100 0.98 0.7 0.0245
Surinam 0.4 1 600 60 0.252 0.6 0.021
Thailand 56 40 400 40 7.84 5.6 0.196
U.S.A. 250 6,000 1,600 160 2.5 60 2.1
Vietnam 60 ?) 12 1,000 100 6 1.2 0.042
Total 1-,199.3 9,058.40 23,000 2,320 99.633 254.39 8.90365

GP = Gross product [$/year]
CZ = Coastal zone
POP = Population
N = National
Cost = Cost of maintaining present level of protection [$/year].
Benefit = Increase of economic risk for 1 m sea level rise [$/year].
Thumb rules:
GP.CZ/GP.N = POP.CZ/POP.N
FREQ = Increase of inundation frequency = 0.01
CAP.INV = Capital investment in CZ = 5* GP.CZ
Benefit = FREQ * (0.5 * CAP.INV + GP.CZ) - 0.035 * GP.CZ
Cost = 100,000 * shore length (km)

Sources: The Europa Yearbook 1988. World Survey, Vol. I and 2, Europa Publ . Ltd.,
1988, London; Times World Atlas; Criteria for Assessing Vulnerability to Sea Level
Rise - A Global Inventory of High Risk Areas. UNEP/Delft Hydraulics, May 1989,
Report nr. H838; Dutch Coastal Protection after 1990. Ministry of Transport and
Public Works, Rijkswaterstaat, Tidal Water Division, April 1989 (in Dutch).

185

Imp7ications of Response Strategies

Shore length (including floodplains and bays) of the coastal zone at risk;
Cost of maintaining safety at the present level;
Population of the coastal zones at risk;
Gross product of the coastal zones at risk; and
Increase of economic risk (average loss of values due to inundation) at 1
m sea level rise.

The assessment parameters corresponding to the criteria in Table 3 are
presented in a number of world maps and summarized for each country and each strategy
in Tables 4 and 5. The status of the present information is very preliminary. Some
data are obtained by applying rough approximations and only have an indicative value;
the workshops of Miami and Perth should provide more complete and reliable data.

For the assessment parameters, only three ranges of values are indicated, with
the medium range corresponding more or less to a world average. This qualitative
approach is chosen not only because of the uncertainty of the underlying data, but
also because of the objective of this study, which is limited to worldwide
indications. The assessment parameters and corresponding low, medium, and high
ranges are indicated in Table 3.

DISCUSSION

As stated in the introduction, the aim of this study is, to the extent
possible, to express policy implications of climate change and sea level rise in
measurable quantities. At the present state of this study, the quality and
completeness of the input data are insufficient to draw reliable conclusions. The
writing of this section should, therefore, be postponed.

However, to test the usefulness of the chosen approach, a preliminary version
is drafted. This section, which should be considered mainly as an exercise, will
discuss the following subjects:

� Which coastal zones at risk already have an implementable and effective
strategy for adapting to sea level rise?

� For which coastal zones at risk is the implementation of an effective
strategy a problem that cannot be solved in the short term by national
means?

� What actions at a national level can improve the implementability and the
effectiveness of adaptive strategies?

� What international actions can assist in the national implementation of
adaptive strategies?

Inspection of the set of criteria shown in Table 1 leads to the following
conclusions:

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Dronkers, et al.

Table 3. Assessment Parameters

Parameter Description Low Medium High

Present (Frequency of inundation) per < 10 10-100 > 100
protection (year)

POP.CZ/POP.N Fraction of the population living < 10% 10-50% > 50%
in the coastal zone at risk.

Benefit/cost Increase of risk of economic < 0.5 0.5-2 > 2
losses at 1 m sea level rise
vs. cost of maintaining present
level of coastal protection

Cost/GP.N Cost of maintaining present level < 0.005 0.005-0.05 > 0.05
of coastal protection vs. gross
national product

GP.CZ/GP.N Fraction of gross national product < 10% 10-50% > 50%
originating from the coastal zone
at risk

Experts Presence of a hydraulic institute No/No Yes/No Yes/Yes
and/or a relative number of No/Yes
graduates superior to the world
average

Education Educational level < 0.5 0.5-1.5 > 1.5

Planning Land-use planning exists No Yes

Values Important cultural values are No Yes
present

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Implications of Response Strategies

Table 4. Assessment Parameters for Coastal Protection Strategy

Effectiveness - Implementability

Technical: Economic: Economic: Present
Country experts benefit/cost cost/GP.N protection

Required H H L H

Argentina M M

Bangladesh L M

Brazil L L

China H L

Egypt H L

Gambia L H

Indonesia M L

Iraq H L

Italy H L

Maldives L H

Mozambique L M

Netherlands H L

Nigeria M L

Pakistan L L

Senegal L M

Surinam L H

Thailand H L

USA H L

Vietnam L M

H = High
M = Medium
L = Low
Not yet available.

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Dronkers, et al.

Table 5. Assessment Parameters for Land-Use Adaptation Strategy

Effectiveness Implementab lity
Legal Insti-
Lives Economic Economic Social planning Cultural tutional
Country POP.CZ/POP.N benefit/cost GP.CZ/GP.N POP.CZ/POP.N exists values education

Required L L L L H L H

Argentina L M L L M

Bangladesh M L M M L

Brazil L L L L M

China L H L L M

Egypt M H M M M

Gambia M L M M M

Indonesia L M L L M

Iraq L H L L M

Italy L H L L H

Maldives H L H H M

Mozambique L L L L L

Netherlands H H H H H

Nigeria L M L L M

Pakistan L L L L L

Senegal M L M M L

Surinam H L H H H

Thailand M H M M M

USA L H L L H

Vietnam L L L L M

H = High
M = Medium
L = Low
= Not yet available.

189

Implications of Response Strategies

1.) Nations with a high GNP:PROTECTION COST ratio and sufficient technical
know-how are capable of implementing a coastal protection strategy. For some
parts of the coastal zone, a land-use adaptation strategy may be chosen if this
is more effective and more easily implemented.

Most of the developed countries are in this position (see Table 4). The
implementation and effectiveness of adaptive strategies may be improved by
observing national recommendations (see below).

2.) Nations with a medium GNP:PROTECTION COST ratio will hardly be able
to afford protection of the entire coastal zone at risk, especially if the
present protection level is already (too) low. If, in addition, a high fraction
of the population is living in the coastal zone at risk, and if a high fraction
of the GNP originates from this area, then the alternative land-use adaptation
is hard to implement. Nations facing such a problem are Bangladesh and, to a
lesser degree, Senegal. In these countries, the conditions for institutional
implementation are also unfavorable because of the population's low educational
level. The latter problem may also impede the implementation of a land-use
adaptation strategy in Mozambique (see Table 5).

3.) Nations with a low GNP:PROTECTION COST ratio can hardly afford any
coastal protection. If a high fraction of the population lives in the coastal
zone at risk and provides a substantial part of the national income, then the
alternative of land-use adaptation strategy also is hardly practical. Nations
in this position are the Maldives, Surinam and, to a lesser degree, Gambia (see
Table 5). With the present national means, these nations cannot adapt to sea
level rise in an effective and implementable manner. Therefore, a considerable
fraction of the population, prosperity, and cultural values will be subject to
high risk if no international assistance is provided.

The above conclusions should lead to actions on national and international
levels.

National Actions

Recommendations for action at a national level mainly follow from the
conditions for effectiveness and implementability. Tables 4 and 5 show that a
number of these conditions are better satisfied in some countries than in others.
The list of recommendations may, however, be used 'as a checklist for actions that
should eventually be undertaken. The actions are listed in the approximate order
in which they have to be taken.

National Policy Analysis of the Sea Level Rise Issue

Such an analysis may follow the lines of this study, but should be more
detailed. It should prepare a policy decision for the optimal strategy to be
followed and it should yield insight into the actions to be undertaken. It
should be clear whether the present situation can be considered as a reference,
or whether a higher protection level is needed.

190

Dronkers, et al.

Detection of Activities or Construction Detrimental to Coastal Safety

Examples are human-induced subsidence or diversion of sediment from eroding
parts of the coast. Measures to stop these activities, adapt construction, or
diminish the negative effects should be considered. In principle, the emission
of greenhouse gases also falls into this category of actions.

Collection of Knowledge of Coastal Zone Management

Countries that are in similar situations should be encouraged to exchange
information on how to deal with coastal problems. Coastal zone management staff
members should participate in training programs.

Administration

The responsibilities of coastal defense should be clearly established,
along with the proprietorship of the shore zone and coastal protection
structures. Planning, construction, maintenance, and operation of coastal
infrastructure, regulation and control, information, early warning, intervention,
and assistance are tasks that need to be carried out. Participation of the
coastal population in decision making and funding should be considered.
Executive tasks can be delegated to local authorities.

Land-Use Planning

Any new developments in the coastal zone at risk should be examined with
respect to their sensitivity to sea level rise. Risk-limiting regulations are
necessary for the installation of new activities. Space for coastal retreat or
for protection works should be reserved. Environmental values in the coastal
zone need protection. When land-use planning is implemented, indemnity of
expropriation should be regulated.

Coastal Survey and Early Warning

Regular inspection of coastal protection structures is necessary to detect
shore retreat and a diminished capability of the protective structures to resist
storm surges. A service should be established to take charge of short-term
prediction of storm surges and early warning of potential danger.

Environmental Restoration

In many cases, the natural environment contributes to the safety of the
coastal zone against inundation. Restoration should be considered in those
regions where the coastal environment has been altered by human activities.

Education

The population of the coastal zone at risk must become aware of the
potential danger of flooding to better understand and obey risk-limiting
regulations. Information programs for the population should be organized.

191

Implications of Response Strategies

Attention should be given to the importanc.e-.of birth control in densely populated
coastal zones at risk.

Funding

In national financial planning, funds should be reserved for coastal
protection. An equitable cost sharing should be devised between the population
of the coastal zone at risk and the rest of the nation, and between different
categories of the population.

Technical Measures

Technical measures should be elaborated, estimated, and planned to prepare
for the execution of the preferred adaptive.strategy. Any existing backlog of
coastal protection has to be addressed by reinforcement of coastal protection
works, creation of high-water flightareas, etc.

International Actions

The international community can'assist coastal zones at risk to adapt to
sea level rise in essentially three areas.

Technological Assistance

The United Nations can establish a service of experts in adaptive measures,
who would be available to assist any country with a coastal zone at risk. A
paper on this subject has been prepared by the IPCC-RSWG as part of its Task B
activities.

Financial Assistance

For the nations with medium or low GNP:PROTECTION COST ratio, funding is
one of the major problems in adapting to sea level rise. Possible funding
mechanisms will be discussed in more detail in the chapter prepared by the
delegation of New Zealand.

Relocation

Some nations may encounter unsolvable problems in the implementation of
both a coastal protection strategy and a land-use adaptation strategy. This may
be the case for certain atoll islands (for example, the Maldives). With a sea
level rise of 2 m or more, these nations will disappear entirely. Appropriate
technical protection measures are hardly available. Certain islands will have
to be abandoned.

International assistance will be necessary to facilitate the integration
of these populations into other countries. The eventual disappearance of certain
nations poses problems that deserve the attention of the international community.
The United Nations should designate a special commission to prepare possible

192

Dronkers, et al.

solutions for relocation problems. Such a commission might address the problem
of "environmental refugees" due to global changes in a broader sense.

BIBLIOGRAPHY

Cendrero, A. 1989. Planning and management in the coastal zone. Ocean &
Shoreline Management 12.

Charlier, R.H. 1989. Coastal Zone: Occupance, Management & Shoreline
Management 12.

Climate Impact Assessment. 1985. SCOPE Report 27. R.W. Kates, J.H. Ausubel,
M. Berberian, eds. New York: John Wiley & Sons.

Commonwealth Secretariat, ed. Climate Change: Meeting the Challenge, 1989.
Commonwealth Group of Experts.

Responding to Changes in Sea Level, Engineering Implications. 1987. National
Committee on Engineering Implications of Changes in Relative Mean Sea Level.
New York: Academic Press.

Scientific American. 1989. Managing Planet Earth. Special issue. September.

United Nations Environment Program/Delft Hydraulics. 1989. High Risk Areas:
Criteria for Assessing Vulnerability to Sea Level Rise - A global inventory to
Report No. H838. May.

Wind, H.G., ed. 1987. Impact of Sea Level Rise on Society. Balkema.

Workshop on Sea Level Rise and Coastal Processes, Miami, 1989. A.J. Mehta, R.M.
Cushman, eds. Washington, DC: U.S. Department of Energy, DOE/NBB-0086.

Workshop on Rising Sea Level and Subsiding Coastal Areas, Bangkok, 1988. SCOPE
Report (in press).

193

ENVIRONMENTAL IMPLICATIONS

ENVIRONMENTAL IMPLICATIONS OF SHORE PROTECTION
STRATEGIES ALONG OPEN COASTS
(WITH A FOCUS ON THE UNITED STATES)

DR. STEPHEN P. LEATHERMAN, DIRECTOR
Laboratory for Coastal Research
University of Maryland
College Park, Maryland 20742

INTRODUCTION

Land loss is a major problem along the U.S. coasts (Figure 1). Erosion was
first identified along the New Jersey coast where some of the earliest beachfront
development of hotels and cottages occurred. Almost every conceivable form of
shore protection has been attempted in northern New Jersey, including
construction of seawalls, groins, and jetties as well as beach nourishment. Sea
level rise induces coastal erosion, and the accelerated rate of rise due to
global warming will only exacerbate the present problems.

SHORE STABILIZATION

Shore stabilization measures can be divided into two categories: rigid
and nonrigid (U.S. Army Corps of Engineers, 1984). The former often involves
the emplacement of seawalls, bulkheads and breakwaters (shore-parallel
structures), and jetties and groins (shore-perpendicular structures). Each of
these structures has been shown to induce adverse effects in particular settings.
For instance, the Ocean City inlet jetties have caused sand blockage along the
Maryland coast for 50 years; the result has been the downdrift erosion of
northern Assateague Island (a national seashore) at a rate of 10 meters per year.
Sea Bright, New Jersey, is protected by a massive seawall, but at the expense
of the recreational beach.

Elsewhere, groins have been shown to cause extensive damage to downdrift
beaches, the most infamous case perhaps being Westhampton Beach at Long Island,
New York.

197

Environmental Implications

"jib

Figure 1. Continuing shore erosion threatens this parking lot at Coast Guard
Beach, Cape Cod, Massachusetts. This is a national problem as best estimates
are that about 90 percent of the U.S. sandy beaches are experiencing erosion.

The nonrigid approaches of beach nourishment and dune building are generally
preferred by coastal communities because the soft interface of a sandy beach is
preserved for recreational pursuits, and yet storm protection can be gained if
adequate sand quantities are available. This approach has the least
environmental impact of any approach, but care still must be exercised. Possible
problems involve both the dredging and placement of sand. Biologically
productive sandy shores must be delineated, and they must not be disturbed.
Also, adjacent declinate ecosystems, such as coral reefs, must be carefully
guarded to protect them during dredging operations. Actual placement of the
offshore sand on the beach will obvious ly kill any of the marine organisms in
the dredged material as well as bury the beach invertebrates (e.g., ghost and
mole crabs). Studies have shown, however, that the beach ecosystem recovers in
a few years because organisms living in such a dynamic environment are adjusted
to severe perturbations from storms and can repopulate the nourished beach.

198

Leatherman

Shore-Parallel Structures

Shore-parallel rigid engineering structures can be further subdivided into
onshore (seawalls, bulkheads, and revetments) and offshore (breakwaters)
approaches. The Galveston seawall along the north Texas coast is probably the
most important such structure in the United States. On September 8, 1900,
Galveston was demolished by a major hurricane, and 6,000 people were killed.
A seawall constructed after this disaster successfully protected the residents
and buildings from direct storm assault on the city (Figure 2). The seawall was
constructed approximately 100 meters landward of the shoreline in 1904, but the
beach had completely disappeared three decades later (National Research Council,
1987). While the seawall has functioned well, the recreational beach has been
lost along this eroding shore. Additional riprap and groins have been emplaced
to protect the seawall toe and to prevent failure by undermining during a severe
storm.

Seawalls are constructed to protect the upland areas at the expense of the
beach along retreating coasts. Most likely the seawall would not have been built
if the beaches had been stable or accreting. It is easy to understand why the
beach will be pinched out of existence with the confluence of a migrating
shoreline and a static structure.

Figure 2. The Galveston seawall has been effective in protecting the city from
certain hurricane destruction but at the expense of the recreational beach.

199

Environmental Implications

There is much conjecture that seawalls actually accelerate erosion of
beaches by reflecting a portion of the incident wave energy and increasing
turbulence at least locally. While it is clear that a certain portion of the
wave energy can "rebound" off the frontal face of the seawall, it has not been
proven scientifically that seawalls actually increase beach erosion despite all
the rhetoric to the contrary by environmental zealots. This issue needs to be
thoroughly researched by laboratory studies and, especially, by quantitative
field studies.

Some coastal states have banned further seawall construction, notably North
Carolina and Maine. Their position is that the shore should be allowed to
naturally retreat and still maintain the recreational beaches. Because incessant
beach erosion will eventually result in destruction of human development without
protection, the rhetorical question here is, "Do you want bedrooms or beaches?"
No new major seawalls are presently being planned in the United States, largely
because of their huge expense and the public's preference for "soft" solutions.

It should also be kept in mind that seawalls and bulkheads do not always
work. These structures can be destroyed in a storm or simply overtopped by a
very high storm surge as happened during Hurricane Hugo along Folly Island, South
Carolina (Leatherman and Moller, 1990).

Breakwaters are emplaced offshore to break down the waves, reducing the
wave energy and longshore currents. Unfortunately, these massive structures are
often too effective in this regard, causing severe erosion of downdrift beaches
such as at Santa Monica, California. This breakwater did not work correctly
(i.e., as designed) until it was subsequently damaged in a 1950s storm to allow
some wave energy to pass through and prevent the building of a beach tombolbo
(Weigel, 1964).

The classic case of the adverse environmental impacts of breakwaters is
illustrated by the one built in Santa Barbara, California. This breakwater was
constructed during 1927-28 to provide safe anchorage for recreational boats
(Figure 3). The implications were not immediately evident even as the downdrift
beaches experienced severe erosion and storm destruction of buildings and
infrastructure. The cause and effect relationship wa 's only later realized;
attention was drawn to the adverse impacts of these coastal engineering
structures when the littoral drift system was interrupted. Breakwaters are
expensive to build and maintain, and they have found little utility along the
U.S. coasts.

Shore-Perpendicular Structures

The two common types of coastal engineering structures built perpendicular
to the shore are groins and jetties. Groins are the most widely used structures
in the coastal zone, but they are also perhaps the least understood in terms of
their engineering design. Groin design is considered both an art and a science
in terms of their length, spacing, height, and permeability.

200

Leatherman

AWL.

Figure 3. The Santa Barbara breakwater and harbor represent a classic case of
interruption of the longshore sediment transport system with updrift accumulation
of sand as a spit and severe erosion of adjacent,. downdrift beaches.

The current debate and dilemma surrounding the Westhampton Beach groin
field epitomizes the problem for downdrift property owners (Figure 4). The
affected parties are lodging a $200 million lawsuit against the county, state,
and federal governments for the loss of their beach and now their houses. It
should be noted that this groin field was not built to engineering specifications
with respect to completion of the entire field or sand emplacement requirements.
This case illustrates the "politics of shore erosion" (Tanski and Bokuniewicz,
1989).

Groins essentially "rob Peter to pay Paul" as no new sand is created, just
redistributed across the beach profile. This question of "sand rights" in the
coastal zone could be considered as akin to riparian (water) rights in the U.S.
Southwest. It should also be remembered that groins do not always work. For
example, Hurricane Hugo swept over Folly Beach and the existing groins seemed
to play little role (negative or beneficial).

201

Environmental Implications

A*-

Figure 4. The effects of groins on the shoreline at Westhampton Beach, Long
Island, New York, are obvious. While some property owners have greatly benefited
from the emplacement of these shore-perpendicular structures, the downdrift
beaches are quickly retreating and the sea is actively claiming residences.

Jetties are constructed at entrances to tidal inlets to maintain an open
channel for navigational purposes. Jetties often serve as total littoral
barriers to longshore sediment transport, and therefore these large, rigid
structures can result in extreme starvation of downdrift beaches.

Ocean City, Maryland, serves as a good case study of the impacts of jetties
on the adjacent shorelines (Figure 5). A severe hurricane in August 1933 opened
this inlet, and it was consequently stabilized by the Corps of Engineers during
1934-35. As the updrift shoreline accreted, the Ocean City fishing pier had to
be lengthened twice. The jetties filled to capacity in the 1950s, capturing all
the sand possible updrift of the jetties. Since this time, the sand has been
shunted offshore to form an immense ebb tidal shoal.

202

Leatherman

@WAW

na,
@F

Al,

Figure 6. Ccean City Xnlet divides the Maryland coast into Fenwick Island (site
of Ocean City) and Assateague Island National Seashore. Prior to inlet breaching
and subsequent inlet stabilization, this shoreline was relatively straight. The
large-sca'@e offset at the inlet and arc of erosion along northern Assateague
Hsland are visible from space.

The jetties have completely blocked the sediment moving southward along
the coast at an annual net rate of 114,000 cubic meters per year so that northern
Assateague Xsland has been sand starved, rapidly retreating landward with an
average eros*on rate of 11 meters per year (Leatherman, 1984). During the past
50 years, since inlet stabilization, the northern end of the island has already
migrated landward more than its width into the adjacent bay. It is expected that
this tflll result in the next few decades in a 3-kilometer-wide breach in the
barrier island continuity along the Maryland shore (Figure 6). Installation of
a sand bypassing system, which is critically needed, is not expected because of
the initial large expense, high operating costs, and problems elsewhere with
reliability.

203

EnvlronmenW Imp7ications

1980 SHORELINE

Snug Harbor

cean City
skwux" Bay Airport

Manfic Owen

PROJECTED YEAR 2020 SHORELINE

Snug Harbor

Ocean City
skwLWOM say Airport

Adandc Ocean

Figure 6. A large breach in northern Assateague Island is predicted based on
an extrapolation of historical shoreline changes. Ocean City citizens and
Maryland politicians do not seem alarmed about this eventuality because "ponies
don't vote."
Snug Harbor
0

e@,ancity
@OcA rport
==f=D

204

Leatherman

Some jetties have been designed on insufficient information or on erroneous
analysis of existing data. A case in point is the east pass of Coctawhatchee
Bay, where the weir section was placed on the wrong side of the channel
(Leatherman, 1989). The long-term, net direction of longshore sediment transport
had not been correctly determined, resulting in design failure of this
engineering work.

Beach Nourishment

There has been a shift from rigid or hard engineering structures to nonrigid
or soft engineering solutions in the past few decades. By placing sand from
outside the nearshore sand-sharing system, it is possible to build back the
beach and maintain this soft interface. Beach nourishment is the method of
choice for most U.S. coastal communities as a means of providing recreational
beaches and storm buffers.

Sand nourishment involves dredging material from a source area and dumping
it on the nearshore area to create or augment an existing beach. In both areas,
care must be exercised to avoid environmental problems. The source material must
be compatible with the existing beach material in terms of grain size and
chemical qualities (e.g., not polluted). In earlier times, material was dredged
from the bays and lagoons and pumped onto the adjacent beaches. While
inexpensive per volume extractedi much of the material was too fine to remain
on the open-coast beach. Perhaps more important, highly productive estuarine
sediments were disturbed, resulting in mass mortality of endemic species. This
practice has ceased along the U.S. coasts because of its environmental
implications and ineffectiveness.

Sand for beach nourishment is now largely obtained from offshore shoals
that are sufficiently far out to ensure that their removal does not accelerate
erosion (Figure 7). Environmental inventories are necessary to evaluate and
avoid highly productive offshore shellfish beds, especially clams. Also, the
dredgers should avoid excavating deep holes in the seabed that will change wave
refraction patterns, perhaps concentrating wave energy on one part of the shore.
In Florida, special care was taken because the sand was being dredged from
between coral reefs, which are susceptible to high water turbidity. While the
Miami Beach project was well planned and executed, the anchor lines on the dredge
ships were moved across the tops of the reefs by currents, scraping off the
living organisms.

Water turbidity can also be a problem with sand emplacement unless the
material is devoid of fine-grained sediments. In any case, the beach
invertebrates (e.g., ghost and mole crabs on the U.S. Atlantic coast) will be
buried and killed by sand pumping and burial. Fortunately, these populations
can recover quickly, and species numbers can be back to normal within a few years
following beach nourishment.

205

Environmental Implications

Ok@

Figure 7. Beach nourishment along the Florida Atlantic coast is the preferred
response to mitigate erosional problems and to maintain a wide recreational
beach.

SUMMARY

Beach nourishment is considered the most environmentally sensible and
compatible form of shore protection. Some people also argue that if the sand
filling is a mistake, then much less damage has been done to the coastal
environment than with emplacement of hard engineering structures. After all,
nature can take care of the problem by washing the sand away. By contrast, hard
engineering structures rarely have been removed once emplaced regardless of the
adverse consequences. The environmental implications and the long-term economic
costs have often been underestimated in the continuing process to "shore-up" the
coast.

206

Leatherman

BIBLIOGRAPHY

Leatherman, S. P. 1984. Shoreline evolution of north Assateague Island,
Maryland. Shore and Beach 52:3-10.

Leatherman, S. P. 1989. Coasts and beaches. In: Heritage of Engineering
Geology, the First Hundred Years. Geological Society of American, in press.

Leatherman, S.P., and J. Moller. 1990. Impacts of hurricane Hugo on the South
Carolina coast (in preparation).

National Research Council. 1987. Responding to Changes in Sea Level:
Engineering Implications. Washington, DC: National Academy of Sciences Press,
148 pp.

Tanski, J., and H. Bokuniewicz, eds. 1988. Westhampton Beach: Options for the
Future. Stony Brook, NY: New York Sea Grant Reprint Series, 28 pp.

U.S. Army Corps of Engineers. 1984. Shore Protection Manual. Vicksburg, MS:
Army Corps of Engineers, Wasterways Experiment Station.

Wiegel, R.L. 1964. Oceanographical Engineering. Englewood Cliffs, NJ: Prentice
Hall, 532 pp.

207

IMPLICATIONS OF RESPONSE STRATEGIES FOR WATER QUALITY

RICHARD A. PARK
Holcomb Research Institute
Butler University
Indianapolis, Indiana.46208

ABSTRACT

Human responses to projected climate changes and associated sea level rise
will affect water quality in many ways. In many areas, allowing natural
shoreline retreat and inundation will have an adverse effect on water quality.
Erosion of wetlands will increase turbidity. Saltwater will migrate upstream
in estuaries, endangering water supplies. Reduced discharge from upstream
impoundments will aggravate estuarine circulation problems and will enhance
saltwater intrusion. Some coastal areas, however, will benefit from increased
circulation of coastal waters. In many areas, rising water tables will inundate
septic tanks and leach into fields and hazardous waste sites, causing health
and eutrophication problems.

In most areas, holding back the sea will have an adverse effect on water
quality. Dredge and fill may create noxious conditions as dredged areas
stagnate. Dikes and levees will isolate wetlands and water bodies from adjacent
estuaries and will affect sedimentation rates and salinities. Tidal barriers
will enclose estuaries for increasing periods of time, thus impeding natural
circulation; estuarine salinities will be significantly affected, and residence
times for pollution will increase drastically.

INTRODUCTION

Responses to sea level rise can range from planned retreat from coastal
areas to increasingly more costly engineering solutions, including dredge and
fill, emplacement of tidal barriers, and construction of dikes and levees.
Retreat can leave natural terrains and pollutant sources exposed to leaching and
erosion, resulting in degradation of water quality. Ironically, many engineering
structures intended to protect against the ravages of the sea will cause problems
in water quality by modifying mixing and discharge rates.

209

Environmental Implications

RETREAT

The option of doing nothing in response to sea level rise will undoubtedly
be exercised in many areas of the world. In a few instances water quality will
improve compared to present conditions, but in most cases water quality will
suffer as a result.

EROSION OF WETLANDS AND LOWLANDS

Erosion of extensive wetlands will create additional turbidity in some
areas, with adverse effects on marine flora and fauna. For example, simulation
of conditions in Key Largo and the Everglades of southeastern Florida indicates
that a large area of mangrove swamp and freshwater marsh would be inundated and
eroded by a one-meter rise in sea level by the year 2100 (Figure 1). Even very
conservative estimates of erosion and transport of wetland soils suggest that
high turbidity would result, excluding seagrass from all but the shallowest

A"OW

B Drw iftrw N Daveloood it SuanP
%% Frestmarah IN Taltmersh A%@ Mangrcm.-=
0 Bamimho'Flat E3 Matoc I Dike

Figure 1. Key Largo and the Everglades, southeastern Florida; present conditions
and predicted conditions with a one-meter sea level rise by the year 2100, with
residential and commercial developments protected (Park et al. 1989).

waters and killing the coral reefs. Cessation of reef-building along the Florida
coast during the postglacial sea level rise probably occurred as a result of
similar erosion of soils on inundated lowlands (Lighty et al., 1978).

Many waste disposal sites will also be subject to erosion, especially if
they have been constructed above ground level (Flynn et al., 1984). Unless these
facilities are protected or moved, erosion will release toxic chemicals and other
hazardous materials into the coastal environment.

210

Park

IMPACTS ON ESTUARIES

Salinity

In response to sea level rise, saltwater in estuaries will migrate upstream
(Figure 2). This saltwater intrusion will displace coastal fisheries and
ecosystems, perhaps increasing shellfish grounds (Hekstra, 1986) but also
introducing predators (such as the oyster drill) that are excluded by lower
salinities (deSylva, 1986). It also will endanger municipal water intakes (Hull
and Titus, 1986). The problems will be aggravated by decreased average discharge
that can be expected for many rivers under conditions of climate change.
However, upstream saltwater intrusion may be ameliorated by adjusting river
channels to higher sea level by means of sedimentation (Goemans, 1986).

Upstream reservoirs could cause NU DW CNINITY, ORM RIWR
further problems with saltwater
migration by decreasing freshwater
discharge. However, controlled
releases of fresh water to coincide 6
5
with high tide levels, as practiced @s 4
now by many water basin authorities, 3
could help alleviate the problem. 2
Trapping of sediments in reservoirs
also will prevent adjustment of
channels and adjacent wetlands to sea 52 57 73 78 84 89 94 90 102 108 111 111 V
level rise, thereby perpetuating both RIVER MILE
saltwater migration and inundation IASE -,-T3-CM -.-250-CM
(Broadus et al., 1986). 1Figure 2. Distribution of chlorinity inI
Some coastal areas that now have the Delaware River, U.S.A., at present
higher or lower salinities due to and as a function of sea level rise
restricted exchange with the open (Hull and Titus 1986).
ocean will benefit from more normal
marine salinities as tidal prisms increase and as barrier islands and fringing
reefs are breached and inundated.

Turbidity and Sedimentation

Only a small fraction of sediment transported into estuaries reaches the
Continental Shelf. For example, 91% of the sediment transported into the upper
Chesapeake Bay is retained there (Meade, 1972a). Most of the coarser bed load
is deposited near the toe of the salt wedge that extends upstream beneath the
less dense freshwater wedge; sea level rise would cause this material to be
deposited farther upstream. Sedimentation of suspended particles occurs
initially near the turbidity maximum, which is just downstream from the toe of
the salt wedge (Meade, 1972b). The turbidity maximum would also move upstream
with sea level rise.

211

Environmental Implications

Increased Stagnation at Depth in Restricted Areas

In well-stratified coastal waters, deepening conditions may increase the
potential for stagnation of bottom waters and development of anoxic conditions.

IMPACTS ON GROUNDWATER

As of 1977, 21 coastal states in the United States had problems with
saltwater intrusion into aquifers, because of excessive pumping (Newport, 1977).
Saltwater intrusion will become a greater problem with sea level rise, especially
if coastal communities and farms are forced to rely more on groundwater as
surface water supplies become saline.

The Ghyben-Herzberg principle Grourw LeV*F
has been used to estimate the extent
of saltwater intrusion into
unconfined aquifers as a result of All
�@Iaa!ed Aet Ltval
sea I evel ri se (Kana et al . , 1984) . S Present sea Level
The saltwater-freshwater interface
below sea level is 40 times the Freshwater
System Before
freshwater head above sea level, and Sam Level FUse
the interface and head are assumed to
- - Freshwater System
shift accordingly with sea level rise Displaced By AN=1-
Sea Level Rise
(Figure 3). The horizontal L_
displacement has two components: x, Figure 3. Saltwater intrusion into an
which is a function of the slope, and unconfined coastal aquifer as a function
y, which is a function of sea level of sea level rise (modified from Mehta
rise. However, the principle assumes and Cushman 1989).
equilibrium conditions, which may not
be attained with substantial groundwater discharge and with rapid sea level rise;
the result is usually a worst-case estimate. For example, the saltwater front
in the Biscayne aquifer extends several miles seaward past where the Ghyben-
Herzberg principle predicts it should be (Lee and Cheng, 1974).

DREDGE AND FILL

One response that can be undertaken by individual property owners is to
dredge canals and use the dredge fill to raise individual properties. However,
these finger-fill canals can become anoxic with deepening water conditions. To
promote adequate mixing and aeration, the U.S. Environmental Protection Agency
(1975) has recommended that canal depth not exceed 1.2 to 1.8 m. If 4.0 mg/L
dissolved oxygen is taken as the minimum desirable concentration, even a 0.5-m
rise in sea level will cause a significant water quality problem (Figure 4).

212

Park

DIKES AND LEVEES
RDRIDA, ALW ITA
Dikes and levees are earthen
embankments constructed to prevent
flooding of lowland areas. By 6 -
isolating wetlands and water bodies 5
from normal exchange with estuaries 4
and rivers, they reduce sedimentation 3
rates and alter salinities. They 2
also prevent natural flushing of
pollutants. As the hydraulic head
increases with rising sea level, ......... .............. I
water tables will rise and seepage of 0.3 0.9 1.5 2.1 2.1 3.4 4A 4.6 5.2 5.0 6.4 7.0 1.6
saltwater will increase in areas
below sea level. This problem is
already affecting Dutch agricultural Figure 4. Relationship of dissolved
lands (Goemans, 1986; van Dam, 1986), oxygen to depth of fingerfill canals in
and substantial sea level rise would Florida (U.S. Environmental Protection
aggravate the problem further (Figure Agency 1975).
5).

0 mmiday

D25
MEM
050

Scheldt

A Present B Five-meter rise

Figure 5. Change in seepage of saltwater in the Netherlands with a five-meter
sea level rise (DeRonde, 1989).

213

Environmental Implications

TIDAL BARRIERS

Movable barriers are constructed across estuaries to prevent storm surges
from moving upstream; they also can be designed to ameliorate the effects of
tidal flooding associated with higher sea level. Barriers have been installed
to protect areas such as London, England; Osaka, Japan; Providence, Rhoda Island
(U.S.); and the Rhine Delta, the Netherlands. Barriers are currently being
planned to protect Venice, Italy, by sealing off the tidal inlets to Venice
Lagoon (Carter, 1987; Pirazzoli, 1987). The problem with such barriers is that
they impede circulation, thus affecting salinities and trapping pollutants.
Extensive studies of Venice Lagoon (Figures 6*and 7) have shown that water
qual i ty woul d be much worse under more 1 i mi ted exchange through the t i dal i nl ets;
algal blooms would increase due to eutrophication, and residence times of toxic
pollutants would also increase. However, the surface of the lagoon is inclined
to the southwest with the persistent Bora wind, which causes about a quarter of
the floods (Pirazzoli, 1987), and barriers could be operated to enhance
circulation due to that difference (Kej, personal communication, 1989).

F-7 .-4
a. .06/ .06
.0 .02

.02

2 0
3P

.04
N25 .06
.5 .08

.6 .0a

2 .06
4
2
W2 0 2 b;
9 Is
Figure 6. Simulated distribution of Figure 7. Simulated distribution of
ammonia in Venice Lagoon with tidal phytoplankton in Venice Lagoon with
exchange with the Adriatic Sea (Dejak tidal exchange with the Adriatic Sea
et al.,1987). (Dejak et al., 1987).

214

Park

CONCLUSIONS

If response strategies are ignored, water pollution is generally viewed as
a minor impact of sea level rise, compared with inundation, erosion, and
flooding. But strategies to protect dryland would have important impacts on
water quality. When viewed in conjunction with potential loss of natural
shorelines, one could conclude that the environmental implications of sea level
rise ultimately may, prove to be more important than the more obvious economic
impacts.

ACKNOWLEDGMENTS

This paper was prepared through Cooperative Agreement CR-816331-01-0 with
the U.S. Environmental Protection Agency; James G. Titus is the project monitor.
James Rogers and Paul van der Heijde reviewed the manuscript; their help is
appreciated.

BIBLIOGRAPHY

Broadus, J., J. Milliman, S. Edwards, D. Aubrey, and F. Gable. 1986. Rising
sea level and damming of rivers: Possible effects in Egypt and Bangladesh. In:
Effects of Changes in Stratospheric Ozone and Global Climate, Volume 4: Sea
Level Rise. J.G. Titus, ed. Washington, DC: U.S. Environmental Protection
Agency, pp. 165-189.

Carter, R.W.G. 1987. Man's response to sea-level change. In: Sea Surface
Studies: A Global View. R.J.N. Devoy, ed. London: Croom Helm, pp. 464-498.

de Ronde, J.G. 1989. Past and future sea level rise in the Netherlands. In:
Workshop on Sea Level Rise and Coastal Processes. A.J. Mehta, and R.M. Cushman,
eds. Washington, DC: U.S. Department of Energy, pp. 253-280.

Dejak, C., I.M. Lalatta, L. Meregalli, and G. Pecenik. 1987. Development of a
mathematical eutrophication model of the lagoon of Venice. Ecological Modelling
37:1-20.

DeSylva, D. 1986. Increased storms and estuarine salinity and other ecological
impacts of the greenhouse effect. In: Effects of Changes in Stratospheric
Ozone and Global Climate, Volume 4: Sea Level Rise. J.G. Titus, ed. Washington,
DC: U.S. Environmental Protection Agency, pp. 153-164.

Flynn, T.J., S.G. Walesh, J.G. Titus, and M.C. Barth. 1984. Implications of
sea level rise for hazardous waste sites in coastal floodplains. In: Greenhouse
Effect and Sea Level Rise. M.C. Bart, and J.G. Titus, eds. New York: Van
Nostrand Reinhold, pp. 271-294.

215

Environmental Implications

Goemans, T. 1986. The sea also rises: The ongoing dialogue of the Dutch with
the sea. In: Ef f ects of Changes i n Stratospheri c Ozone and Gl obal Cl i mate. J. G.
Titus, ed. Washington, DC: U.S. Environmental Protection Agency, pp. 47-56.

Hekstra, G.P. 1986. Will climatic changes flood the Netherlands? Effects on
Agriculture, land use and well-being. Ambio 15:316-326.

Hull, C.H.J., and J.G. Titus, eds. 1986. Greenhouse Effect, Sea Level Rise,
and Salinity in the Delaware Estuary. Trenton, NJ: Delaware Basin Commission.

Kana, T.W., J. Michel, M.O. Hayes, and J.R. Jensen. 1984. The physical impact
of sea level rise in the area of Charleston, South Carolina. In: Greenhouse
Effect and Sea Level Rise. M.C. Barth, and J.G. Titus, eds. New York: Van
Nostrand Reinhold, pp. 105-150.

Lee, C-H., and R.T. Cheng. 1974. On seawater encroachment in coastal aquifers.
Water Resources Research 10(5):1039-1043.

Lighty, R.G., I.G. MacIntyre, and R. Stuckenrath. 1978. Submerged early holocene
barrier reef south-east Florida shelf. Nature 276:59-60.

Mehta, A. J. , and R. M. Cushman, eds. 1989. Workshop on Sea Level Rise and Coastal
Processes. Washington, DC: U.S. Department of Energy, 289 pp.

Newport, B.D. 1977. Salt Water Intrusion in the United States. Ada, OK: U.S.
Environmental Protection Agency.

Park, R.A., M.S. Trehan, P.W. Mausel, and R.C. Howe. 1989. The effects of sea
level rise on U.S. coastal wetlands. In: The Potential Effects of Global Climate
Change on the United States: Appendix B - Sea Level Rise. J.B. Smith, and D.A.
Tirpak, eds. pp. 1-1-1-55.

Pirazzoli, P.A. 1987. Recent sea-level changes and related engineering problems
in the lagoon of Venice (Italy). Progress in Oceanography 18:323-346.

U.S. Environmental Protection Agency. 1975. Finger-fill canal studies Florida
and North Carolina. Athens, GA: U.S. Environmental Protection Agency, 427 pp.

Van Dam, J. C. 1986. Characterization of the interaction between groundwater
and surface water: salinity. In: Conjunctive Water Use. S.M. Gorelick, ed.
Wallingford, Oxfordshire, England: International Association of Hydrological
Sciences, pp. 165-179.

216

COASTAL MARINE FISHERY OPTIONS
IN THE EVENT OF A WORLDWIDE RISE IN SEA LEVEL

JOHN T. EVERETT AND EDWARD J. PASTULA
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
Silver Spring, Maryland

INTRODUCTION

Many stocks of marine finfish and shellfish throughout the world depend
on fertile coastal marsh and estuarine areas for either part or all of their
life cycle. With a worldwide rise of sea level of 0.5 to 1.0 meters by the
year 2050 (as assumed in this paper), these areas may undergo considerable
change and may eventually be replaced by new environmental regimes. Living
marine resources indigenous to these areas will have to adapt to the changing
conditions, migrate to more suitable waters, or simply die.

During these changes, the socioeconomic and perhaps political fabric
dependent on the harvest of these resources will also be in jeopardy. With
these possibilities in mind, governments will have to decide either to attempt
to protect important fisheries or to allow nature to take its course. If the
protection course is chosen, then options and strategies must be developed for
its implementation.

Habitats Threatened by Sea Level Rise

In the United States, about 70 percent of our fisheries depend on
estuaries for their existence (National Marine Fisheries Service Archives,
1989a). Worldwide, this figure is probably smaller but certainly significant.
There are, of course, regional variations. In the southeastern United States,
for example, about 90 percent of the fisheries are estuary dependent. In this
region, we have the most important U.S. fishery in terms of value -- shrimp
(Penaeus spp., $506 million) -- and in terms of volume -- menhaden (Brevoortia
spp., 946 million metric tons) (National Marine Fisheries Service, 1989b).
The sea level rise problem in the Southeast is complicated by subsidence of
the land in a large portion of the region. We are experiencing now the
problems that may occur on a more general basis around the world with a rise
in sea level. Those of us involved in a custodial role with living marine
resources have several concerns.

217

Environmental Implications

Marshes and Shallows for Habitat and Nutrition

A multitude of commercially and recreationally important species use the
fringing marshes and shallow waters for critical parts of their life cycle
(including reproduction, shelter, and foraging). We are becoming increasingly
aware of the great significance of these areas to marine resources. Many
species live in rather narrow bands along and through these coastal areas. If
sea level rise is rapid, new habitats will not be created by natural processes
in the quantities required to maintain healthy populations of many species
(Gardner, 1990).

Wetlands That Interact With the Marine Habitat

Further inland from the marshes are the wetlands and their rich and
diverse life, all of which interact with the marshes (Figure 1). Nutrients,
animal life, and waters are exchanged in an endless pattern. The health of
the wetlands is crucial to the health of the marine side of the equation. As
sea level rises, the areas occupied by the wetlands will be the primary source
of new marshes and shallow-water habitat.

Turtle-Nesting Beaches

Many species of sea turtles are recognized throughout the world as being
endangered or threatened with extinction (Endangered Species Act of 1973 (P.L.
93-205), as amended in 1988 (P.L. 100-478)). Many of their nesting beaches
have attributes that are also sought by mankind. As a result, many of the
existing beaches are fringed with buildings of various types. Many of these
structures represent significant economic investments. In addition, roads
throughout much of the world are built just landward of these beaches. With
even a small rise in sea level, significant additional stress will be placed
on turtle populations.

Haul Out and Pupping Beaches for Pinnipeds

Most pinnipeds are heavy users of beaches (Figure 2). As in the case of
turtles, there are often human investments just landward of the present
beaches. In addition, sea level rise will inundate some important habitats.
A very gradual rise in sea level probably would not present a major problem.
Perhaps the case involving pinnipeds is more regionally differentiated than
any of the other problem areas. Some species are quite isolated from interac-
tions with mankind, while others compete quite aggressively with people for
beach space.

WINNERS AND LOSERS

Short-Term Impacts

In the short term (10 to 100 years), it is possible to find both winners
and losers. As marshes flood, some shrimp will have improved their habitat,

218

Everett and Pastula

-;L-4

ArA*

Figure 1. Estuarine channel showing marsh grasses and boat access.

IVM

Figure 2. Female California sea lions with pups on a northwest U.S. beach.

219

EnvironmentV Imp7ications

and some fish will have more food as the marshes rot (Zimmerman et al., 1989).
However, it should be clear that these benefits are very transitory. With a
loss of their habitat as the marshes flood and die, the populations of these
animals will most likely plummet. These are not inconsequential losses. In
the United States, for example, our southeastern shrimp and menhaden fisheries
fall into this category.

Some species subsist on a narrow band along the shore. For example, some
clams and other shellfish live in quite narrowly defined niches in the marshes
and shallows. They will lose their habitats with any but the slowest rates of
sea level rise. As noted above, some important species of sea turtles are
particularly susceptible to losing their nesting beaches.

Long-Term Impacts

In the long term (beyond 100 years), if sea level rises very slowly and
land and property are not protected, there will be little impact on fisheries.
However, sea level rise may not be quite so slow, and people will most likely
protect their investments in property and farmland that line much of the
world's beaches, marshes, and wetlands. Given that significant protection
will be attempted to preserve valuable dryland, particularly in the absence in
many areas of knowledge of the importance and value of wet habitats,
estuarine-dependent species can be expected to suffer. Shrimp, sea turtles,
and coastal pelagic finfish may lose the most.

We have been quite unsuccessful in identifying the long-term winners.
Perhaps as we learn more about the interactions of fisheries' resources with
sea level rise, we will find some. However, we do not envision discovering
species that will significantly benefit over the long term.

As custodian of our nation's living marine resources, NOAA/National
Marine Fisheries Service argues constantly against those in government and in
the private sector who would add to investments in the coastal areas (National
Marine Fisheries Service, 1983-1989). We do not do this in anticipation of
sea level rise, but rather to slow the rate at which we are losing our coastal
wetlands and estuaries. We know that this is a difficult struggle, and we are
gravely concerned that those with investments along shores and wetlands will
be successful in protecting them regardless of the value of the fisheries
affected by protectionist actions. If sea level rises and the natural
succession of dryland to wetland, marsh, and shallow water is not allowed to
run its course, manyfisheries and some endangered species will pay a dear
price. This information on the importance of coastal habitats to continued
production of fisheries must be brought before coastal planners, engineers,
and government officials in as forceful and meaningful a manner as possible.
There are many acres of land suitable for farming and for cities. There is
relatively little available for coastal and estuarine habitat. This leads us
to the following thought:

220

Everett and Pastula

An acre of farmland is one of many.
An acre of marsh is one of a few.
Protection of farmland will disproportionately hurt fisheries.

FISHERIES OPTIONS

The following options were developed from a review of the current
literature, as well as our own thoughts and discussions on the subject, based
on the assumption of a 0.5- to 1.0-meter rise in sea level. For purposes of
this paper, the options have been placed in three groupings:
scientific/technical, economic, and sociological/political.

We also project that human and financial resources (HFR) to address
living marine resource (LMR) problems and opportunities throughout the world,
resulting from a rise in sea level, will be very scarce. Individual nations
may accord higher priority status, and use of scarce HFR, to more pressing
needs such as agricultural adjustments, population relocation, disaster
relief, transportation, etc. The only practical way to address the protection
and conservation of LMRs, many of which are highly mobile and transboundary,
is through the international pooling and allocation of HFRs.

To help in deciding how to allocate these fiscal resources, we have
ranked the options under each category according to what we consider would be
their value to society and the resource. In this regard, options were
assigned a value of High (H), Medium (M), or Low (L) according to their
importance relating to the protection, conservation, and use of the world's
living marine resources. The rankings were developed following discussion and
review with several senior fisheries scientists and administrators at the
headquarters of the U.S. National Marine Fisheries Service.

Scientific/Technical

(H) Advise decisionmakers engaged in the planning, construction, and
maintenance of water barriers about the needs of fisheries. Serious
attempts may be made to "Hollandize" certain parts of a country to regain
or supplement lost land as a result of flooding. Encourage the concept
of providing for new nursery grounds at a level possibly exceeding
preflood extent and values.

(H) Improve resource monitoring systems to provide current information on
changes in fishery habitats and populations in response to global warming
or to some other environmental change that may significantly alter the
"stability" of fishery resources. The information must be developed,
archived, and made readily accessible.

(H) Encourage development now of biological controls of agricultural pests
over chemical,means, and promote the use of rapidly degradable crop
growth chemicals to reduce land runoff pollution of estuarine, marsh, and
coastal areas conducive to fishery resources. Reduced land for

221

Environmental Implications

agricultural use may trigger efforts to drastically increase agricultural
production through more deliberate and extensive use of fertilizers and
other growth chemicals. Such development may substantially increase
their entry into fishery ecosytems.

(M) Promote the development of realistic models of the inshore, nearshore,
and offshore environment to assist in predicting environmental and
biological changes in these overlapping zones.

(M) Maintain the diversity of species by establishing preserves of suitable
habitat for species being harmed.

(L) Cooperatively develop State/Federal plans addressing anadromous and
catadromous fishery resources.

(L) Encourage development now of an early warning system to detect abnormal
pathogenic activity among fishery resources that may enter the human food
chain. Depending on the rate of change, a worldwide rise in sea level
may very well result in biological stress to existing and potentially new
fishery resources. Such stress may aggravate existing pathogenic, but
in-check or dormant, organisms to explode to epidemic proportions. LMR
populations may suffer irrevocable disaster, and some pathogens may find
their way into the human food chain. Some thought and prevention
planning should be given to this possibility, and early warning systems
to detect pathogenic abnormalities should be devised and monitored.

(L) Assist in development of different or new harvesting and processing
methods and techniques geared to different stocks and their distribution.

(L) Develop and establish federally funded and supported "Living Marine
Resources Banks" designed as repositories (cryogenic gene banks?) for the
continuance of species biologically important not only to.mankind but
also to their own survival and prosperity.

Economic

(H) Constrain further development in the coastal zone to avoid the likelihood
of defensive strategies to protect developed areas. The natural
succession needed by marine species will depend on an undefended
shoreline.

(H) Foster, possibly with economic incentives, mariculture to continue and
increase the supply of seafood as well as to supplement wild stocks, and
maintain populations of endangered and threatened species (e.g., turtles)
that may be affected by changes in nesting habitat, locale, and food
supply.

(M) Safeguard existing coastal mariculture capabilities of countries and
communities that heavily depend on mariculture for food and export
revenues.

222

Everett and Pastula

(L) Develop and establish a decisionmaking process for the sole purpose of
determining which fishery stocks (and support systems) should be and can
be "saved," as opposed to those that should be allowed to be at the mercy
of natural forces.

Sociological/Political

(H) Encourage and provide for education of the public and government sectors
about sea level predictions and how they should respond. It is important
that all people understand the situation and receive good advice on
proper courses of action.

(H) Continue mediation of potential conflicts between commercial and
recreational fishermen. Some problems will exist, but priorities and
species of concern may change. There may be more initial commercial
demand for fish protein as the supply of agricultural, dairy, and land-
produced meat products changes.

(H) Encourage the development, implementation, and enforcement of policies
designed to promote holistic commercial and recreational development of
newly created marsh, estuarine, and other coastal areas that may serve as
resource nursery and feeding grounds.

(H) Promote the concept of "world food security," as defined by the Food and
Agriculture Organization, but in terms of world fisheries exemplified by
the adequacy of fishery products, stability of fishery products, and
especially access by the world's populace to fishery products.

(H) Implement fishery management schemes to protect, conserve, and adequately
allocate offshore fishery stocks. There may be a shift from perceived
unstable inshore fisheries toward greater utility of more stable offshore
fisheries. Such a move would result in greater harvest pressure on
offshore stocks, possibly resulting in depletion of such stocks.

(M) Develop new fishery management methods, techniques, and plans to
accommodate the potential shift and relocation of fishery stocks in
primarily new estuarine and coastal areas. It is also very important to
keep stocks healthy so that they can be resilient in times of stress.

(M) Encourage and promote closer ties and alliances among fishery-oriented
government groups (domestic and international), private citizenry, and
commercial enterprises for the purpose of pooling talent and scarce
resources.

(L) Foster appropriate implementation of new regulations and the enactment of
new laws as may be necessary to manage the new fisheries regimes.

(L) Assist harvesters, processors, and users in adjusting to different and
new species and to the demands made on them.

223

Environmental Implications

(L) Encourage the streamlining of the current judicial process dealing with
environmental and LMR matters so that the focus of resulting litigation
will not "wither on the vine."

CONCLUSION

As custodian of our Nation's living marine resources, we are dedicated to
the protection, conservation and wise use of the animals that inhabit the
marine and estuarine environment, as well as their habitat. Government can
help conserve and manage fisheries that are of economic, sociological, and
political importance to our planet's inhabitants.

The ability of governments to take these actions depends both on the
availability of financing and on the importance these nations attribute to the
resources at risk. A cursory examination of the listed options reveals that
many of them would require massive expenditure to effect the option. It is
also evident that no single government can achieve even adequate protection of
its living marine resources and their habitat unless it is willing to
sacrifice other substantive resources to do so. Our observations indicate
that governments are often neither willing nor able to allocate scarce
resources to protect fisheries and their habitat.

We therefore conclude that if governments decide to protect their living
marine resources, they must collectively decide on fishery priorities and pool
together the scarce, necessary resources to produce the desired effect.

BIBLIOGRAPHY

Gardner, J. 1990. Reporting on research at Connecticut College. National
Fisherman 70(10):52.

National Marine Fisheries Service Archives. 1989a. Extrapolated information
from 1983 U.S. commercial fishing landings data. J. Chambers, National Marine
Fisheries Service, personal communication.

National Marine Fisheries Service. 1989b. Fisheries of the United States:
Current Fisheries Statistics. No. 8800. Silver Spring, MD: National Marine
Fisheries Service, p. v, ix.

National Marine Fisheries Service. 1983-1989. Habitat Conservation Program
Annual and Biannual Reports. Silver Spring, MD: National Marine Fisheries
Service.

Zimmerman, R., E. Klima, T. Mimnello, and J. Nance. 1989. Wetland losses and
fishery gains: a paradox in the northwestern Gulf of Mexico. Galveston, TX:
National Marine Fisheries Service, Southeast Fisheries Center (unpublished
manuscript).

224

IMPACT OF RESPONSE STRATEGIES ON DELTAS

JAMES G. TITUS
Office of Policy Analysis
U.S. Environmental Protection Agency
Washington, DC

The previous three papers have a common theme: protecting developed areas
from inundation and erosion usually upsets the coastal environment. In the case
of the open coast, Leatherman shows that seawalls and sea dikes can result in
the loss of natural beach and dune ecosystems; groins merely transfer the erosion
problem from one area to another; and even the environmentally preferred approach
of sand replenishment can hurt life on the inner continental shelf. Along
sheltered shores, bulkheads to stop erosion can result in wetlands loss, and Park
points out that tidal barriers to prevent flooding can cause pollutants to build
up.

In addition, dams built to counteract increased drought could limit the
freshwater flowing into estuaries, and thereby exacerbate salinity increases due
to sea level rise. Frequently, however, the dams are used to maintain riverflows
above a minimum level; hence they would often help to offset the salinity
increases. Finally, the construction of dikes and pumping systems to prevent
inundation due to sea level rise would cause groundwater to become salty.

The purpose of this note is to highlight the environmental impact of
response strategies on deltas, which fit broadly into three categories: river
dikes (levees); dams; and sea dikes.

RIVER DIKES

Deltas were created by the sediment washing down from the adjacent rivers.
Generally, the flood season brings sediments that elevate existing land and
create new land in areas that were formerly shallow water bodies. The size of
a delta tends toward an equilibrium equal to the volume of sediment supplied by
the river and wetland vegetation divided by the rate of relative sea level rise.'
Because the recently deposited deltaic muds tend to settle, the relative rate
of sea level rise in many deltas is 5 to 10 millimeters per year (compared with
the worldwide average of 1 to 2 millimeters per year). Without the sediment
supplied by the river, they would gradually disappear even without an accelerated
rise in sea level due to the greenhouse effect.

225

Environmental Implications

In the case of a delta with the equilibrium area and relative sea level
rise today of 5 mm per year, a 50-cm rise in sea level by 2100 would imply that
the sustainable area of the delta will be cut in half -- assuming that the
supplied sediment remains constant. But if sediment supplies are curtailed, the
delta could be almost completely lost. As Schroeder (North America, Volume 2)
discusses, Louisiana (United States) is losing 100 square kilometers of deltaic
wetlands to the sea largely because dikes (levees) along the Mississippi River
prevent it from overflowing its banks during floods and from providing sediment
to the delta; the sediment washes off the continental shelf instead.

There is a risk that a rise in sea level could encourage additional dikes.
Consider Bangladesh, half of which is regularly flooded. If sea level were
higher, the water levels in much of the country would be similarly higher, and
areas currently outside the floodplain would then be within it. As a result,
officials might decide to build dikes to protect a few key areas. The resulting
confinement of riverflow, however, would tend to increase the flooding of other
areas, which could lead them in turn to demand a dike. If this process
continued, large amounts of sediment eventually would be washing into deep waters
there as well.

As has already occurred in Louisiana, the dikes would accelerate the
conversion of wetlands to water and would lead to the inundation of dryland that
woul d otherwi se remai n above sea 1 evel . Because the annual river flooding
provides important nutrients, the dikes would also degrade the fertility of
deltaic farmland.

DAMS

Similar impacts could occur if changes in precipitation patterns lead to
the construction of more reservoirs. Dams block the sediment flowing down
rivers. Although the diversion of water reduces the average annual flow of
water, their impact on estuarine salinity during droughts (when it is most
critical) depends on whether water managers use the dams to maintain minimum
flows for navigation and environmental quality.

The Nile Delta has already seen the consequences of dam construction. The
delta has started to erode rapidly, and the sardine fishery was largely lost to
saltwater intrusion. Without the annual flooding, soil fertility is dropping
as well.

SEA DIKES: THE END@F THE NATURAL DELTA
Whether caused by dams, river dikes, or the natural consequences of sea
level rise, erosion and flooding may lead officials to conclude that it is
necessary to completely protect the delta with dikes and to place it under
artificial drainage. That is, they may decide that it is no longer desirable
for the area to be a delta. In many cases, the complete cultivation of an area
may have effectively accomplished this transition anyway.

226

Titus

Nevertheless, in Louisiana and other deltas with a mix of natural wetlands
and reclaimed lowlands, the environmental implications of such a decision would
be profound. Although it would be possible to maintain freshwater wetlands for
waterfowl, the saltwater wetlands would be lost, and the fisheries would shrink
to a "shell" of their former productivity.

Although coastal protection is expensive, the loss of land may be even more
expensive; consequently, even developing nations may be able to raise the
necessary funds. But it is an open question whether foreign donors would
actually be doing these nations a favor if they provide the necessary assistance.

1. We are referring only to an equilibrium total area. Deltas continually
change course, so the shoreline position is never in equilibrium; but apart from
the mathematical "catastrophes" of a change in river course, the total area
generally tends toward an equilibrium. This argument is analogous to the Bruun
rule approach: Continual changes in wave climate prevents the shore profile from
ever remaining at equilibrium, the concept of an equilibrium allows one to
calculate the average retreat of the shore for a rise in sea level or a given
input of sediment to the beach.

227

ENVIRONMENTAL IMPACTS OF ENCLOSURE DAMS
IN THE NETHERLANDS

J.G. DE RONDE
Ministry of Transport and Public Works, Rijkswaterstaat
Tidal Waters Division
P.O. Box 20907
The Hague, The Netherlands

INTRODUCTION

A big storm surge in 1916 caused great damage and land losses in the areas
around the Zuider Zee. As a result, the longest enclosure dam in the
Netherlands, the one enclosing the former Zuider Zee, was built in 1932 (see
Figure 1). An even more disastrous storm surge in 1953 was the catalyst for the
building of the so-called Delta Works, which were finished in 1986 with the
completion of the storm surge barrier of the Eastern Scheldt. During the
building of the Delta Works, three other estuaries were cut off from the sea.
This paper discusses the impacts of these enclosures.

THE IMPACTS OF THE ENCLOSURE OF THE FORMER ZUIDER ZEE

The enclosure of the former Zuider Zee caused a big change in the tidal and
storm conditions in the Wadden Sea area. The tidal range increased by roughly
50% -- e.g., at Harlingen it increased from 1.25 to 1.80 m. In addition, the
height of storm surges increased by roughly 20%. This meant that besides
building the dam itself, all the dikes in the western part of the Wadden Sea
needed raising.

Since the enclosure of the Zuider Zee, the morphological system required
about 30 to 40 years to reach more or less a new equilibrium (Misdorp et al.,
1989). After these 30 to 40 years, the changes have become smaller. To reach
a real equilibrium will probably take more than 100 years. Near the dam, the
currents decreased. But in other areas of the Wadden Sea, and especially in the
tidal inlets between the islands, the currents and tidal volumes increased,
causing an unbalance in the morphology of the area. The tidal gullies near the
dam have been filled up by sediments, while the cross-sectional areas of the

229

Environmental Implications

C=,;=

dOWADDE
SEA

-YSSEL FORMER
LAK ZUIDER SEA

VXX

Rhine

Meuse
4@r

++
0 50 10,Okm X

Figure 1. Map of the Netherlands showing the former Zuider Zee, now enclosed
and called the Wsel Lake.

tidal inlets have increased by about 15-20%. Due to this morphological change,
the tidal system in its turn has been changing as well, causing an extra increase
of the tidal range of about 5% over the last 50 years (Misdorp et al., 1989).

The enclosure and the increase in tidal range caused the loss of intertidal
and salt marsh area (about 1000 hectares of salt marsh were lost), which affected
the ecology of the area. In the long run, a small increase of intertidal and
marsh area may be expected (Dijkema, 1987). On the inside of the dam, the
impacts were greatest: a large salt intertidal system changed into a freshwater
lake. The largest negative impact was felt by the fishermen, who lost their
fishing grounds.

230

De Ronde

THE IMPACT OF THE DELTA WORKS

The impacts on Zeeland due to the Delta Works will be discussed in relation
to the water system going from north to south (see Figure 2). The impacts of
the storm surge barrier on the Hollansche IJssel will not be discussed; they may
be neglected. The Western Scheldt is not included because, owing to shipping
to Antwerp, this estuary will remain open.

The Haringvliet

This water system has been enclosed with a huge sluice complex. During high
discharges of the Rhine and Meuse Rivers, most of the water has to be discharged
via the Haringvliet to the North Sea. The system changed from a brackish tidal
estuary to a more or less stagnant freshwater lake. The present tidal range is
less than 20 cm; greater water level variations are caused by high river
discharges.

At present, an unforeseen impact has given cause for great concern. During
the planning of the Delta Works, pollution was not yet of much concern. However,
today, sediments of the Rhine, strongly polluted with heavy metals, largely
settle on the bottom of the Haringvliet. Plans are being developed to clear
these sediments at huge costs. However, this effort will be useful only if the
river's future sediments become cleaner as well.

ROTTERDAM
NEW WATERWAY

HARINGVLIET SLUICES

BROUWERS DAM 09

STORM -
SURGE BARRIER

FRESH WATER

Figure 2. Map of the delta area of the Netherlands.

231

Environmental Implications

This unforeseen problem would not have occurred if the Haringvliet had
remained open; the sediments would have been transported into the North Sea and
would have settled in sedimentary areas. At present, officials are discussing
reopening the sluices, and closing them only during a storm surge. Owing to
these pollution problems, the impact of the enclosure on ecology is rather large,
and the system was more valuable in an ecological sense in the past.

The Grevelingen

The Grevelingen Lake was planned to be a freshwater lake after enclosure
to supply freshwater to the agricultural areas of the islands north and south
of it. At the time the dam was completed (1972), the ecological value of such
a freshwater lake as compared with that of a saltwater lake already was
questioned, and the lake was temporarily left marine. Despite a heavy protest
from the farmers, it was decided, many years later, to leave the lake marine.

In the beginning, seawater was let in and out only through sluices in the
Brouwers Dam on the sea side of the lake. It appeared that this strategy caused
stratification, accompanied by anoxia. This unforeseen problem was solved by
making another sluice on the eastern end of the lake. Now seawater can be taken
in from the Eastern Scheldt and can be discharged via the other sluices to the
North Sea. With this strategy, stratification no longer occurs. Today, the lake
has a very high ecological value due to the rarity of an unpolluted, clean,
saltwater lake. The lake enjoys a great number of different species of birds,
fish, plants, and especially seagrasses (Zostera). Even the economic value of
the lake is important because of high production of oysters and mussels, which
was not expected at all.

The Eastern Scheldt

In 1958, part of the plan for the Delta Works was to separate the Eastern
Scheldt completely from the sea and to make a freshwater lake of it. After the
closure of the Haringvliet and Grevelingen in 1972, the political pressure to
preserve the Eastern Scheldt as a marine environment grew so strong that the
Dutch government ordered a further study. The study advised against closing the
Eastern Scheldt, and in 1976 the government decided to build a storm-surge
barrier, which was completed in 1986. To preserve the valuable ecosystem and
the oyster and mussel nurseries in the area and to reduce the length of sea dikes
by 150 km, the government decided to spend an additional 2 billion guilders (I
billion U.S. dollars) on the Delta Plan.

Still, the storm-surge barrier together with the necessary extra enclosure
dams at the end of the estuary had some impacts on the environment. The tidal
range in the estuary decreased by 10-15% (the average tidal range is about 3 m).
The tidal volume decreased about 30%. Because of the extra enclosure dams and
the decrease in tidal range, roughly 30% (6,400 hectares) of the intertidal areas
and 65% (1,150 hectares) of the salt marsh areas were lost. Of the remaining
intertidal areas (11,000 hectares), another 1,400 hectares will be lost in the
next 30 years, as a result of the morphological changes caused by reduction of
the tides (Kohsiek et al., 1987).

232

De Ronde

These losses of intertidal and salt marsh areas have destroyed a large
feeding area for birds. Up until now, the numbers of birds have not decreased.
Although the birds can move to another place like the Western Scheldt, they have
to stay in the delta area. What will happen in the long run is not known. In
contrast, the mussel nurseries were able to move to other areas and production
remained the same. In fact, future production might even increase because of
lower water velocities.

Lake Veerse

The first estuary to be enclosed was the smallest one (Lake Veerse in 1961).
The plan was to make it a freshwater lake that would be flushed through with
freshwater via a fresh Eastern Scheldt.

At present, with a saltwater regime in the Eastern Scheldt, the water in
Lake Veerse is still brackish, with a rather low ecological value. As a water
supply for agriculture, the salt concentration of the water is too high. At the
moment, the possibility of making the lake saltwater again is being discussed.
To get a healthy saltwater ecological system, the lake needs to be flushed with
saltwater (a lesson learned from the Grevelingen lake). To make flushing
possible, a sluice has to be built in the Veerse Dam. Up until now, this
decision has not been made.

The Outer Delta Area

The impacts of the enclosures on the sea side of the delta are mainly
morphological. Tidal ranges and storm surge levels increased only locally near
the enclosures. Near the Eastern Scheldt storm surge barrier, the level of a
design storm surge, with a return time of 4,000 years, is increased by about 40
Cm. At greater distances (more than 30 km), changes are less than a few
centimeters.

The morphological changes are quite noticeable, especially in front of the
Grevelingen and Haringvliet, because of the changing tidal currents (Kohsiek,
1988). Along the shore, large sandbars developed, which started to migrate
landward and to increase in height. After about 10 years, the height of the
sandbars reached the intertidal zone, after which they stabilized at about -0.5
m below mean sea level.

The further development of this area into a more lagoon-like system has been
predicted by some experts. We must wait and see whether this will be the case,
and if so, how long it will take.

BIBLIOGRAPHY

Dijkema, K.S. 1987. Changes in salt-marsh area in the Netherlands Wadden Sea
after 1600. In: Vegetation Between Land and Sea. A.H.L. Huiskes et al., eds.
Amsterdam: Dr. W. Junk Publishers.

233

Environmental Implications

Kohsiek, L.H.M., J.P.M. Mulder, T. Louters, and F. Berben. 1987. Be
Oosterschelde naar een nieuw onderwaterlandschap. GWAO 87.029. The Hague:
Rijkswaterstaat, Tidal Waters Division (in Dutch).

Kohsiek, L.H.M. 1988. Reworking of former ebb-tidal deltas into large longshore
bars following the artificial closure of tidal inlets in the southwest of the
Netherlands. In: Tide-Influenced Sedimentary Environments and Facies. P.L.
de Boer et al., eds. -Reidel Publishing Company.

Misdorp, R., F. Steyaert, J.G. de Ronde, and F. Hallie. 1989. Monitoring
Morphological Developments of the Western part of the Dutch Wadden Sea.
Proceedings of the 6th International Wadden Sea Symposium List/Sylt (in press).

234

LEGAL AND INSTITUTIONAL
IMPLICATIONS

INTERNATIONAL LEGAL IMPLICATIONS OF
COASTAL ADJUSTMENTS UNDER SEA LEVEL RISE:
ACTIVE OR PASSIVE POLICY RESPONSES?

DAVID FREESTONE and JOHN PETHICK
Institute of Estuarine and Coastal Studies
University of Hull
Hull, United Kingdom

ABSTRACT

A rise in sea level would inundate lowlands, marshes, and mangroves, alter
erosion processes, and, in some areas, change tidal ranges. This paper examines
the legal issues resulting from these impacts, which include the effect of tidal
changes on the delimitation of coastal and maritime zones resulting from changes
in high tide (for coastal zone jurisdiction) and low tide lines (for maritime
zone baselines) and the implication of inundation of coastal areas. Various
active and passive strategies are compared in light of case studies of coastal
zone legislation and the law of the sea regime.

The paper also considers the international law implications of particular
national strategies -- such as building sea walls -- which are likely to
exacerbate the impacts on neighboring states, and considers the role of
international institutions in the coordination of national responses.

The paper concludes with an assessment of the active or passive policy
approaches for managing. Certain changes may best be met with inactivity (the
passive approach), while others will require immediate action and coordination
(the active approach).

INTRODUCTION

In a workshop on policy options for coastal management in response to sea
level rise, there must be an inevitable tendency to concentrate on national
options and, in a legal context, national law. The purpose of this paper,
however, is to explore some of the implications under international law of
climate change and sea level rise and to outline a number of restraints that
international law imposes or might impose on the range of policy options
available and the possible role it might play in the coordination of options.

237

Lega7-and Institutiona7 Imp7ications

Two main themes emerge. The first is the problem of maritime boundaries
that are defined on the assumption of a stationary coastline. The necessity for
their redefinition during a period of rapidly rising sea level requires careful
consideration. The second theme concerns the management difficulties that will
occur when coastlines change. Their management will require cooperative efforts
internationally as well as intranationally. For both sets of problems, there
are two distinct approaches: (1) take a passive approach and merely react to
the changes as they are imposed upon our coasts, or (2) take a pro-active stance
and consider how to anticipate and counter the most damaging of the changes about
to take pl ace. The paper concludes with a consideration of the extent of
international law obligations to cooperate in the face of rising sea levels.

SEA LEVEL RISE AND MARITIME BOUNDARIES

The first and most obvious effect that sea level rise will have is on high-
and low-water marks (HWMs and LWMs). Both of these may have legal significance,
but under international law, the LWM has particular significance. Article 5 of
the 1982 Law of the Sea Convention' (LOSQ, which is taken to represent customary
international law on the subject provides that:

the normal baseline for measuring the breadth of the territorial
i s the 1 ow water 1 i ne al ong the coast as marked on 1 arge scal e
charts officially recognized by the coastal state.

This baseline may depart from the low-water mark for a number of reasons
(the presence of bays, deeply indented coastlines, fringes of islands, etc.),
but the significance of the baseline is that the seaward limit of other maritime
zones are measured from it.' The use of the low-water mark generally ensures
that the maximum maritime area is included within the zone. By contrast,
national laws on coastal zone jurisdiction vary, but in the United Kingdom and
many other common law states, the high-water mark is generally taken to
represent the seaward limit of the jurisdiction of local authorities.' Although
the intertidal regions is still part of the state, in the UK this generally
comes under the jurisdiction of the Crown Commissioners.

Crudely put, rises, or indeed any changes, in sea level that affect high-
and low-water marks will obviously have a "knock-on" effect on the measurement
of jurisdictional zones. If the low-water mark advances landward, then because

'UN Doc A/CONF, 62/122; 21 International Legal Materials (ILM) 1261 (1982)

2i e., territorial sea, Article 3 LOSC; contiguous zone, Article 33(2);
exclusive economic zone, Article 57; and in some situations even the continental
shelf, Article 76(l).

30ther systems, for example Belgium, use the LWM as the limit of their local
jurisdictions.

238

Freestone and Pethick

all maritime zones are measured from that baseline, the outward limits of
maritime zones will similarly move landward, and the coastal state's maritime
zone limits will shrink proportionately. Where a broad coastline transgresses
rapidly, as in the case of areas of Bangladesh being eroded at up to 200 m per
year (Stoddart and Pethick, 1984), the cumulative effect could be quite
substantial: in this case, over 60 km' per year of the maritime zones. In fact
Article 7(2) LOSC contains a provision -- derived from the proposal initiated
by Bangladesh, which was concerned by the particular problems of constant
erosion and deposition at the mouth of the Brahmaputra 4 __ permitting, in
restricted circumstances, a straight baseline to be maintained, notwithstanding
the movement of the actual coast:

Where because of the presence of a delta and other natural conditions
the coastline is highly unstable, the appropriate points [i.e., for
straight baselines] may be selected along the furthest seaward extent
of the low-water line and, notwithstanding the subsequent regression
[sic) of the low-water line, the straight baseline shall remain
effective until changed by the coastal state in accordance with this
Convention.

Although, as Prescott (1989) points out, this was drafted for specific
circumstances, there is a risk that in the context of sea level rise it will be
used more widely than is legitimate under the LOSC regime.

Baseline movement will not normally (see Article 76 LOSC) affect the limit
of continental shelf claims that may extend to the edge of a continental margin.
However, it could have important economic effects on equidistance lines, which
may be significant in areas where boundaries have still to be settled, in that
hydrocarbon resources may move over a median line. It may also mean the
inundation of small islets or rocks that are currently used, or claimed, as
basepoints for maritime zones, such as the tiny islet of Aves in the eastern
Caribbean basin (see Freestone, 1989). Although the coral around atoll islands
might be able to keep pace with a gradual rise in sea level, it is unlikely that
the atoll islands themselves would receive enough sediment to keep pace,
although other atoll islands might be created.

Obstacles to Defining Maritime Boundaries

Once signed, maritime boundary agreements belong to that class of treaty
whose validity is not affected by subsequent fundamental changes in
circumstances.' Nevertheless, some treaties do use moving concepts, such as the

4A/CONF/62/C2/L7

'1969 Vienna Convention on the Law of Treaties, 8 ILM 679 (1969) Article
62(2)(a).

239

Legal and Institutional Implications
thalweg,' which may be considerably affected. In the more than 300 maritime
areas where boundaries have yet to be agreed on (Blake, 1987), changes in
baselines could have a significant effect on the negotiating position of the
parties. The parties are still influenced by equidistance lines, even though
they are enjoined by the LOSC Articles 74 and 83 simply to reach "an equitable
solution."

The horizontal magnitude of baseline changes, of course, will depend
initially upon the slope of the nearshore zone (Aurrecoechea and Pethick, 1986).
The North Sea -- where all the seabed boundaries have been agreed -- presents
an interesting theoretical model of possible movements of baselines and
equidistance lines. In the case of nations surrounding the North Sea, such
nearshore slopes can vary over wide ranges. Thus, the steep nearshore slopes
of Norway and Scotland contrast with those of the Wash embayment in eastern
England, where the nearshore slopes of 1:5000 mean that a 1-m rise in sea level
would shift the low-tide mark 5 km toward the present coastline of the United
Kingdom. Assuming a conservative average sea level rise of I mm per year, this
means a potential landward movement of the low-water mark of 5 m per year. Such
a rapidly changing coastline creates major problems in the definition of the
maritime boundary. It is clearly impossible to react continuously to such a
rapid movement of the natural boundary. A form of episodic adjustment of the
legal boundary to the natural movement of the coast again poses many problems,
including the most difficult one of predicting the future development of that
rate of sea level rise. Ignoring the departure of the low-water mark from the
legal baseline -- which is therefore regarded as fixed before sea level rise
-- is a possibility that may be welcomed by nations that would lose territorial
areas as a consequence, but not by those that may gain areas.

The possibility of an unequal or asymmetric shift in the position of the
equidistance line, so that some nations lose while others may gain territorial
advantage, is one that must be considered carefully. In the case of nations
facing each other across an intervening sea, such an outcome is quite feasible.
Thus, in the southern North Sea, nearshore slopes on the western seaboard, such
as those extending seaward from the mouth of the Thames, can be as low as
1:2000, while those on the eastern seaboard are steeper, 1:1000 off the Ooster
Schelde, for example. In this case, the shift in the baselines on opposite
coastlines due to a rise in sea level would be asymmetric and would cause a
shift of the true equidistance line toward the coast of the United Kingdom.

It must be realized, nevertheless, that such rigidly geometric calculations
do not necessarily apply to the dynamic shoreline under a rising sea level. The
parallel movements of low tide and high tide, for example, are possible only if
no sediment moves and if tidal range itself remains constant. Sediment
redistribution under a rising sea level is discussed later in this paper, but
here we may examine the complexities introduced into predictions of baseline
movement due to changes in tidal range produced by an increase in water depth.

'A possibly controversial example would be the 1975 Iran/Iraq treaty on the
Sh'at al Arab.

240

Freestone and Pethick

In the North Sea, for example, the slight increase in'sea level over the past
20 years may have been responsible for the observed increase in tidal range on
the coast of Germany, as shown by the Cuxhaven tidal gauge. Tidal range at a
shoreline is related to distance from the "amphidromic" point of the. tidal
system. I t may be that as sea level increases in the North Sea, so the
amphidromic point shifts slightly toward the west, which would cause a decrease
in tidal range on the coast of the United Kingdom and a commensurate increase
on the coast of the Federal Republic of Germany. The observed change at
Cuxhaven over the past 20 years has been on the order of a 30-cm increase in
tidal range. The magnitude of this change is greater than that of the sea level
rise, and thus movement of the low-water mark on this coast may actually be
seaward under a rising sea level while, on the toast of the United Kingdom, low
water would move more rapidly landward than mean water level.

Policy Options for Maritime Boundaries

Such discrepancies in the movement of the low-water mark boundary under a
rising sea level may lead to a move for redelineation of baselines -- a matter
primarily for the coastal state (see Article 5, above).' Prescott (1989) has
pointed out that this might present two policy options: (1) the active option
-- continuously updating the charts, and (2) the passive option -- leaving the
charts alone. Apart from the expense of the active option, significant
particularly for small developing countries (who might be the most affected
relatively), such action might be seen as the unilateral abrogation of existing
maritime areas, and hence, might be politically undesirable. The passive
option, however, is dangerous. As we have seen, international law simply
requires that the low-water mark be marked on "large scale charts officially
recognized by the coastal State." There is no requirement that these be
specifically produced for baseline delineation -- and, indeed, they are not.
The charts used are designed primarily for navigation. Hence, charts left
unchanged for political reasons at a time when important coastal
geomorphological change's are under way could be extremely hazardous. Or we
could see the widespread evolution of baseline maps (similar to those produced
by archipelagic states) simply marking the low-water mark, which is then omitted
from other charts. Prescott (1985) has already indicated the degree to which
Article 7 LOSC has been abused by state practices; sea level rise could
exacerbate this divisive tendency.

COASTLINE ADJUSTMENTS TO SEA LEVEL CHANGE

The relative stability of sea level over the past few hundred years has
led to a belief in the permanence of the coastlines of the world. Acting on
such an assumption, people have developed a complex physical and institutional
infrastructure which will have to be reappraised in view of the predicted sea
level rise. In this section, we examine two aspects of this reappraisal.

'Apart from delineation of the outer edge of the continental margin (which
for those bound by the LOSC regime may require some exchange with the Commission
established under Article 76(8)).

241

Legal and Institutional Implications

First, the role of the coast as a physical buffer between land and sea has
resulted in an equilibrium configuration to which we have in turn adjusted. Sea
level rise will initiate a series of changes that will"eVentually lead to the
attainment of a new equilibrium -- but only if we are cipable of allowing such
changes to take place. The difficulties this may pose'for our industrial and
social infrastructure and the international cooperation heeded to allow changes
across political boundaries are discussed.

Second, we examine the problems facing our Use of the coast for its
intrinsic value -- for its ecological and recreational.`si@nificance. Here the
complex existing network of international obligations establishing nature
reserves will need to be borne in mind when responding to changes and losses of
habitat under a rising sea level.

Physical Factors

The response of the coastline to sea level changes is not passive. The
coast is a dynamic landform that in most cases has achieved 'a form of quasi-
equilibrium with its wave and current environment. Changes' in this wave climate
or variations in nearshore currents introduced by new,warter depths mean that the
equilibrium is destroyed and that nature will initiate 'adjustments that will
eventually reattain the equilibrium. Although the range of geomorphological
adjustments to sea level rise may be extremely wide, we'may consider them here
under two headings: vertical adjustments and horizontal @adjustments.

Vertical Adjustments: The Coastal Profile

In the simplest case of a rise in mean sea ' level accompanied by a
commensurate rise in the high- and low-water marks, theire-i's some agreement that
the equilibrium shoreline that existed before the rise will move landward and
upward, thus keeping pace with the rise in mean water'level .@ Such a vertical
translation in profile was predicted by Bruun (1962); and the hypothesis that
erosion of the upper shoreline will be accompanied by deposition of the eroded
sediment in the lower shore is now known as the Bruun' Rule (Figure 1).

too level after rise
EROSION

sea b*d of ter
ePOSITION:.:., sea loveirise

Initial sea bed

Figure 1. Adjustments of the vertical shore profile to sea level rise (after
Bruun, 1962). (See Titus, Problem Identification for additional discussion.)
242

Freestone and Pethick

Although many authorities have questioned the details of the hypothesis
(e.g., Dean, 1987), the general pattern of a shoreline keeping pace with sea
level rise is a reasonable one. It does depend, however, on the free exchange
of sediment between upper erosion and lower deposition zones. As Pethick (1989)
has pointed out, such a free interchange will be actively suppressed by local
attempts to prevent upper shoreline erosion. Bulkheads and seawalls will
prevent sediment being made available for readjustments of the shore, and thus
a state of permanent disequilibrium will be forced on the shore profile.

Horizontal Adjustments: The Coastal Plain

A more complex and as yet unexplored aspect of coastal response to sea
level rise is the tendency for coasts to adjust their plan or horizontal
configuration to the new water level. These horizontal adjustments will be
caused by the re-orientation of the wave approach angles at the shore due to a
change in wave refraction. Waves refract or bend in shallow water so that their
crests tend to become parallel to the bottom contours. The refracted wave crest
then meets the shore at a more or less oblique angle which sets up a longshore
current whose velocity is directly proportional to the wave approach angle.
Such currents create longshore sediment movements along the coast, which cause
adjustments in its orientation. An equilibrium is eventually reached when the
shore becomes parallel to the refracted wave crests (for example, see Komar,
1976).

An increase in mean water depth caused by sea level rise will disturb this
longshore equilibrium. Waves will begin to retract closer to the shore in the
deeper water conditions and will meet the shore at an increased angle. This
will increase the velocity of the longshore current and set up movements of
sediment that eventually will alter the coastline's orientation and thus
establish a new equilibrium. The horizontal movement of sediment here can be
seen as directly analogous to the vertical movement of sediment described above
for the Bruun Rule. The difference from the point of view of policy adoption,
however, is that such horizontal movements of sediment may occur across national
boundaries, whereas the vertical movements are confined to local jurisdictions.

International Implications

Such vertical and horizontal changes in the coastline must be taken into
account in any measured response to the problem of rising sea level. It is
important for national authorities. When developing their policy responses to
such rises, national authorities need to understand that they should not make
their decisions in isolation. In areas such as the southern North Sea or East
Africa, where a number of states lie opposite or adjacent to each other with
coastal frontages on a single sea, the strategy adopted by one state may have
a considerable impact on neighboring states. Indeed, some policy options may
even exacerbate the problems of neighbors.

The example of the Fresian Island coast of the southern North Sea may be
cited here to illustrate the possible problems. This coast cuts across the
national boundary between the Netherlands and Germany. Figure 2 demonstrates

243

Legal and Institutional Implications

North Wesierly wave,
6 soc period
- - - wave refraction under
present sea level 4if-
wave refraction assurning
a 4-3m rise in sea level

ADMIRALTY CHART
SATHYMETRY

below L.W. M.
L, W. PA. - 10 rn

A. Elbe

. ..........
. . . . . . . . . . . . . . . . .

..... Coastal cUrr nt:
1.1 M/s
sent velocity
pre
assum
ing+3m rise in U.9;vn
Soo level velocity 1.96M S

+ G E R M A N Y
NETHERLANDS +

0 30

Figure 2. Changes in wave refraction and coastal longshore currents on the
Fresian Island coast due to a sea level rise.

that wave refraction in the new water depth will be less marked than previously,
so that wave approach angle at the shore will be increased. The result will be
a dramatic increase in longshore velocity. A 3-m-high wave, for example, would
generate a current of I m/s at present, but this would be increased to 1.9 m/s
under the new sea level regime. Figure 2 indicates that the effect would be to
increase sediment transport eastward along the coast of the Netherlands toward
the Federal Republic of Germany. These sediments, derived from erosion of the
foreshore of the Netherlands, would accumulate along the German coast between
the Elbe and Weser Rivers, eventually causing a reorientation of the whole
coastline and equilibrium. The immediate response, however, would be the loss
of the foreshore of the extremely vulnerable Dutch Fresian Islands, whereas the
marshes and mudflats of the Jade Bay and the Weser Estuary would be provided
with an abundance of sediment and would thus perhaps manage to accrete in pace
with the rising sea level (see also Nummedal and Penland, 1981). In such a

244

Freestone and Pethick

case, were the Netherlands to respond by strengthening shoreline def enses
against coastal erosion and by actively preventing the eastward movement of
sediment using groins or similar constructions, such action would both deny the
Federal Republic of Germany of sediment necessary for the maintenance of the
country's coastal marshes under a rising sea level and, more important, in the
long term would prevent any return of the whole coastline to an equilibrium
orientation.

Similar arguments apply to many of the coastlines of the world. An example
recently investigated by one of the authors (JP) is that of the East African
coast, which cuts across a number of national boundaries. Advance warning of
a major reorientation of this coast may be seen in the Rufiji Delta in Tanzania,
where the deltaic sediments are extremely sensitive to any change in wave
climate, and where a counter-clockwise swing of the entire coast has already
resulted in the erosion of up to 10 km of mangrove in the north of the delta and
the deposition of a 2-km-wide margin of mangrove in the south. Such
a coastal change may be an indicator of a more general change along this East
African coast, with profound implications for the neighboring states. Should
erosion of cliff coasts here be allowed to continue so that the more vulnerable
low-lying mangrove coast can benefit from the input of sediments derived from
this erosion and perhaps keep its head above water? Or would it be more
economic to prevent erosion of the cliff areas and allow the mangrove regions
to drown? Such decisions may only be taken in the light of a much more
extensive knowledge of the interactions between erosive and depositional areas
of the coastline and also of the relative economic outcome of either policy.

Intranational Implications

The international implications of such coastline reorientations are matched
by intranational ones. Thus, along the coast of eastern England there has been
a recent attempt to protect the Humberside cliffed coast from erosion that has
continued at a rate of 2 m per year throughout historic times. This erosion,
however, is one of the major sources of sediment in the southern North Sea
(McCave, 1987). As such, it is vital to saltmarsh areas lying immediately south
of the Humberside coast in the Wash. Denied such sediments, these salt marshes
would be unable to respond to sea level rise by accretion of their surfaces.
Their loss would have profound implications to the stability of the sea
embankments that lie immediately inland of the marshes and prevent enormous
areas of East Anglia from flooding.

Thus, the proposal to prevent the erosion of these cliffs has
understandably met with some opposition from those responsible for preventing
flooding in the Anglian region. The problem, however, has perhaps even wider
implications because resultant current directions in the southern North Sea
indicate that sediment derived from the erosion of this section of the coast of
eastern England feeds the pool of sediment in the North Sea. This sediment pool
is then available for the maintenance of the Dutch and German salt marshes. In
the face of a rapidly rising sea level, any diminution of input into this
sediment pool must be viewed with alarm by all nations bordering on the North
Sea.

245

Legal and Institutional Imp7ications

Ecological Factors

The building of artificial defenses w0uld.-have a radical effect on
ecologically important intertidal areas* mudflats, mangroves, and other
wetlands, many of which are protected by international treaty as well as by
national law. Defenses built landward of them would be highly likely to result
in their loss, while to barricade them (an unlikely option in any event because
of the cost) would entirely change their ecological character.
There now exists an increasingly sophisticated.ndtwork of wetland and other
coastal areas protected by both national- law-. and international treaties --
e.g., the Ramsar, Bonn, and Berne Convenflons.apd other regional treaties. The
wording of these conventions varies,.- "The Ramsar Convention on Wetlands of
International Importance especially as.Mildfowl. Habitat i 's purely hortatory in
tone, simply requiring the parties to "promote* the establishment of reserves
and inform an international commission about changes -in'the ecological character
of listed sites (for a list of sites, see PANSAR., 1987)." The Bonn Convention
of 19799 depends on the conclusion of further -agreements. The 1979 European
Berne Convention on the Conservation of European Wildlife and Habitat," which
came into force on June 1, 1982, Article'.4 requires contracting parties to:

take appropriate and necessary legislative and administrative measures
to ensure the conservation of habitats,. and 'the conservation of
endangered natural habitats (Article 4(1)) [as well as to give]
special attention to the protection of areas that are of importance
for migratory species [specified in the Annexes] and ire appropriately
situated in relation to migration 'routes, as wintering, staging,
feeding, and molting areas (Article 4(3)), .
Of particular interest to the matter in hand is the obligation on parties:

in their planning and development policy [to] have regard to the
conservation requirements of the areas protected... so as to avoid or
minimize as far as possible any deterioration of such areas (Article
4(2)).

8For text, see Lyster (1985) pp. 411-427.
9For text, see Lyster (1985) pp. 4216441.
"For text, see Lyster (1985) pp. 428,4410!.,

246

Freestone and Pethick

Similar obligations are undertaken in other regional treaties." Among the
most rigorous of these are the obligations of the 1979 EEC Directive on the
Conservation of Wild Birds Council Directive 12:

to take measureg-to`preserv6, maintain, or re-establish a sufficient
diversity and area 'of,'fiabitats*for all species of wild birds naturally
occurring in their territories. -(Article 3(1))

Such measures woul'd`ibcl-ud6 not:only the establishment of protected areas,
but also "upkeep and"min"Ageme'nt in accordance with the ecological needs of
habitats inside and outsIde the protected zones (Article 3(2))." This is no
empty undertaking. As we disc'Uss later in this paper, a case currently pending
before the European Court.'6f Justice concerns possible unlawful development of
such an area.
It seems clear, 'iherefore, that ih.planning responses to sea level rise,
national authorities (p'articularly,, but not exclusively, European authorities)
wi 11 need to bear in m1nd. their@ exi'sting binding legal obligations under
international law to ma6ta'in wildl-ife.habitats in coastal regions.
Policy Options for CoAstal Adjustments

The geomorphologi.cal adjustments to rising sea level outlined above
indicate that an im_agfna't1ve* 'and cooperative management structure will be
required in order to m1fi'imize the effects on coastal states. Both active and
passive policy options'are open to us.@

An Active Response: Bulkhead Policy

The arguments and examples developed above show that in many cases the
building of preventative bi@lkheads in the face of increased coastal erosion may
have deleterious results., At A local level, they inhibit the vertical response
of the coastal profile to the change in water level, thus maintaining the coast
in a state of disequilibri 'um with the co 'nsequent necessity for maintenance of
expensive shore defensds and drainage' provision. At an international level,
unilateral action by one state may have considerable effects on it neighbors.
For example, a bulkhead policy by one state that seeks to preserve the current
coastal status quo may seriously exacerbate the problems faced by adjacent
neighbors.

"1982 Geneva Protocol concerning Mediterranean Specially Protected Areas
-- see Article 3, for text see Sand (1988) pp. 37-44; 1985 Nairobi Protocol
concerning Protected Areas and Wild Fauna and Flora in the Eastern African region
- see Article 8, for text see Sand (1989), pp. 171-184; and the Draft Protocol
on Specially Protected Areas and Wildlife in the Wilder Caribbean -- due for
final consideration in January 1990.-
12 79/409/EEC, Official Journal. L10.3/1 (25.4.79)

247

-Legal and Institutional Implications

Accretion and erosion are both well-known concepts in national and
international law. Being natural processes, they do not per se give rise to
legal claims. However, interference with natural processes may well do so. At
a national level, actions will depend on the national legal system. In English
law, although the position is unclear, it can be argued that by analogy with
river siltation cases, action by one authority in building a barrage that
deprives another area of sediment could give rise to liability (see Paulden,
1986). However, again in English law, an action against a public authority
under public nuisance would normally be covered by the statutory defense.
13
Although in Tate and Lyle v. GLC and Port of London Authority (1983), the House
of Lords said, in finding the defendants liable in public nuisance for building
a ferry terminal that caused siltation of the plaintiff's jetty, that statutory
operations must in general be conducted "with all reasonable regard and care for
the interests of other persons."

The construction of bulkheads or sea embankments would have two major
effects on ecologically sensitive wetland areas, as discussed above. First, if
placed to prevent erosion of the upper shore, the bulkheads would restrict
sediment. movement across the shore profile so that the profile would fail to
adjust to the new water 1 evel . The resul tant prof i 1 e woul d therefore be steeper
than previously, and thus the ecologically important intertidal area would be
diminished. Such foreshore steepening is already noticeable along the shore of
eastern England (Anglian Water, 1988) and on the eastern seaboard of the United
States (Leatherman, 1987). Second, the active policy of preventing erosion of
cliff coastlines would deny the horizontal movement of sediments to the
adjoining depositional wetlands, such as salt marshes and mangroves -- areas
with extremely high ecological value.

It seems unlikely that states would seek or wish to denounce their
obligations under wildlife treaties -- e.g., the Ramsar, Bonn, and Berne
Conventions or other regional treaties. Their obligations to preserve habitat
are important legal constraints on available policy. In a case pending before
the European Court of Justice, the European Court Commission is impugning the
Federal Republic of Germany for building dikes in two zones (Leybucht and
Rysumer Nacken) that are considered as protected zones under the 1979 European
14
Economic Community Directive on Wild Birds. It is argued in this case that
only "exceptional circumstances superior to the law" which endanger human life
could justify work in these areas -- and even that would have to be strictly
necessary. It seems clear that at a subregional level, the European Court
Commission would be zealous to ensure that national strategies did not result
in the loss of important habitat, and in their current form would be likely to
maintain this position throughout the gradual changes that sea level rise would
entail.

13[ 1983] 2 AC 509

14 79/409/EEC, OJ L103/ (25.4.79)

248

Freestone and Pethick

The Passive Response

A passive response to sea level rise is one which would coincide with much
of the current thinking of many coastal geomorphologists -- namely, that
coastlines do find a natural equilibrium when left to themselves. There are,
however, several obstacles to implementing such an approach.

Artificial Embankments and Reclamation. First, a passive response would
be entirely acceptable were it not for the artificial embankment and reclamation
of large areas of the world's shorelines. In a completely natural system, it
seems likely that existing intertidal areas or coastal wetlands would keep pace
with sea level changes by continued accretion. In the case of artificially
protected reclaimed lands, this natural response is denied. The "passive"
response in this case would entail the abandonment of much low-lying coastal
land areas, either to inundation or to controlled inundation by a series of low-
lying banks. Areas so inundated would then keep pace with sea level rise by
natural accretion, always assuming that sufficient sediments are available from
elsewhere in the coastal system to satisfy the imposed sediment demand. In some
cases, this process may be accelerated by the introduction of sediment into the
coastal system. Thus beach nourishment processes, widely used at present, may
be supplemented with the artificial nourishment of intertidal mudflats and
marshlands. Such active intervention in natural processes may be seen as a mid-
way position between an active policy to prevent natural coastal response
completely and a totally passive response that allows natural conditions to act
unhindered.

Degleted Biological Activity. A second difficulty facing any passive
response policy may also be mentioned here. The most vulnerable areas of the
world's coastlines to sea level rise are the low-lying intertidal areas. These
areas accrete fine sediments largely due to the presence of biological
organisms, both animal and plant. Thus, coral reefs both reduce wave energy in
the lagoon areas beyond and at the same time act as a source of sand size
material necessary for the accretion of beaches and dunes in these lagoon areas.
In mudflat areas, the existence of algae on the surface accelerates the
accretion of fine-grained silts and clays, while in mangrove and salt marsh
areas the presence of a vegetation cover creates the necessary conditions for
the deposition of fine sediments. Consequently, the response of each of these
coastal types to sea level rise depends on the presence of one type of organism
or another. Yet in many cases, such biological activity has already been
removed or depleted by human activity, so that these coasts are not capable of
responding to the new conditions.

Coral reefs in the Caribbean and East Africa have been extensively damaged
by dynamite used illegally for fishing, and by pollution and coral mining.
Mangroves in many areas, such as in eastern Bangladesh (Stoddart and Pethick,
1984), have been totally deforested, and salt marsh vegetation has been reduced
by pollution and the extensive reclamation of such areas for agriculture,
industry, and housing. In these cases, the biologically impoverished coasts
will require active intervention before they are able to respond naturally to
sea level changes. The immediate suppression of coral reef damage, the planting

249

Legal and Institutional Implications

of mangrove species in tropical intertidal areas, and,J,4,e, protection of salt
marsh areas against further pollution and reclamationA@@:all ,.essential active
measures needed before a so-called passive policy may.,, e,-im'
plemented.

Loss of Major Coastal Habitat. Third, the ti.m.ing of a coastal response
under such a passive policy may causd severe difficuflti,b.@._ Thus, the response
of a coastline to rising sea level" may eventually,, be to Achieve sediment
I . j , , I
redeployment by removing material from one area and 'O"positin it in another.
9
But this interaction' may not be instantaneous. The,: I,oss of a major area of
coastal habitat without its immediate replacement,elsewhere can have economic,
social, and ecological repercussions..
A clear example of these repercussions is given@'in predictions for the
response to rising sea level, of the-n 'orth Norfolk coast of eastern England
(Pethick, 1989)'. This coast encompasses .%-s6eral nature reserves of
international importance, comprised of sand dune and,salt marsh. Each reserve
is separated from the other by int .ervening strettfie'@s of beach that attract
commercial recreationa'l activities. An examination of the wave refraction
pattern for the area demonstrates that this alteration of beach and marsh is
caused by the pattern of wave foci along the shore (Figure 3).

A wave focus i s created when a wave refraction pattern results in the
concentration of wave energy in one area of the coast. Such a concentration of
energy is compensated by the presence of a contiguous area of lower waves, and
this pattern of high- and low-energy zones is re'sponsiblefor the beaches and
marshes of the north Norfolk coast. Figure 3 demonstrates that, under a rising
sea level, these wave foci will swing eastward along the coast, so that
eventually the marsh areas of the National Nature Reserves will be replaced by
high-energy beach deposits, and the thriving holiday-,beaches-of today will in
turn be replaced by mudflat and marshland. Thus, the'tommercial and ecological
coastal zones here will be interchanged, but the response will be gradual, with
the beach areas gradually silting over and the nature reserves gradually being
eroded away.

While this is happening the response of both humans and wildlife to the
gradual loss of their chosen habitat-'depends entirely on the rate at which the
changes occur and the rate at which' they are able to modify their present
behavioral patterns. One outcome could well be the failure of both coastal
users to synchronize with the changes imposed by'the coast, and the loss of both
ecological and commercial activities on this co-astli'ne.

As well as these practical difficulties facing any passive approach policy,
there are many economic and legal issues involved. Thus, a purely passive
approach carried out in a developed zone where large areas of reclaimed
marshland are present must involve the abandonment of these areas to the rising
sea. Such an approach might reflect a cost-benefit analysis of the advantages
of the value of low-lying arable lands against the open-ended cost of defending
them. New natural wetland areas would) be created to.-treplace those inundated
ones. However, the problems with this approach-,areat-least twofold:

250

Freestone and Pethick

A PRESENT
SEA LEVEL
North Easterly wave.
8 sec period

wave refraction under
present sea level
ADMIRALTY CHART
BATHYMETRY
il::11 below Sm
5 - 10 ITT

10W
it U'- I 3141kv.ey
rHE
NATION 14ATURE
RESERVE NATIONAL NATURE
WASH RESERVE
RICREMIONAL RECREATIONAL
KACH COAST BEACH COAST

B SEA LEVEL oe
RISE
North Easterly wave,
8 sec period

Wave refraction assuming
a +3m rise in sea level

;ij
cc I
rHE 4
NATIONAL NATURE
WASH M400606. RIESHAN E NATIONAL NATURE
RESERVE
*I!CQ ATIONAL RUAGATIONAL
BEACN COAST BEACM COAST

0 20
I
km

Figure 3. Changes in wave fod'oft the north Norfolk coast due to sea level
rise, showing implications for nature reserves and recreational areas.
461

Legal and Institutional Implications

1. It would be impossible to pursue such a policy without exceptions.
In any cost-benefit analysis, low-lying cities would have to be
defended. It would be politically impossible to abandon London or the
whole of the Netherlands.

2. It requires cooperation to be successful. It requires both
intranational (e.g., Federal Republic of Germany/The Netherlands) and
international (e.g., United Kingdom/The Netherlands) cooperation. In
order for a coastline to find its natural equilibrium, maximum
sediment mobility is necessary. The necessary legal machinery to
enable cooperation among states to ensure such mobility must be
developed.

So, although this might be a passive policy in some respects, it is not a
politically passive option. It would require considerable cooperation at both
local and regional levels. The final question to be addressed, then, is whether
international law imposes an obligation to cooperate in such a way.

DOES INTERNATIONAL LAW REQUIRE COOPERATION?

Under classical international law, a state had complete and unchallengeable
jurisdiction within its own territory. However, it is now recognized that
states must respect the rights of their neighbors -- for example, by behaving
equitably in relation to shared resources (e.g., the Diversion of Water from the
Meuse case") and by not permitting the escape of pollution that would damage its
neighbor's territory (Trail Smelter Arbitration"). The principles of the 1972
Stockholm Conference 17 declare that:

States have in accordance with the Charter of the United Nations and
the principles of international law, the sovereign right to exploit
their own resources pursuant to their own environmental policies, and
the responsibility to ensure that activities within their jurisdiction
or control do not cause damage to the environment of other states or
of the area beyond the limits of national Jurisdiction [italics
added].

In the light of a modern view of the interdependence of ecosystems and,
indeed, of the world ecosystem, it seems widely agreed that international law
does not permit actions that damage other states or "common areas." An example

"(1937) Netherlands v Belgium, PCIJ Reps, series A/B, No 70
16(1938/41), U.S. v Canada, 3 RIAA 1905

"'Report of the UN Conf on the Human Environment. UN Doc A/CONF, 48/14; 11
ILM 1416 1972. Principle 21

252

Freestone and Pethick

of this is the Hnternational Law Commission's proposal" that massive marine
pollution should be an "international crime" (Smith, 1988).

Any attempt to relate these developments to the novel problems posed by
national responses to sea level rise must address the problem that the nature
and potential scale of the issue has no direct precedent. It seems clear that
the full implications of the effects of sea level rise have not yet been fully
appreciated. International lawyers are only just beginning to address the
problems that this rise poses. This does not mean that there is an
international law vacuum, but simply that the applicable principles are in the
process of adaption and crystallization. Al 1 that can be done here i s to
suggest a number of approaches to analogous problems, which may shed some light
on possible approaches.

Unfortunately, there are no direct analogies. National laws may suggest
a number of principles -- albeit different -- to the problem of state responses
that exacerbate erosion and land loss in neighboring states. However, the
closest analogy of cross-boundary environmental damage appears to be with the
problems of pollution where the behavior of one state affects the interests of
others. Actions for damages have tended to be restricted to cases of direct
damage; the position is less clear with indirect damage.

Rather than considering liability for breach of obligations, however, it
may be more positive to consider whether international law prohibits certain
courses of action, or can require cooperation. Of considerable importance in
this connection is the emergence in international environmental law of the
Precautionary Principle, or the principle of precautionary action. This
principle is derived from national environmental law. Gundling (in press)
describes the principle as:

... a more stringent form of preventative environmental policy. It is
more than the repair of damage or the prevention of risks.
Precautionary action requires reduction and prevention of
environmental impacts irrespective of [proven] risks.

The principle is accepted by the North Sea states in relation to marine
pollution, and is included in the 1987 London Declaration on the Protection of
the North Sea."' This year it was also accepted by the parties to the 1974 Paris

"For text see YB ILC, 1979, part II, page 90 and 1980, Part II, page 14,70.
Article 19(3)(d) refers to "a serious breach of an international obligation of
essential importance for the safeguarding and preservation of the human
environment such as those prohibiting massive pollution of the atmosphere or of
the seas."

"Second International Conference on the Protection of the North Sea,
Ministerial Declaration, Nov 1987. Reproduced (1988) 3 International Journal
of Estuarine and Coastal Law, pp. 252-265.

253

Legal and Institutional Implications

20
Convention on pollution from land-based sources. While Gundling does not feel
that it has yet emerged as a general norm of international law, he identifies
its use in a number of important environmental documents, including the Ozone
Layer Convention (1985 Vienna Convention 2' and 1987 Montreal Protocol 12) , as well
as the 1972 Stockholm Declaration itsel f2l , the 1982 UNEP Nairobi Declaration 24
(stressing the necessity of environmental management and EIA as well as proper
plannin? of all activities), and the 1982 UN General Assembly "World Charter of
Nature" 5 (in which the principle is urged in relation inter alia to protection
of habitat and planning).

While these are not strict treaty obligations applicable to the current
problem, states that participated in creating these agreements must find it
difficult to deny the validity of the principles. they set out.

In addition, Principle 21 of the 1972 Stockholm Declaration on the Human
Environment (adopted by acclamation of 113 participating states) declared that:

States have... the responsibility to ensure that activities within
their jurisdiction or control do not cause damage to the environment
of other states ...

It does seem that, faced with a problem -- such as sea level rise -- in
which a high degree of coordination and cooperation may be required to prevent
unilateral actions exacerbating neighbors' erosion problems, that at' the very
least states would stop arguing that this is a matter entirely within their own
jurisdiction.

There are precedents in international law for obligations to cooperate or
to negotiate in good faith. For example, in the field of natural resources law,
and more particularly the emerging rules on exploitation of joint liquid and gas
deposits, it is now argued that not only is "unconsented" exploitation of a
joint liquid mineral deposit (in such a way as to damage the neighbor's right
to exploit that deposit) illegal, but also that, as Lagoni (1979) argues, state
practice:

20 Paris Commission (PARCOM) Recommendation 89/1 22 June 1989

`1985 Vienna Convention on the Protection of the Ozone Layer.

221 987 Montreal Protocol to the Vienna Convention above.

23 See above note 17, Principles 2, 3, and 5.

24 Nairobi Declaration on the State of the World Wide Environment. 18 May
1982, 21 ILM 676 (1982).

251 982 UN General Assembly Resolution on the World Charter for Nature, UN
Doc A/RES/37/7, 9 Nov 1982, 22 ILM 455.

254

Freestone and Pethick

has given rise to a customary rule of current international law. That
rule means that ... no state may exploit a common deposit of liquid
minerals before having negotiated the matter with the neighboring
state or states concerned.

Of course, this rule cannot be translated directly into environmental law.
But it does demonstrate that cooperation can develop even in areas that have
been traditionally regarded as close to states' vital interests -- hydrocarbon
resources.

It is unclear whether there is an obligation for states under customary
international law -- independent of treaty -- to cooperate in planning their
responses to sea level rise. Nevertheless, this paper has sought to demonstrate
that such an obligation is a necessary part of a measured and planned response.
If the obligation to cooperate does not emerge through customary international
law, it should be enshrined in treaty.

BIBLIOGRAPHY

Aurrecoechea I., and J.S. Pethick. 1986. The coastline: its physical and
legal definition. International Journal of Estuarine and Coastal Law 1:29-42.

Anglian Water. 1988. The sea defense management study for the Anglian Region.
Internal report. Sir William Halcrow & Partners.

Blake G., ed. 1987. Maritime Boundaries and Ocean Resources. London: Croom
Helm.

Bruun P. 1962. Sea level rise as a cause of shore erosion. J. Waterways and
Harbors Div. ASCE 88:117-130.

Dean, R.G. 1987. Coas tal sediment processes: toward engineering solutions.
In: Coastal Sediments 87. K. Kraus, ed. New York: American Society of Civil
Engineers, 1. p. 1-24.

Freestone, D. 1989. Maritime boundary delimitation in the eastern Caribbean.
Proceedings of the 1989 International Boundary Research Unit. Conf. Durham UK

Gundling L. (In Press). The status in international law of the principle of
precautionary action. In: The North Sea: Perspectives on Regional
Environmental Cooperation. D. Freestone and T. Ijlstra, eds. Martinus Nijhoff.

Komar, P. 1976. Beach Processes and Sedimentation. Englewood Cliffs, NJ:
Prentice Hall.
Lagoni, R. 1979. Oil and gas deposits across national frontiers. Amer. J.
Int. Law 73:215-243.

Leatherman, S. 1987. Beach and shoreface response to sea-level rise: Ocean
City Maryland, USA. Progress in Oceanography 18:139-149.

255

Legal and Institutional Implications

Lyster, S. 1985. International Wildlife Law. Grotius.

McCave, I.N. 1987. Fine sediment sources and sinks around the East Anglian
Coast (UK). J. Geol. Soc. Lond. 144:149-152.

Nummedal, D., and S. Penland. 1981. Sediment dispersal in Nordermeyor Segat,
W. Germany. Spec. Publ 5. Liege, Belgium: International. Association of
Sedimentologists, pp. 187@200.

Paulden, P. 1986. Ferry terminals as a public nuisance. International Journal
of Estuarine and Coastal Law 1:70-74.

Pethick, J. 1989. Waves of change: coastal response to sea level rise. Geog.
Analysis 19:1-4.

Pethick, J. 1989. Scolt Head Island and changes in wave refraction. In: The
Effects of Sea Level on Sites of Conservation Value in Britain and North West
Europe. T. Hollis, D. Thomas, and S. Heard, eds. World Wide Fund for Nature.

Prescott, J.R.V. 1985. Maritime Political Boundaries of the World. Methuen.

Prescott, J.R.V. 1989. The influence of rising sea levels on baselines from
which national claims are measured. Proceedings of the 1989 International
Boundary Research Unit Conf. Durham UK.

RAMSAR. 1987. Directory of Wetlands of International Importance. IUCN

Sand, P.H. 1989. Marine Environmental Law in the United Nations Environmental
Programme. Tycooly.

Smith, B.D. 1988. State Responsibility and the Marine Environment. Oxford.

Stoddart, D.R. and J.S. Pethick. 1984. Environmental hazard and coastal
reclamation: problems and prospects in Bangladesh. In: Understanding the
Green Revolution. T. Bayliss-Smith and E. Wanmali, eds. Cambridge: Cambridge
University Press.

256

LEGAL IMPLICATIONS OF SEA LEVEL RISE IN MEXICO

DIANA LUCERO PONCE NAVA
International Law Coordinator
Legal Adviser's Office
Mexican Foreign Ministry
Mexico City, Mexico

ABSTRACT

In the search for adaptive options to sea level rise and other impacts of
global warming, this paper analyzes the basis for environmental protection in
the Mexican legal system and briefly looks at some aspects of international law.

EVOLUTION OF MEXICAN ENVIRONMENTAL LAW

The evolution of environmental law in Mexico has followed the same course
as international law. The first 60 years of this century saw an effort by
developing countries to assert sovereignty over their natural resources. It
was not until 1962 that the United Nations General Assembly adopted resolution
1803, which recognized "permanent sovereignty over natural resources." Although
there were other resolutions, it was not until 1972 at the Stockholm Conference
on Human Environment, that Principle 21 associated the concept of sovereignty
over natural resources with the goal of conservation of the environment for the
sake of future generations. Before then, environmental laws were more concerned
with the "cleaning" and "reparation" of already polluted areas. Since then, the
approach has been to relate the environment to the national welfare and
development by providing rules for the exploration, exploitation, administration,
and conservation of Mexico's natural resources.

Article 27 of the Federal Constitution of Mexico has been amended 24 times
since the Constitution's enactment in 1917. This considerable number of
amendments reflects the evolution of the growing control of the Mexican State
over its natural resources. The current Article 27 establishes the property
regi-me that determines the specific economic and social system of Mexico. It
states that the Mexican territory belongs to the nation, and it establishes
direct and eminent domain over all natural resources. Although the Constitution
recognizes private property, it allows for the imposition of any conditions on
such property required by the public interest.

257

Legal and Institutional Implications

ECONOMIC ACTIVITIES

The approximately 5,000 kilometers of Mexican coastline are not considered
a unitary natural resource. For this reason, there is no single authority to
manage them. Rather, they are managed on the basis of their different economic
activities.

The federal Constitution of Mexico establishes the areas and activities
that are subject to federal legislation. Any activity not expressly set within
the federal rules is understood to be under the control of the local rules of
states and municipalities.

Mining and Exploitation of Fossil Fuels

The mining and exploitation of fossil fuels in Mexico are highly developed
and account for one-tenth of the GNP. Oil and natural gas reserves, as well as
salt mines, are located in coastal areas. As mentioned above, the federal
Constitution has established that the state has direct domain over -these
resources. Generally, concessions may be made to nationals and foreigners for
exploitation of mines, but not for exploitation of fossil fuels. The petroleum
industry is managed by PEMEX, the largest enterprise in Latin America. In
compliance with environmental laws, PEMEX has undertaken some preventive and some
corrective programs, but none that address the problem of global warming or sea
level rise.

Fishing

Fishing is another important federally regulated industry. Fishing
cooperatives dominate in the coastal area, especially on the west coast. Well-
developed laws exist for the protection of the marine environment, but the impact
of potential sea level rise caused by global warming is not currently addressed.

Ports and Harbors

During 1985, Mexican ports handled 2,206,643 deadweight tons of commercial
goods. The Mexican Ministry for Communications and Transport spends a great
amount of its budget on the construction and maintenance of ports, but there are
no laws or programs providing for the prevention of damages from sea level rise.

Tourism

Tourism is another profitable industry along the coast. Mexican beaches
are recognized worldwide and bring approximately $2 billion (U.S. dollars)
annually into the country. In principle, tourism is a matter for local
regulations. However, the tourist industry involves a great deal of fore@ign
investment, which is subject to federal rules.

Two aspects of foreign investment in tourist facilities are of particular
interest. One is that local developers built tourist facilities 500 meters to
one kilometer away from the beach. It was foreign investment that brought the

258

Ponce Nava

concept of huge beachfront facilities to Mexico. Another interesting aspect is
that the federal constitution prohibits foreign ownership of land for a 50-
kilometer-wide belt along the coastline. Because of this, a legal device was
created for foreign investment in the form of a trust. The trustee is always
a national bank that holds possession of the land, and the foreign investor
becomes a beneficiary for a period of 30 or more years.

Mexican law provides for state ownership and federal control of land
reclaimed from the sea. Loss of land, however, is considered a natural
phenomenon and the owner of such land would bear the cost of a loss, with no
right to compensation.

Forestry and Agriculture

Forestry is managed under federal rules, while agriculture and cattle
ranching are a matter for local legislation. Environmental laws at both the
federal and local levels establish extensive control of the exploitation,
conservation, and administration of those resources. Once again, it was not
possible to find specific rules to address the potential problem of sea level
rise.

Socioeconomic Obstacles to Planning for Sea Level Rise

Relying on the existing legal framework, it would be possible to begin
addressing a globally planned response to climate change and sea level rise.
But before proposing adaptive options, it is necessary to see how this legal
framework relates to the socioeconomic conditions in the coastal areas of Mexico.

There are many conflicts between the development interests and the local
economics based on coastal resources. Many of Mexico's coastal communities have
marginal economies. In these communities, everyday activities are a matter of
survival. Authorities at both the federal and the local levels are attempting
to satisfy the basic needs of these communities, rather than thinking about
responses to a problem not yet scientifically proven.

Although the Mexican people want to raise their standard of living, we need
to ask what kind of development should be allowed. Industrialization and growth
on the basis of existing technology will contribute to the problem of global
warming.

ADAPTIVE OPTIONS

A great deal of work has been done, but much more work is needed to find
a balance between sustainable development and conservation of natural resources
and protection of the environment.

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Lega7 and InstitutionO Imp7ications

At the National Level

To deal with a potential sea level rise, we will have to think of the
coastal zone as a unitary natural resource, and then provide for its management
either by existing authorities or by a newly created authority. (In relation
to hydrological resources, while groundwaters are susceptible to appropriation
by individuals, underground water is controlled by the state. In both cases,
there are no laws or programs to address the potential impacts from global
warming or sea level rise.)

The Mexican government needs to make use of environmental regulations
already in force to prevent or to adapt to global warming. It must also
disseminate sound scientific information about the causes and risks of global
warming among authorities both at the federal and local levels.

At the International Level

A global response of the international community is required to face the
cl imate change. International cooperation is needed, with due respect to
national needs and priorities. Now that the principle of permanent sovereignty
over natural resources has been achieved, the IPCC process should be used to make
governments and people aware of the real value of natural resources.

260

LEGAL AND INSTITUTIONAL IMPLICATIONS OF ADAPTIVE OPTIONS
OF SEA LEVEL RISE IN ARGENTINA,'URUGUAY, AND SPAIN

DR. GUILLERMO J. CANO
Executive Director
Fundacion Ambiente y Recursos Naturales
Buenos Aires, Argentina

ABSTRACT

This paper covers the following subjects concerning the legal regimes of
Argentina, Uruguay, and Spain, countries riparian to the Atlantic Ocean and
having a system of written statutory law originating in the Roman law tradition:
factors common to the countries surveyed; two basic legal principles, periculum
and commodum, which are allocated by Nature (acts of God); men are responsible
for damages produced by sea level rise when this does not happen as an act of
God; complexity of the legal and administrative regimes of maritime coastal
areas; boundary delimitation of the public and private domain in maritime coastal
areas; other lines and strips linked to the legal maritime high-water mark;
maritime-coastal wetlands; and legal rules as tools to promote or discourage
human influences in changing the high-water mark, and government powers based
on them.

INTRODUCTION

The legal systems of Spain, Uruguay, and Argentina are not based on common
law. Rather, they are derived from ancient Roman law following a regime of
written statutory law. Argentina is a federation, institutionally quite similar
to the United States.

This study looks at the legal powers of these three countries with regard
to adopting suitable measures to adapt to the difficulties that could arise from
the predicted sea level rise. These adaptations may not necessarily include the
preservation of wetlands.

TWO BASIC LEGAL PRINCIPLES: "PERICULUN" AND "COMMODUM"

The judicial wisdom of the ancient Romans led them to state the legal
principle that it is nature that distributes the periculum (danger, damages) and

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Legal and Institutional Implications

the commodum (comfort, benefits). We relate "nature" to the agnostics and "acts
of God" to the believers. Legally, both expressions have the same meaning.

Since ancient Rome, this principle has governed the relationships among
states and individuals and has been translated into a number of rules of the
civil codes. For instance, the owner of a piece of land has the right to receive
the waters descending onto his land from above it, provided the waters descend
as a result of nature and not the work of humans. When the waters are produced
directly or indirectly by human influence, the responsibility for any damage lies
with the people who have initiated the activity. Argentina's Court Supreme
admitted the applicability of this principle in a sentence dictated in 1986
(Fallos 175:133).

The principle has economic implications. If a man chooses to live on a
flood-prone riverside, he accepts the risk of being flooded and of bearing the
consequences of the periculum, provided the flood is not produced by the work
of another human being. If a flood is caused by human activity, the people
responsible for the activity are also responsible for the damages the man
suffers. But, in this example, the man who chooses to live there also takes
into account the commodum, as he benefits from having at his disposal cheaper
water to fulfill his needs, perhaps combined with panoramic beauty and a lower
price for the land.

In the field of international law, it is a generally accepted principle
that no country can produce in a river basin damages that could significantly
affect another state of the same basin (Cano, 1979b).

LEGAL AND ADMINISTRATIVE COMPLEXITIES

In the maritime coasts of Uruguay, Argentina, and Spain, there is a mixture
of salty seawaters. The regular tides are mainly due to lunar attraction; in
fresh waters of continental origin (superficial and subterranean), the tides
depend on either rain or snow. Generally, the two kinds of waters are subjected
to different legal regimes and are under different administrative organizations.
As far back as 1975, several people favored consolidation of the maritime and
continental water laws (Cano, 1975; Sewell, 1976).

In addition, the soil along the coasts generally belongs to different
people. The beaches and the immediate sea bed are often in the public domain,
and the adjacent lands inland are often private property. Thus, they are subject
to different legal regimes. In federal countries, like the United States and
Argentina, the situation is more complex, since the public domain is sometimes
federal and other times local, or the jurisdiction is federal for certain uses
of the water (navigation) and local for other uses (irrigation, domestic
consumption, etc.). Complicating things even further, other natural resources
along the coast are interrelated with the land and the water (flora and fauna,
minerals) and are also subject to different laws and authorities (Sneader and
Getter, 1985).

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Cano

Many coastal cities, towns, and ports are administered by another
governmental level: the municipalities or town councils. This makes matters
worse, especially if there is a sea level rise that floods urban areas
permanently. This would displace thousands of people, causing not only legal
problems but also social problems. Christina Massei has written about this
subject for this meeting (see Massei, Central and South America, Volume 2).

DELIMITING PUBLIC AND PRIVATE DOMAIN

In the maritime coasts of Uruguay, Argentina, and Spain, the beach, the sea
bed, and the waters seaward of the maritime high-water mark belong in the public
domain. Inland, the land is private property. While the high-water mark or high
tide is used to divide the public from the private domain, the low-water mark
is used in politico-international relations, as it serves as a starting point
to measure the beginning of the territorial sea, or the exclusive economic zone.

That low-tide mark, or low tide, can be physically delimited on the beaches
or the cliffs. It is called the normal base mark or reduction plan. Sometimes,
however, a riparian government chooses to draw straight lines between the capes
that mark either gulfs or bays and to state that all that remains inland in those
marks is -- in relationship with other nations -- of its exclusive domain and
sovereignty. These marks are called "base straight marks" (Cano et al., 1989).
Due to a Joint Declaration made on January 30, 1961 (ratified by the Montevideo
Treaty on January 19, 1963), both Argentina and Uruguay defined -_ in
relationship with third nations -- the frontal border of the Rio de la Plata,
which they share. The territorial sea of both countries starts seaward from that
straight base mark (which is 230 km long) (Cano, 1979b).

In the Republic of Uruguay, along the coasts of the Rio de la Plata and on
the Atlantic Ocean, the high-water mark is determined by the average of maximum
annual heights over a 20-year period (Gelsi Bidart, 1981). In Spain, according
to its 1985 Water Law, the high-water mark is determined similarly, but is
averaged over 10 consecutive years (Gonzalez Perez et al., 1987).

Concerning the river coasts, the civil codes of the three countries we are
dealing with provide that if sediments accumulate naturally, the extended surface
that forms (called "alluvium") increases the property of the riparian landowners.
But if the riverside consists of a road, wall, or another public work, the
alluvium becomes public property. This is one example of enforcement of the
principle that nature distributes the periculum and the commodum. But the laws
of those countries do not offer the same solution for the maritime coasts,
because physical aggregate by alluvium cannot be produced in them. On the other
hand, it could occur the other way around: erosion by the sea could forever
diminish the property of the riparian landowner. It is worth adding that within
the public domain (beaches, etc.), individuals cannot build -- or even plant
-- anything without a license from the government.

If the maritime high-water mark rose permanently, for example, because of
a sea level rise, it would be necessary to redraw the mark, and the riparian or
littoral owner would lose the property of the flooded lands. Such a solution

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Legal and Institutional Implications

has been proposed for a future reform in the Argentine legislation (Cano et al.,
1989).

In the Argentine federation, the maritime beaches, the sea bed, and the
waters up to three miles seaward are the property of and under the jurisdiction
of the government of the littoral province. Navigation is under federal
jurisdiction, even though the soil, the water, and the jurisdiction over all the
nlon-navigational uses (fishing, mining, etc.) of the water and the bed still
belong to the provincial government (Cano, 1979a). The safety of navigation
is.also under the jurisdiction of the federal government, through the Prefectura
Naval Argentina (equivalent to the U.S. Coast Guard Service). According to the
Constitution, the ports can be regulated only by the federal government. Thus,
the harbor patrol, even for non-navigational purposes, is exclusively exercised
by the Prefectura Naval.

On the maritime Argentine coast there can be more than one legal high-water
mark. One is established by the federal government only for the sake of its
jurisdiction over navigation; the other one is adopted by the governments of the
littoral provinces for all the other purposes. In fact, the government of Buenos
Aires Province (Cano et al., 1989) has created a 150-m-wide strip inland of the
legal high-water mark, where construction of buildings is prohibited.

In general, this strip is occupied by dunes. If the dunes extend beyond
100 m, the prohibition strip becomes larger to accommodate the full extension
of the dunes.

In Argentina, for the purpose of navigation, the legal high-water mark is
physically established in terrain by the National Directorate for Port Works and
Navigable Waterways. Also in Argentina, along the maritime coast, the legal low-
water mark or reduction plan is physically delimited by the Navy's Hydrographic
Service, which is also in charge of delimiting the straight base marks.

OTHER LINES AND LAND STRIPS LINKED TO THE LEGAL MARITIME HIGH-WATER MARK

Starting from the legal maritime high-water mark and moving landward, in
Argentina there is a strip 50 m wide, all along the maritime coast. The
Prefectura Naval (federal agency) exercises its navigational jurisdiction over
this strip. Inland of that strip, the soil is the property of the riparian
landowner, without restrictions on its use.

Second to the federal civil code, along the bands of navigable rivers in
Argentina, there is a 35-m-wide legal servitude, or right-of-way. This is called
"towrope servitude," or riverside way. The riparian landowners must keep that
strip free to enable transit, and they cannot build on it or plant any trees
(Cano et al., 1989).

In the Rio de la Plata (one riverside of which is Argentine and the other
Uruguayan), a special situation occurs. The high-water mark is determined both
by the tides and by the flow of the Parana and Uruguay Rivers, the union of which
forms the Rio de la Plata (that on the whole amounts to a flow of about 11,000

264

Cano

M'/sec). When strong winds from the southeast prevail in the mouth of the Rio
de la Plata, which is 220 km wide, they block the normal flow of the river
waters, and the riparian lands become flooded. In Argentina as well as in
Uruguay, the Rio de la Plata is legally considered a river and not an estuary.
Thus, the strip of 35 m devoted to protect navigation is applicable (Gelsi
Bidart, 1981; Cano et al., 1989).

Recently proposed reforms to the Argentine legislation would (1) create in
the maritime coast a "service zone" 10 m wide, which the landowner must keep
free for transit (such a zone does not exist at present); (2) forbid landowners
next to the legal maritime high-water mark from carrying out excavations that
could alter the mark's altitude; (3) grant the landowners next to the legal
maritime high-water mark the right to request from the government the physical
delimitation of the marks, in procedures that must be carried out with the
government's participation (the procedures must be carried out again if the mark
naturally changes through an act of God); (4) maintain in that maritime coast
the strip of 50 m so that the navigational safety police can carry out their
responsibilities; (5) create a servitude of floodways along the 350 km of
Argentine coast of the Rio de la Plata, which would eventually be subjected to
sea level rise (the land use would be subjected to restrictions imposed by the
provincial government, which would apply throughout the width of the floodway
up to the 25-year floodplain); and (6) create along the banks of the Rio de la
Plata another strip called the "flood-prone area," which strip would be
determined by the level that flood waters are expected to reach every 100 years
(this strip would also be subjected to use restrictions, but they would be less
severe than those imposed by the provincial government) (Cano et al., 1989).

According to article 2611 of the Argentine Civil Code, the restrictions to
the public property are imposed for the public interest (and not for the interest
of any individual person). These restrictions are established by the
administrative law, and the power to carry them out belongs to the provincial
governments.

On the Atlantic coast are four provinces (Buenos Aires, Rio Negro, Chubut,
Santa Cruz) and two federal territories (city of Buenos Aires and Tierra del
Fuego). In the two territories, the federal government acts as a local authority
where such local powers can be exercised. Restrictions can be imposed on private
property without compensating the owners, but when the restrictions call for
establishing servitudes (rights-of-way), the owners must be compensated. Even
more, when landowners are deprived of their property because of eminent domain,
the Constitution requires full compensation. The mere "restrictions" only imply
abstentions that the owner must tolerate. They apply to everyone in the same
situation and are for the general benefit of the public, rather than of an
individual (Cano et al., 1989).

Uruguay has an identical legal regime for the legal high-water mark for its
maritime coasts and for those of Rio de la Plata. Its strip of defense along
these areas is 250 m wide. Along the strip, the domain of landowners is
restricted (landowners may not remove sand), and the government can impose more
restrictions as it deems necessary (Cano et al., 1989). Uruguay has a different

265

Legal and Institutional Implications

regime for its other fluvial coasts (the Uruguay, Cuareim, and Yaguaron Rivers,
the last two bordering with Brazil) (Gelsi Bidart, 1981).

Maritime Law

Spai n speci f i es two stri ps (Gonzal ez Perez et al . , 1987; Cano et al . , 1989):

� a zone of servitude 5 m wide, for public use, fishing, and rescue/life-
saving; and

� a police zone of 100 m, where a governmental license is required to alter
the natural relief of the terrain, to remove stones or sand, to construct
buildings, or to initiate any other activity that could obstruct the free
flow of flooding waters.

A SPECIAL CASE: MARITIME COASTAL WETLANDS'

In Argentina, the wetlands are not administered by the federal government.
Some provincial laws (but none of them from provinces with maritime shores)
govern them, but those laws allow and even require their drying up so that the
provinces can recover their beds for farming and can put the waters to other
uses. If the coastal wetlands are below the legal maritime high-water mark,
they are part of the public domain and are subject to its regime.

Argentina is not a signatory of the Ramsar Convention. The federal
legislation recently planned by the.author of this document (Cano et al., 1989)
proposes to adopt a definition of wetlands that differs from the Ramsar
Convention's definition and that is very similar to the definition of the U.S.
Corps of Engineers and of the U.S. Fish and Wildlife Service. The proposed
definition would limit the depth to one meter and would demand the presence of
anaerobic vegetation. The explicit proposal is to declare wetlands as being in
the public domain, as would be the case with coastal wetlands when they surpass
the legal maritime high-water mark. How the wetlands would be used would be
subject to what each provincial government decided for its territory.

When the Uruguayan government ratified the Ramsar Convention, a conflict
arose over the conceptual disagreement between the Convention and the preexisting
Uruguayan legislation (the 1979 Water Code and the 1875/1943 Rural Code). This
former legislation protects the wetlands when they have autochthonic fauna,
whereas the Ramsar Convention refers to migratory birds (waterfowl) (Laciar,
1989). Although the Rocha Swamplands were protected by preexisting rules
(article 161 of the Water Code), the Convention authorized their drying up. In
1987, a group of ecologists obtained a judicial verdict that paralyzed the
drainage works.

This study examines only the maritime coastal wetlands and not
Mediterranean wetlands.

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Cano

In Spain, wetlands are ruled by the Ramsar Convention, the 1985 Water Law,
and the Coasts Law. For example, the Coasts Law rules over coastal wetlands
(Laciar, 1989), especially over how to delimit them. The administration of
wetlands is shared by the Water and the Environmental Authorities (Martin Mateo,
1981; Cano et al., 1989). Their legal regime includes the artificially created
wetlands, and the margins of any wetland could also be added.

All activity in the wetlands is subjected to licenses or concessions. If
the Water Authority decided to encourage their drainage, it would have to consult
the Environmental Authority. In the wetlands, the water is within the public
domain, but the beds and the other natural resources can be private property
(Cano et al., 1989). Wetlands that are declared to be of special ecological
interest are subjected to concessions of more severe conditions.

RULES GOVERNING THE HIGH-WATER MARK

We have seen that, in general, the countries under study can
administratively impose restrictions on the use of private lands adjacent to the
sea without compensating the owners when the restrictions are of a general
character, when they relate to the public interest (as determined by the
parliaments of these countries), and when they do not imply a substantial limit
on the private property. Moreover, if they compensate landowners, these
countries can also impose rights-of-way and even forcibly buy the necessary lands
based on the public interest.

With regard to programs for mitigating flood damages (Cano et al., 1989),
Canadian and U.S. practices have strongly influenced the kind of restrictions
these countries are imposing on people who choose to live in flood-prone areas.
The program includes mandatory insurance, the cost of which is shared by the
population of other areas, through a public subsidy for the insurance. This
could be an example valid for the coastal zones subject to sea level rise.
However, I only suggest this as a mere possibility that should be open to a more
careful study and discussion.

The discussion has already begun on the subject of the responsibilities of
governments and individuals due to the global warming.

As the projected the sea level rise has not yet occurred, it is still
possible to take preventive measures; this course would be cheaper because it
does not try to correct existing situations. It is possible to restrict the
present and future uses of coastal properties by introducing long-term planning
and land use zoning. Taxation and other restrictions could also be used to
discourage settlement in and use of the coastal zones, or to create funds to
support the changes.

The question of the diversity of political and administrative jurisdictions
in the coastal zones, especially in the cities, deserves special consideration.
Horacio Godoy (1981) proposed for Colombia the creation of a Maritime Authority,
to address the coastal problems. That form of inter-administrative coordination
must be explored to confront the problem we now must fact.

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Legal and Institutional Implications

BIBLIOGRAPHY

Gelsi Bidart, A.G. 1981. Codigo de aguas de la Republica Oriental del Uruguay.
A. Fernandez, ed. Montevideo.
Cano, G.J." 1975. Evolucion historica y geografica del derecho de aguas y su
papel en el manejo y desarrollo de los recursos hidricos. Valencia:
International Association for Water Law.

Cano, G.J. 1979a. Derecho, politica y administracion mineros. Buenos Aires:
Fedye, p. 229.

Cano, G.J. 1979b. Recursos Hidricos Internacionales en la Argentina. Buenos
Aires: V. de Zavalia.

Cano, G.J., et al. 1989. Estudio sobre linea de ribera. Buenos Aires: CFI,
Consejo Federal de Inversiones, Volume 1.

Convention on Wetlands of Internation Interest, Especially as Waterfowl Habitat.
Ramsar, February 2, 1971. In: International Environmental Law - Multilateral
Treaties, R. Muecke and E. Schmidt, eds. Paris: Verlag, p. 971:09, and Protocol
signed in Paris on December 3, 1982. Published in Spanish in "Ambiente y
Recursos Naturales - Revista de Derecho, Pol itica y Administration" Vol. 111-2,
p. 107 (June 1986, edited by Fundacion Ambiente y Recursos Naturales. Buenos
Aires, Argentina).

Godoy, H.H. 1981. Administracion del mar - Informe de la mision a Colombia,
April 1979. UN/DTCD.

Laciar, M.E. 1989. Regimen Legal de los Humedales Costeros en la Argentina,
Uruguay y Espana. Buenos Aires: Informe de la Fundacion ARN para el
Environmental Law Institute.

Massei, C. Sea Level Rise: The living strategies concept in the context of
Latin American relocation policies (including wetlands). Buenos Aires:
Fundacion Ambiente y Recursos Naturales.

Mateo, R.M. 1981. La proteccion de las zonas humedas en el ordenamiento
espanol. Refista de Administracion Publica 96:8.

Perez, J.G., J.T. Jaudenes, and C.A. Alvarez. 1987. Comentarios a la ley de
aguas. Madrid: Editorial Civitas..

Sewell, W.D. 1976. Planning challenges in the management of coastal zone water
resources. A.J.A. II (Caracas) 2:567.

Sneader, S., Getter, C.H. 1985. Costas - Pautas para el Manejo de los Recursos
Costeros. Publication No. 2. Columbia, SC: U.S. National Park Service/AID.

268

PRESERVING COASTAL WETLANDS
AS SEA LEVEL RISES: LEGAL OPPORTUNITIES
AND CONSTRAINTS

ROBERT L. FISCHMAN AND LISA ST. AMAND
Environmental Law Institute
1616 P Street, N.W.
Washington, D.C. 20036

INTRODUCTION

Many scientists are predicting an increase in the Earth's surface
temperature as a result of "greenhouse gases" being introduced into the
atmosphere. A temperature increase may lead to higher sea levels, inundating
coastal wetlands. Under natural conditions, coastal marsh grasses could retreat
landward of the inundated wetlands and maintain a constant vegetated edge between
dryland and open coastal waters. However, in many parts of the United States,
property owners will have already developed the areas that would support new
"migrant" wetlands, and will have erected levees and bulkheads to protect dry-
land from seawater. Unless the government acts to discourage property owners
from taking measures to prevent inland retreat of coastal marshes, the United
States will lose most of these valuable wetland resources under the rising tide.

Governments may try a number of different approaches to respond to this
potential problem. These approaches may involve land use regulation to forbid
development or bulkheading behind current coastal marshes. Acquisition of
property rights (including outright (fee simple) ownership, development rights,
or leases) through purchase, condemnation, or regulation is another approach
governments may consider. James Titus has identified three categories of
strategies that the government can use to protect natural shorelines': (1)
prevent development by prohibiting it altogether or by purchasing property and
dedicating it to preservation; (2) defer action until the seas rise, and then
order landowners to abandon their property to the sea or to purchase the coastal
property; and (3) prohibit bulkheads on natural shorelines, or acquire a future
interest in coastal property. The first and third categories require the

'J.G. Titus. "Greenhouse Effect -- A Coastal Wetland Policy: How America
Might Abandon an Area the Size of Massachusetts." Environmental Management (in
press).

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Legal and Institutional Implications

government to act in anticipation of the sea level rise problem. Of the three,
the third category is the most politically feasible.

This paper discusses the legal issues that arise from applying these policy
approaches. The primary question these approaches raise is whether the
government must compensate affected property owners. The paper will focus on
the policy actions governments can take now to mitigate problems later as the
threat of land loss due to sea level rise becomes imminent. Because there is
no need to prohibit development altogether before the migration of wetlands, this
paper will focus on options that restrict bulkheading and that acquire future
interests.

The power of eminent domain, which rests in both the federal and the state
governments, allows condemnation of private property for a public purpose. The
aspects of the proposed government actions that involve purchase of property
rights face no legal barrier. Governments can negotiate a voluntary sale or
2
condemn property for the purpose of wetland protection.

This paper is concerned primarily with the extent to which governments can
act without compensating private property owners who are faced with special
restrictions or property loss. In the United States, the fifth amendment of the
Constitution, as applied to the states through the fourteenth amendment, limits
governments' ability to infringe on private property for public purposes without
3
just compensation and due process of law. Even if the best policy option is to
pay all landowners for their sacrifices to allow coastal wetlands to migrate,
an understanding of the government's authority to act without compensation will
play an important role in negotiations with private landowners. The stronger
the government's right to act without compensation, the more likely private
landowners are to cooperate, and the lower their reservation prices will be.

The fifth amendment of the U.S. Constitution specifies that people will
not be deprived of property without compensation. This limitation on government
regulations that do not compensate injured landowners is seldom encountered in
other countries. This places all of the other nations whose laws we examined
in a better negotiating position to agree with private landowners to allow
coastal wetlands to migrate.

2Wetland protection falls comfortably within the bounds the United States
Supreme Court has established to limit what constitutes a public purpose. Cf.
Berman v. Parker, 348 U.S. 26 (1954) (upholding condemnations to redevelop
blighted urban areas as within the broad state power to act on behalf of the
public welfare).

3U.S. Const. amend. V (No person shall "be deprived of life, liberty or
property, without due process of law; nor shall private property be taken for
public use, without just compensation") U.S. Const. amend. XIV, �1 (No state
shall "deprive any person of life, liberty, or property, without due process of
law").

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Fischman and St. Amand

THE "TAKING" ISSUE

In his famous 1922 opinion, Justice Holmes found that a Pennsylvania law
restricting underground coal owners from mining some of their property was
invalid without compensation to the owners for loss of their rights. 4He stated:
"if a regulation goes too far, it will be recognized as a taking." Although
subsequent cases give us a bit more guidance, Holmes' general statement
accurately captures the ad hoc law of takings -- there is no precise formula for
determining whether a regulation, such as bulkhead or development restrictions,
is a taking.5

States, which have sovereign power to regulate land use for the health,
safety, and welfare of their citizens, confer regulatory authority on local,
municipal, and county governments to control land use. Many states reserve
authority to regulate land use in areas of special concern, such as coasts.
Since state regulations and local regulations based on enabling authority granted
from the state both must respect fifth amendment protection of property, we will
not distinguish between the two in our legal analysis. However, it is important
to note that a landowner can challenge a local regulation as not being within
the scope of powers granted to the local jurisdiction by the state law. This
issue is a matter of state law, and does not arise in cases where the state
directly regulates land use, such as actions by a state coastal zone management
authority.

The policy responses to sea level rise fall into two categories for the
purpose of our takings analysis. One is permit conditions, which occur when a
government authority exacts from a landowner either an acquisition for a future
interest or a prohibition on bulkheading in exchange for the necessary permission
to develop the property. The other is bulkhead prohibitions on all property,
not tied to a grant of permission to modify land use.

Permit Conditions

Building permits for new structures are issued by local authorities who
may check to see that the proposed structure meets zoning requirements. In many
jurisdictions, special subdivision/land development ordinances regulate major

4Pennsylvania Coal Co. v. Mahon, 260 U.S. 393, 413 (1922).
5A regulation also will be invalid if it deprives a landowner of property
without due process of law. Because the due process protection in the fifth
amendment embodies similar safeguards as the just compensation requirement,
courts generally fail to distinguish between the two grounds when overturning
regulations. Want, "The Taking Defense to Wetlands Regulation," Env. L. Rptr.
(Env.L.Inst.) 10169 (1984). Therefore, the. takings issue as defined in this
paper includes due process concerns that tend to focus on the rational
relationship between the regulation in question and a legitimate government
interest (e.g., a state's interest in the health, safety, and welfare of its
citizens).

271

Legal and Institutional Implications

construction activities and often require permit applicants to meet standards
relating to environmental protection. Building on undeveloped land in coastal
zones generally requires a permit from a state coastal zone management agency.'

In fact, it was the conditioning of a permit by a coastal management agency
that the Supreme Court ruled invalid as an uncompensated taking in Nollan v.
7
California Coastal Commission. The dispute centered on a condition requiring
dedication of an easement imposed by the California Coastal Commission on a
permit to replace a bungalow with a larger house. The easement condition was
not for public access to the public beach, but for public access along the
portion of the dry sand beach owned by the permittee. The Commission argued that
the condition was imposed to mitigate the adverse impact of the new house, which
would block the public's view of the beach, "psychologically" inhibit the
public's recognition of its right of access, and increase private use of the
shorefront.

The Court found that the condition utterly failed to meet the legitimate
state interest in public health, safety, and welfare. Although the Court
suggested that a permit condition must bear a substantial relationship to a valid
public purpose, its actual finding that there was not even a rational
relationship carries more precedential weight in defining the test for permit
conditions. The Court acknowledged that the Nollans had no unfettered right to
build on the property, and that the Commission had a right to deny the permit
if denial would protect some public right.8 However, a condition on the permit
that is unrelated to the public right (of access, use, and view of the shore)
is invalid. The Commission could have conditioned the permit on the provision
of a public view or access to the beach. It could also have used its eminent
domain power to condemn the dry beach easement.

A coastal management agency seeking to protect wetlands could condition a
permit for development or construction on a prohibition of bulkheads. Because
the relationship between the presence of a bulkhead and the inability of wetlands
to migrate inland is substantial, let alone rational, such a condition would meet
the standard set by the Court in Nollan.

eThe federal Coastal Zone Management Act (CZMA), 16 U.S.C. ��1451-1464,
creates a voluntary program to encourage states to exercise their own authority
to establish and implement coastal management plans (CMPs). The CZMA is not a
grant of regulatory authority over private property to states. States with CMPs
approved by the federal government receive financial assistance and can prohibit
(subject to the veto of the U.S. Secretary of Commerce) federal activities not
consistent with the CMP. This provision gives states with CMPs leverage to
affect activities requiring federal permits, such as dredge and fill operations.
The CZMA encourages states to plan how development should occur in a coastal zone
where land use has a direct impact on coastal waters. 16 U.S.C. �1453.

7483 U.S. 825 (1987).

8483 U.S. at 836.

272

Fischman and St. Amand

Furthermore, Nollan is a case involving a physical invasion: an easement
for public access. The Court traditionally has viewed the right to exclude as
a particularly important property right protected by the fifth amendment
(regulations involving physical invasions of property often are challenged
pursuant to the fifth amendment).' A condition prohibiting bulkheads does not
invade property or give the public increased access." Given the Nollan
opinion's overall critical tone, it is important to note that it did not renounce
the validity of environmental protection (or even protection of visual
amenities)." To ensure the constitutionality of its actions, a regulatory
authority seeking to condition permits on bulkhead restrictions should make
explicitly factual findings of the relationship between the condition and the
goals of environmental protection and public welfare.

A condition requiring the transfer of a future property right (for instance,
a future conservation or flowage easement) to the government is more vulnerable
to a takings claim than a condition preventing a landowner from building a
seawall. Although the result may be the same in terms of current fastland being
inundated, the legal effect of transferring a formal property right to the
government is likely to tip the scales in favor of just compensation. If the
government builds a dam, it is required to compensate landowners for the right
to flood their land above the natural high water.

A crucial aspect of the Nollan case is that the Commission had the authority
to deny the permit entirely. Without this power, a permitting agency needs to
12
be much more careful about imposing conditions. In Nollan, conditioning
development was not such a great imposition, because a bungalow already existed

gNollan observes that the right to exclude others is "one of the most
essential sticks in the bundle of rights that are commonly characterized as
property." 483 U.S. at 831 (quoting Kaiser Aetna v. United States, 444 U.S. 164,
176 (1979)) . The Nollan Court also observed that where permanent physical
occupation has occurred, giving individuals the permanent and continuous right
to traverse the property, a taking occurs. 483 U.S. at 831-32 (citing Loretto
v. Teleprompter Manhattan CATV Corp., 458 U.S. 419, 432-33 (1982). See
discussion of Character of Government Action infra.

"At least not in the short run. In the long run, as tidelands migrate onto
private property, public rights to use the tidelands also migrate onto the
property. See discussion of State Public Trust infra.
"Sax, "Property Rights in the U.S. Supreme Court: A Status Report," 7
U.C.L.A. J.Env. L. & Policy 139, 146 (1988).
12 In fact, without the power to deny the permit, the agency may have no
authority to condition the permit. The 'Nollan opinion.offered no guidance for
determining whether an agency has the power to deny a permit in a particular
case. It is likely that the factors discussed in the next section would
determine the issue.

273

Legal and Institutional Implications

on the property, and some economic use could.'result even if the permit were
denied. Although regulations that leave property owners with no ability to build
any houses on their property have been upheld (:46e the following section), the
equities are more difficult to balance.

Bulkhead Prohibition on Existing Development

Regulation prohibiting bulkhead construction, when not tied to a permit as
a condition, is a more difficult problem. To the extent a government can ban
seawalls outright, it can certainly condition permits to that effect. On the
other hand, the power to condition permits for bulkheads (which are privileges,
not rights) does not imply an equal power to impose conditions on all landowners.
The Nollan Court, which indicated that a permit conditioned on an easement would
be valid, given a substantial relationship to a state interest, stated:
Had California simply required the Noll4n`sjo make' an easement across
their beachfront available to the public on a permanent basis in order
to increase public access to the beach, rather than conditioning their
permit to rebuild their house on their agreeing to do so, we have no
13
doubt there would have been a taking.

Nonetheless, regulation of land uses that seem more severe than a bulkhead
prohibition have been upheld by the Supreme Court. These are discussed below.
Generally, a government action is a taking if:

1. it fails to appropriately advance,a'legitimate state interest;

2. it removes all reasonable economic uses of the property; or

3. its character approaches a physical invasion. The following paragraphs
address each of these possible fatal flaws of a regulation.

Legitimate State Interest

Although some state courts have found that preservation of land in a
natural state is a valid state interest, 14 most courts look-for an interest that
is explicitly tied to human concerns. To the extent that coastal wetland
migration is important for fish spawning, for instance, a regulation advancing
this interest is more likely to be upheld if it i.s based on maintaining

"483 U.S. at 831.

14 The most famous case is Just v. Marinette Co., 201 N.W.2d 761 (Wis. 1972),
which upheld an ordinance prohibiting a landowner from filling a wetland. "The
ordinance ... preserves nature from the despoilage and harm resulting from the
unrestricted activities of humans" (201 N.W.2d at 771).

274

Fischman and St. Amand

fisheries (for humans) rather than merely protecting fish." Any legislative (or
even administrative) finding that migration of coastal wetlands is in the
interest of human health, safety, welfare, or business will help a regulation
meet the requirement that it be supported by a legitimate state interest."
Protection of noneconomic resources, such as wildlife or aesthetics, arouses
more Judicial scrutiny.

The U.S. Supreme Court has upheld regulations designed to preserve open
space, avoid premature development, and prevent pollution and congestion"';
protect wetlands"; and reclaim mines." The Court has also indicated support for
the legitimacy of a state interest in slum clearance" and visual/psychological
beach access. ,

Economic Impact
In Pennsylvania Central Transportation Co. v. New York City," the United
States Supreme Court upheld a New York City Landmarks Preservation Commission
ruling that multistory office space could not be built above the designated
landmark of Grand Central Terminal. Although the terminal's owner was denied
the ability to fully exploit the economic value of the property, the owner was
still left with a viable economic use of the property. Furthermore, city law
permitted the owner to sell air development rights to owners of nearby blocks.
The Court held that for the purposes of takings analysis, a single parcel should
not be divided into discrete segments to determine whether

'sPublic expense for maintenance of fisheries may be avoided by maintaining
wetlands (cf. 427 N.E.2d 750 (Mass. 1981) (regulations designed to avoid public
expense for flood control measures made necessary by unwise choices in land
development upheld)).

"As discussed above, such a finding is important, not only to define the
legitimate interest but also to demonstrate the nexus between the regulation
and the interest it seeks to advance.

'?Agins v. City of Tiburon, 447 U.S. 255 (1979) (upholding a zoning
ordinance limiting the number.of buildings a plaintiff could construct on his
property and deferring to legislative findings).
'aUnited States v. Riverside Bayview Homes, 474 U.S. 121 (1985) (upholding
wetland protection regulation under the federal Clean Water Act).
"Hodel v. Virginia Surface Mining and Reclamation Ass'n, 452 U.S. 264
(1981).
20Berman v. Parker, 348 U.S. 26 (1954) (upholding an exercise of eminent
domain but stating that redeveloping a blighted urban area is a legitimate police
power interest).

21 See discussion of Nollan in previous section.

22 438 U.S. 104 (1978).

275

Legal and Institutional Implications

rights in a particular segment have been entirely abrogated. In
deciding whether a particular governmental action has effected a
taking, this Court focuses rather both on the character of the action
[discussed in the next section] and on the nature and extent of the
interference with rights in the parcel as a whole."

Thus, even if an entire segment of the property bundle is destroyed, the
continued viability of other rights in the property bundle will prevent a
taking."' A large tract of land affected by a prohibition on bulkheading is
likely to be only partly inundated by advancing seas. The smaller the portion
of the land affected, the less likely the regulation is to be ruled a taking.

The Supreme Court has upheld regulations that result in a severe loss in
value, with no compensation in the form of transferrable development rights."
However, to the extent that fastland owners can be offered transferrable rights
if their land floods, regulatory authorities will increase the likelihood that
a prohibition of bulkheads will be upheld. Also helpful is a regulation
prohibiting certain uses that states explicitly what property owners may do.
Severe restrictions on land use have been upheld where the only residual
economic uses were agriculture, recreation, or camping."

The abatement of a public nuisance, even if at great expense to a private
landowner, 'more likely will be upheld than a regulation forcing a private
211
landowner to provide a public good. In this sense, the economic prong of the
takings test is related to the state interest prong. A greater diminution in

23 438 U.S. at 130-31.

24 Note: This may not be true if a court find a physical invasion, discussed
in the following section.

21 Cases quoted favorably by Penn. Central, 483 U.S. at 131 include Euclid
v. Ambler Realty Co., 272 U.S. 365 (1926) (upholding a regulation causing 75%
diminution in value of property); and Hadacheck v. Sebastian, 239 U.S. 394 (1915)
(upholding a regulation causing 87.5% diminution in value). See also the more
recent case of Keystone Bituminous Coal Ass'n v. DeBenedictis, 107 S. Ct. 1232
(1987).

21Claridge v. State Wetlands Board, 485 A.2d 287 (N.H. 1984) (camping use
for land is reasonable economic use); Turnpike Realty v. Town of Dedham, 284
N.E.2d 891 (Mass. 1972), cert. denied 409 U.S. 1108 (1973) (agriculture or
recreation are uses sufficient to surmount the taking hurdle); Turner v. DelNorte
County, 24 Cal. App. 3d 311 (1971) (recreational use sufficient).

27 Keystone Bituminous Coal Ass'n v. DeBenedictis, 107 S.Ct. 1232, 1246, n.22
(1987) (abatement of public nuisance to promote safety is not a taking, even if
it destroys the value of property).

276

Fischman and St. Amand

value is likely to be upheld if the regulation is framed as preventing harm.
Even Just v. Marinette County framed its natural wetland preservation language
in terms of preventing the public nuisance of destroying wetland value S.28

Character of Government Action

Where the government regulation is of such character as to physically
invade property, the court will find a taking, even if the economic loss is
small. In Kaiser Aetna v. United State S121 the Court ruled that the Army Corps
of Engineers could not prevent a lagoon owner from excluding the public without
compensation. In Loretto v. Teleprompter Manhattan CATV Corp.," the Court found
a taking where a New York statute required apartment owners to allow cable
companies to install facilities on their premises for a fee established by a
commission.

Once a court finds that a regulation effects a physical invasion, it
becomes extremely likely that the regulation will cause a taking. It is
critical that regulations to prevent bulkheads be drawn by making reference to
bulkheads as a nuisance to business (such as the fishing and recreation
industries) and other aspects of public welfare. A regulation that is found to
exact a flowage easement for the sea over private property is more likely to be
considered a taking than one that is found to restrict a seawall construction
activity.

Conclusion on the Takings Issue

The best rule of thumb for deciding whether outright bulkheads will be a
taking is to return to Justice Holmes' pronouncement that a regulation that goes
"too far" is a taking. Whether a regulation goes "too far" depends on the
circumstances of the particular case. A bulkhead prohibition will most likely
be upheld if it:

� advances public health, safety, or welfare (including business)
interests;

� is based on a legislative finding that ties the regulation to the health,
safety, and welfare interests;

28201 N.W.2d 761 (Wis. 1972) See also Miller v. Schoene, 276 U.S. 272
(1928) (upholding ordinance requiring landowners to cut down their cedar trees
to protect apple trees from being affected by disease); Hadacheck v. Sebastian,
239 U.S. 394 (1915) (upholding a local decision to ban a brickyard because of
the nuisance it creates to surrounding residences that were erected while the
brickyard was operating).

29444 U.S. 164 (1979).

30458 U.S. 417 (1982).

277

Legal and Institutional Implications

� treats interference with a migrating wetland as a nuisance;

� leaves landowners with some viable economic use of their land; or

� provides some sort of transferrable right to ease the economic burden on
affected landowners.

A policy to prohibit use of bulkheads for property just now being developed
(as opposed to applying it to all property) can be implemented by using a pre-
existing regulatory system to condition permits. An anti -bul kheading condition
will be upheld if it appropriately advances a state interest and if the
underlying permit has not already been vested as a right in the landowner's
property. ,

THE PUBLIC TRUST DOCTRINE

We have seen that regulation designed to restrict land use to allow coastal
wetland migration must not run afoul of the fifth amendment. However, because
wetlands are valuable natural resources in which the public has a substantial
interest 3' a government may be able to act within its trust responsibilities to
address sea level rise. Furthermore, the law recognizes the coastline as a
uniquely important location and grants the government special rights and
responsibilities to act on the coast in the public interest.

The public interest is a legal doctrine with ancient roots that concerns
inalienable common rights to use certain natural resources. There is no single
public trust theory; different trusts operate for different resources and
different sovereigns (state and federal). State and federal public trust
doctrines are relevant to considering responses to sea level rise because the
coast is an area where private lands traditionally have been subject to public
rights. Furthermore, protection of these public rights may be an affirmative
duty for governments.

Federal Public Trust: The Navigational Servitude

Pursuant to the commerce clause of the U.S. Constitution, the federal
government impresses a servitude on all navigable waters. To ensure free
commerce, navigation, and fishing, the federal government can improve both
inland and coastal waters by building dams, jetties, diversions, etc. Private
property owners who are injured by loss of the benefits of access to water due
to these federal improvements have no legal recourse.

The commerce clause, besides defining the scope of the federal navigational
servitude, also defines congressional regulatory authority over navigable

31 Important wetland functions include flood control; habitat for fishing,
hunting, and recreation; and sediment, erosion, and pollution control. See J.A.
Kusler. Our National Wetland Heritage: A Protection Guidebook. 1-7 (1983).

278

Fischman and St. Amand

waters. This regulatory authority is broader than the navigational servitude,"
and its exercise by Congress may sometimes require compensation under the fifth
33
amendment. For instance, in Kaiser Aetna v. United States, the Court ruled
that a non-navigable private fish pond, when dredged and connected to the ocean
to create a marina, is subject to the U.S. Army Corps of Engineers' regulatory

authority, but not to the federal navigational servitude, which would have
required free public access to the marina without compensation to the owner.

The commerce clause authorizes Congress to exercise eminent domain to
provide public access, so long as the owner is compensated. However, a federal
action that alters access to waters subject to the navigational servitude, even
if the alteration completely deprives a littoral owner of all access to the
waters, does not require compensation. This is because the owner's title has
never been so complete as to include continued enjoyment of the benefits of
access to navigational waters. Even when the government condemns fastlands for
a water-related project, compensation to the owner does not include the value
of those lands attributable to their location near the water, such as for a
port. "

The federal government could use the navigational servitude to prohibit a
littoral landowner from erecting a bulkhead below the high-tide line, and no
compensation would be required. The federal government could use its broader
commerce clause regulatory authority to ban fastland bulkheads; however, it
would be required to compensate the landowner if the regulation resulted in a
taking. As seas rise, there is no question about the federal government's
ability to ensure that coastal wetlands be allowed to migrate. The difficult
question is whether the federal government also could exercise its authority to
31
prohibit bulkheads without compensating inundated landowners. Would the
Supreme court hold that the navigational servitude migrates inland as the seas
rise?

"In fact, Congress' authority to regulate interstate commerce is much
broader than the federal navigational servitude. Not only can Congress regulate
waters that are non-navigable, it can regulate virtually any class of economic
activities that cumulatively affect interstate commerce. Wickard v. Filburn,
317 U.S. 111 (1942) (upholding regulation of farmer's production of wheat for
his family's consumption); United States v. Darby, 312 U.S. 100 (1941) (upholding
exclusion of certain goods manufactured by factories violating labor standards
from interstate commerce).

33 444 U.S. 164 (1979).

31 United States v. Rands, 389 U.S. 121 (1967).
"Landowners who delay in building a bulkhead and find their property partly
under water during high tide may lose some rights to exclude the sea from that
area. The following discussion concerns the situation where a landowner builds
a bulkhead before the property is inundated.

279

Legal and Institutional Implications

Courts could decide the issue either way. Kaiser Aetna and its companion
case, Vaughn v. Vermilion, 36 indicate that the Court will focus on past use of
areas that become subject to the ebb and flow of the tides as a result of
private construction. In both cases, a landowner altered property that was not
navigable to make it navigable for private use, In both cases, the Court held
that such improvements did not result in the extension of the federal
navigational servitude to cover the new navigable waters. Therefore, a
landowner who, in order to protect existing fastland, erects a bulkhead to keep
a rising sea at bay will probably retain all of his private rights, even if the
sea level rises to a point where it would otherwise inundate the fastland.
Current Court doctrine seems to support the principle that land not previously
subject to the navigational servitude will not be impressed with a new servitude
due to artificial construction. Since construction of a bulkhead will prevent
the land from becoming subject to the ebb and flow of the tides, the land will
remain free from the servitude. It is hard to see how a Court that does not
recognize the migration of the federal navigational servitude to an area that
becomes navigable-in-fact would extend the public trust to an area that is kept
dry by a seawall.

Nonetheless, the Court has not addressed the issue of whether landowners
can avoid a servitude by keeping the sea off their property under a condition
where inaction would result in an expansion of the servitude. In Kaiser Aetna
and Vaughn, the inaction would not have resulted in an expansion of navigable
waters. The Court did not wish to penalize enterprising landowners who expand
navigable waters through construction. Where inaction will result in rising sea
levels moving navigational waters upland, the Court may find that the servitude
moves, regardless of construction activities. In a sense, this interpretation
of the reach of the navigational servitude is tied to the "natural" reach of
navigable waters in the absence of construction. This interpretation is
consistent with a policy of promoting an increase in navigable waters, evinced
37
in Kaiser Aetna and Vaughn.

The Vaughn opinion left open the question of whether diversion or
destruction of a pre-existing natural waterway concomitant to the construction
activity that, on its own, does not alter the reach of the navigational
servitude, would result in extending the servitude to the new navigable area
created at the "expense" of part of the public servitude. 38 If harm to pre-
existing navigable waters extends the servitude, then bulkheading that results
in the degradation of navigable waters (perhaps including wetlands) may be
subject to the public trust.

38444 U.S. 206 (1979).

37If the Court had found that the navigational servitude had moved in these
cases, property owners would be discouraged from expanding navigable waters
because they could not capture the benefits.

38 444 U.S. at 208-10.

280

Fischman and St. Amand

Because the Court has not dealt with a case involving areas where navigable
seas inundated former fastland,"' the extension of the navigational servitude is
speculative. Does the human-induced nature of global w 'arming change the
analysis? Does an artificial seawall constructed to block an "artificial" rise
in the sea level result in no net loss of property rights to the landowner? Or,
does the potential loss of public rights trump private rights? These are
questions the Court is certain to face in the future.

State Public Trust

As inheritors of the sovereign rights of the Crown, the thirteen original
states acquired ownership of all lands subject to the ebb and flow of the tide.
The "equal footing" doctrine has granted all subsequent states the same rights
as the original thirteen .40 Therefore, upon statehood, each state received title
to lands under the high-tide mark .4' The public trust prevents the federal
government from conveying title to tidelands either before statehood or after.
States may own submerged tidelands, regardless of their navigabil i ty.42
Where the federal public trust is primarily concerned with free navigation

"Hughes v. Washington, 389 U.S. 290 (1967), distinguished between the
effects of changes in a river course and changes in the sea shoreline. Sea
shorelines are sufficiently important to justify a federal rule governing
ownership resulting from accretion and erosion where title rests with or is
derived form the federal government. California ex rel. State Lands Commission
v. United States, 457 U.S. 273, 282-83 (1982) (interpreting Hughes and Wilson
v. Omaha Indian Tribe, 442 U.S. 653 (1979)). Ownership of land involved in
changes in river courses, so long as they do not affect state boundaries, is a
matter of state law.

41pol lard's Lesee v. Hagan, 3 How. 212 (1845).

41 Shively v. Bowlby, 152 U.S. 1 (1894). (States also received title to beds
underlying navigable waters not subject to the tide by extension of the English
law doctrine. The Propeller Genesee Chief v. FitZhu h, 12 How. 443 (1852)).
gL

41 Phillips Petroleum Co. v. Mississigpi, 108 S.Ct. 791 (1988). Not all
states own submerged tidelands (it is a matter of state law). However, all
submerged tidelands, whether publicly or privately owned, are subject to certain
public easements. See, e.g., Bell v. Town of Wells, 57 U.S.L.W. 2590 (Maine Sup.
Jud. Ct. No. 5029 3/30/89) (intertidal landowners hold title in fee subject to
public easements); People v. California Fish Co.., 138 P. 79, 88 (Cal. 1913)
(private ownership subject to a paramount right to use by the public).
Generally, though, state public trust lands extend from the mean high-tide
line (otherwise known as the mean high-water mark) seaward to the three-mile
territorial limit. This public trust land includes tidelands (otherwise known
as foreshore) from mean high tide to mean low tide and submerged lands seaward
of the low tide. Existing wetlands generally fall in tidelands. Comment,
"Public Access to Private Beaches: A Tidal Necessity," 6 U.C.L.A.J.Env. L. &
Policy 69.

281

Legal and Institutional Implications

issues, state public trust is more expansive and is concerned with a wide
variety of interests, including fishing rights, environmental quality, and
recreation .4' Therefore, state doctrines of public trust are more helpful than
the federal doctrine in protecting the public interest in wetlands preservation.
States hold submerged tidelands for public purposes.

Rather than being a single doctrine, state public trust is fifty separate
bodies of law, each created by a state. Whether a rise in sea level will add
to state public trust land at the expense of private landowners is entirely a
question of state law." In this paper we will discuss the State of Mississippi
because of (1) its involvement in an important, recent Supreme Court case; (2)
its shore location on the Gulf of Mexico with extensive wetlands; and (3) its
representative common law system (as contrasted with the State of Louisiana's
system, which is influenced by civil law).

Mississippi's Public Trust

Mississippi's public trust in submerged lands, vindicated by Phillips
41
Petroleum, includes an interest in public bathing, swimming, recreation,
fishing, environmental protection, and mineral development." Despite the fact
that Phillips Petroleum Co. had been paying property taxes on submerged lands
for which it had recorded title, the Court held that the submerged lands (and
their valuable mineral rights) belonged to the State of Mississippi, which had
never granted the company the rights it was claiming.
The Mississippi Supreme Court, in Cingue Bambini Partnership v. State,""
held that state public trust lands may be augmented by

natural inland expansion of the tidal influence... If over
decades ... the tides rise -- that is, the mean high water mark rises
(and there is reason to believe this has happened and may continue to
happen) -- the inward reach of the tidal influence expands ... [T]he
new tidelands so affected accrete to the trust.

"See, e.g., Marks v. Whitney, 491 P.2d 374, 380 (1971).

"Oregon ex re. State Land Board v. Corvallis Sand and Gravel Co., 429 U.S.
363 (1977).

45 108 S.Ct. 791 (1988).

46E.g., Treuting v. Bridge and Park Comm'n of City of Biloxi, 199 So. 2d
627, 632-33 (Miss. 1967); Miss. code Ann. �� 49-27-3 and -5(a) (Supp 1985) (cited
in Cingue Bambini Partnershig v. State, 491 So. 2d 508, 512 (Miss. 1986), aff'd
Phillips Petroleum, 108 S. Ct. 791 (1988)).

47 491 So. 2d 508, 519-20 (Miss. 1986), aff'd Phillips Petroleum Co., 108
S.Ct. 791 (1988).

282

Fischman and St. Amand

On the other hand, artificially created water courses, inlets, marinas,
and other non-natural alterations to private land do not cause ownership to pass
to the state public trust, even though they become subject to the ebb and flow
of the tides. This finding was not appealed to the U.S. Supreme Court with the
other issues in Phillips Petroleum.

Therefore, in Mississippi, as seas rise, ownership of new submerged land
passes to the state. However, there is no existing state legal doctrine that
imposes a public interest in lands that lie below sea level but that are not
subject to the ebb and flow of the tides due to bulkhead protection. Also, to
the extent that one could argue that sea level rise caused by the greenhouse
effect is not a natural event, then the state may not be entitled even to the
submerged land. However, the natural/artificial distinction seems to be as much
based on rate of change as anything else. Since sea level rise will occur
slowly (over the course of decades), it may be regarded as a natural change
because of the gradual way the alteration to the shoreline occurs.

The Expanding Public Trust

Since the 1970s, many courts and commentators have argued that the public
trust doctrines should reach beyond the federal navigational servitude and state
ownership of submerged lands to protect public rights to certain natural
resources incapable of or inappropriate for private ownership." As the modern
public trust doctrines evolve along with the problems posed by increased coastal
wetland loss from rising seas, the reach of public rights may extend to
privately owned fastlands. Some courts view the public trust as a dynamic
doctrine to "be molded and extended to meet changing conditions and ... (that] was

4'The seminal article that reinvigorated the public trust doctrine is Sax,
"The Public Trust Doctrine in Natural Resource Law: Effective Judicial
Intervention," 58 Mich.L.Rev. 473 (1970). See also Sax, "Liberating the Public
Trust from Its Historical Shackles," 14 U.C.D.L.Rev. 185 (1980); Stevens, "The
Public Trust: A Sovereign's Ancient Prerogative Becomes the People's
Environmental Right," 14 U.C.D.L.Rev. 195 (1980). Criticizing the expansion of
the public trust doctrine at the expense of private property rights are Huffman
"Avoiding the Takings Clause Through the Myth of Public Rights: The Public Trust
and Reserved Rights Doctrines as Work," 3 Fla.St.U.L.Rev. 171 (1987); rose, "The
Comedy of the Commons: Custom, Commerce, and Inherently Public Property," 53
U.Chi.L.Rev. 711 (1986).
The most widely cited court decision implementing the broader notions of
the public trust is National Audubon Society v. Superior Court of Alpine Co.,
658 P.2d 709 (Cal.), cert. denied 104 S. Ct. 413 (1983) (incorporating public
trust considerations into the existing state system of water rights by balancing
reasonable, beneficial uses of water with competing public interests, such as
environmental protection). See National Audubon Society v. Department of Water,
858 F.2d 1409 (9th Cir. 1988) for the latest case in the ongoing Mono Lake
controversy.

283

Legal and Institutional Implications

created to benefit [the needs of the public]."" To the extent that the public
has a right to enjoy the benefits of coastal wetlands, a trust may exist to
ensure that those wetlands do not disappear under the rising seas.

The past two decades have seen the greatest expansion of the public trust
right in the area of recreation. Where the traditional public trust extended
only up to the high-water line and was concerned with navigation, commerce, and
fishing, recent cases have expanded the trust to include dry-sand areas of
public beaches for recreation." The extension of the public trust in the State
of New Jersey above the high-water mark to the area of dry sand that lies
landward of the high-water mark to the vegetation line (or artificial barrier)
presents an interesting analogy to the problem of migrant wetland protection.

In Matthews v. Bay Head Improvement Ass'n,s' the New Jersey Supreme Court
confirmed that the public's right to use tidelands includes a variety of
recreational activities .52 It found that the use of the dry-sand beach
immediately above the high-water mark was necessary to the exercise of the
public right. This ancillary right includes not only the right to use the dry-
sand beach for access to the tideland, but also "the right to sunbathe and
generally enjoy recreational activities. 11,13 The court declared that this right
of use of the dry-sand beach exists on private as well as public lands." The
public use must be reasonable, and we may expect that some uses that are
reasonable on public lands are not reasonable on private lands. Nonetheless,

"Borough of Neptune City v. Borough of Avon-by-the-Sea, 294 A.2d 47, 54
(N.J. 1972) (quoted in Matthews v. Bay Head Improvement Ass'n, 471 A.2d 355, 365
(N.J.), cert. denied 105 S.Ct. 93 (1984)). See also, Marks v. Whitney, 491 P.2d
374, 380 (Cal. 1971) ("The public uses to which tidelands are subject are
sufficiently flexible to encompass changing public needs.").

'OSee e.g., Matthews v. Bay Head Improvement Ass'n, 471 A.2d 355, 365
(N.J.), cert. denied 105 S.Ct. 93 (1984). Not all states share an expansive view
of the public trust. A recent case in the State of Maine held that a legislative
determination that intertidal lands (held in fee by private landowners with a
traditional public easement for fishing, fowling, and navigation) are impressed
by a public trust that includes a right to recreate is a physical invasion of
private property that requires compensation of landowners. Bel 1 v. Town of
Wells, 57 U.S.L.W. 2590 (Maine Sup. Jud. Ct. No. 5029 3/30/89).

5'471 A.2d 355 (N.J.), cert. denied 105 S.Ct. 93 (1984).

52 See Borough of Neptune City v. Borough of Avon - by-the-Sea, 294 A.2d 47
(N.J. 1972).

13 471 A.2d at 364.

54 In fact, the defendant in the case was a non-profit corporation that acted
as a quasi-public association. The court's language regarding purely private
dry-sand beaches is dictum.

284

Fischman and St. Amand

the court's tjillingness to impose public rights on private lands to allow public
enjoyment of existing public trust lands indicates a flexibility that holds
promise for providing a basis for imposing public trust restrictions - on
fastlands located upland of existing coastal wetlands.

Wisconsin, in its celebrated but not widely followed opinion of Just v.
Marinette Co.,,,5' declared ecological stability to be a public trust imposed on
private lands. @n Just, a landowner was prevented from building on his land
because of its ecological importance as a natural wetland. Because destruction
of a wetland injures others by upsetting the natural environment, it can be
considered a nuisance. Abating a nuisance is not a taking. California has a
similar ecological interest in its public trust doctrine for tidelands." It is
important "6o note that there is a difference between prohibiting development of
a tract of land because of its existing value as a wetland and prohibiting the
erectien of a seaviall because of a tract of land's potential to evolve into a
wetland. Ot-sners are on notice of the natural character of their land, but not
necessarily of its importance as a future wetland if the sea level rises. As
Professor Sax points out, the sea level rise situation is analogous to
prohibiting a woodland owner from fighting a forest fire on his property because
of the benefits to wildlife."

Enforcing the Public Trust

Although our consideration of the public trust has been with an eye toward
finding authority for willing state and federal governments to claim a public
interest in protecting migrating coastal wetlands, the public trust is sometimes
applied to compel a government to take or refrain from an action. The classic
case of this application of the trust is Illinois Central Railroad v. Illinois,"
where the Court declared invalid a state legislative grant of title to the
railroad for a major section of the Chicago waterfront. The state was powerless
to alienate a natural resource as important as Chicago's harbor. Although there
are exceptions to the rule against alienation of the public trust in the event

55201 H.W.2d 761 (Wis. 1972).
"Marks v. Whitney, 491 P.2d 374, 380 (Cal. 1971) ("(O]ne of the most
important public uses of the tidelands ... is the preservation of those lands in
their natural state, so that they may serve as ecological units...").
57j. Sax, unpublished typescript, (undated) (on file with authors). Cf.
Miller v. Schoene, 276 U.S. 272 (1928) where a landowner was forced to destroy
trees to protect a local apple industry from harm. Forcing landowners to refrain
from building bulkheads to benefit the industries (such as commercial fishing)
that depend on coastal wetland ecosystems is analogous to the Miller situation,
which resulted in no taking.
581 46 U.S. 387 (1892).

285

Legal and Institutional Implications

the transfer is for a public purpose,'59 state inaction that leads to seawalls
that stop the natural migration of the public trust may be viewed as an improper
abdication of the public trust.

If the government does have the power to prohibit bulkheads, then it may
be required to exercise that power to fulfill its public trust responsibilities.
In a series of cases relating to the U.S. Department of the Interior's
management of Redwood National Park,"' a federal district court found that the
department failed to meet its fiduciary responsibilities to protect the park and
required it to fulfill its trust by lobbying Congress for an expansion of park
boundaries. The court ordered the department to report back to the court on
proposals made for more park protection, more management authority, more money
to purchase land, and more negotiation of cooperative agreements with
neighboring timber companies (whose practices were causing erosion and
sedimentation).

Although the situation with coastal wetland migration differs from these
two examples in that publicly owned land is not involved, it is similar in that
public rights are at stake. The fiduciary duties may arise from different
sources, but if the trust exists, these cases indicate that it is enforceable
against the government.

Conclusion on the Public Trust Doctrine

Under the traditional view of the public trust, states that assert public
ownership of intertidal lands may gain control of new wetlands only if
landowners let their property fall under the influence of the tide. This is a
matter of state law. However, property owners who build seawalls before their
land is inundated will most likely be protected by the fifth amendment. The
Kaiser Aetna case warns that, at least in the case of the federal navigational
servitude, public trust authority does not exempt the government from its
obligation to compensate a landowner for a taking. The public trust does not
offer an easy solution to the difficult problem of responding to landowners who
wish to keep back the sea with bulkheads.

Professor Sax describes the primary justification of the modern public
trust doctrine that protects a wide variety of public resources as "preventing
the destabilizing disappointment of expectations held in common but without

59See e.g, City of Milwaukee v. State, 193 Wis. 423 (1927) (upholding
Milwaukee's grant to a steel company to develop a public harbor).
OoSierra Club v. Department of Interior, 424 F. Supp. 172 (N.D. Cal. 1976),
398 F. Supp. 284 (N.D. Cal. 1975), 376 F. Supp. 90 (1974). See Wilkinson, The
Public Trust Doctrine in Public Land Law, 14 U.C.D.L.Rev. 260 (1980) for a
probing analysis of these cases.

286

Fischman and St. Amand

formal recognition such as title."' Few courts have recognized explicitly such
a broad public right over private property. Even those jurisdictions that have
recognized broad public rights, such as New Jersey and Wisconsin, give little
indication that they would extend the right to landowners who wish to protect
the existing character of their property.

However, if the public trust lives up to its potential as described by Sax,
it may be an effective tool in the future for asserting a public right to the
continuing enjoyment of the benefits of coastal land. The changing
circumstances to which a flexible doctrine must adapt62 may demand an explicit
recognition of the public values served by our threatened natural systems. The
most effective strategy today for encouraging this evolution in the doctrine is
to put private landowners on notice of the importance that the public places on
coastal wetlands and of the role that fastlands will play in the future
viability of marsh ecosystems.

LEGAL MECHANISMS AVAILABLE IN OTHER COUNTRIES

While application of the legal regime in the United States to the migration
of coastal wetlands is the primary focus of this paper, the preservation of
wetland ecosystems in the face of rising sea levels is an issue confronting many
nations. Legal systems, however, vary in their treatment of property rights and
coastal protection, and conservation mechanisms available in one nation may lack
a legislative or constitutional basis in another. Accordingly, current laws
that may enable the conservation of coastal lands adjacent to existing wetlands
in several Atlantic Basin countries are briefly discussed below as examples of
the adaptability of different legal regimes to meet this problem.

Argentina

Provincial Authority

In Argentina, all of the area seaward of the mean high tide line, including
coastal wetlands, is within the public domain. This littoral region is
generally under the jurisdiction of the provincial government, although the
federal government has jurisdiction over activities affecting navigational uses.
There are four provinces on the Atlantic Coast and two federal territories--the
city of Buenos Aires and Tierra del Fuego. The provinces and the federal
territories both have authority to regulate land use and to protect natural
resources. Private property rights adhere only inland of the mean high-tides
line, and development is prohibited within the public domain, unless expressly

81"Liberating the Public Trust Doctrine From it Historical Shackles," 14
U.C.D.L.Rev. 185, 188 (1980).
12 See Borough of Neptune City v. Borough of Avon-by-the-Sea, 294 A.2d 47,
54 (N.S-. 1972) (quoted in Matthews v. Bay Head Improvement Ass'n, 471 A.2d 355,
365 (N.J.), cert. denied 105 S.Ct. 93 (1984)).

287

Legal and Institutional Implications

permitted by the government .63 It appears that in the area below the mean high-
tide line, provinces can easily prevent the building of seawalls and jetties,
which would inhibit the migration of coastal,wetlands.

Conservation of land inland of the mean high-tide line, however, may
require compensation. Expropriation of private property requires full
indemnification under the Argentine Constitution. The creation of upland parks
or reserves to enable the migration of coastal wetlands would, therefore,
clearly require compensation. However, land use restrictions imposed upon
private property in the public interest do not require compensation, unless such
restrictions imply the creation of an easement or servitude.64 The Province of
Buenos Aires has established a zone 150 meters inland of the mean high-tide line
in which subdivision and construction are prohibitede,5; this regulation does not
require compensation.

To the extent that prohibitions on building seawalls and jetties result in
the inundation of private lands due to rising sea level, Argentine case law
indicates that this would not be considered expropriation, but rather
noncompensable damage attributable to natural forces.

Federal Navigation Law

As mentioned above, the federal government has authority over the
navigational uses of waterways. Under federal navigation law, owners of
property along navigable rivers or channels apart from the seashore are
prohibited from developing a 35-meter-wide "towpath" area adjacent to the river
bed. " Riverside landowners do not receive any compensation for this
restriction, since the limitation is considered to have adhered to the property
67
in remote time. If the river changes course due to natural causes, such as a
rise in sea level, this protected zone would migrate inland. This riparian
provision may be used to allow migration of estuarine wetlands.

Flood Control Law

The Executive Branch ofthe Argentine government may, through its authority
to issue executive decrees, define floodplains and floodprone areas, establish
land use restrictions for these areas, and require the demolition of obstacles

"See Codigo Civil (Civil code), art. 2340.

84 See G. Cano, Legal and Institutional Implications of Adagtive Options o
Sea Level Rise in Argentina, Uruguay and Spain (1989).

8"Decree 9196/50.

OeCodigo Civil, arts. 2639, 2640.

67 See National Constitution, arts. 14, 17.

288

Fischman and St. Amand

to the free runoff of water." In addition, loans and subsidies may be
established for the resettlement of inhabitants displaced as a result of floods.
The use of this executive authority, which is in some cases subject to
legislative approval, could assist in enabling the migration of coastal
wetlands.

Brazil

Brazil's new Constitution declares the coastal zone to be a resource of
"national heritage," the use of which must be under conditions that ensure its
preservation." How the government intends to implement fully this
constitutional provision is not yet clear, but there are several existing
statutory provisions that could be used to preserve coastal wetlands as sea
level rises.

First, the Codigo Florestal (Forestry Code) has been interpreted to
prohibit any use of mangrove swamps throughout the country." Second, all flora
and fauna are considered property of the federal government, which can restrict
the use of pr 7ivate property in order to preserve areas important for species'
conservation.' Therefore, the government has the power, for example, to
prohibit the building of seawalls to conserve areas for future breeding sites
for waterfowl. Such land use restrictions do not require any indemnification,
although expropriation for conservation purposes would require the payment of
compensation to affected landowners. Third, all beaches are considered to be
in the public domain, and no use of the land adjacent to the beach may hinder
'12
the public's access.

Canada

Land Use Controls

In Canada, protection of natural resources, including coastal wetlands, is
primarily the responsibility of provincial governments. The authority to
institute land use controls also resides with the provinces, including the power
to enact legislation prohibiting the construction of seawalls or otherwise
limiting development to permit the inward migration of coastal wetlands. The
provinces may delegate planning and zoning authority to municipalities.

68Codigo Civil, art. 2611.

"Constitution of 1988, tit. VII, ch. VI, item VIII, para 4.

70S ee Codigo Florestal, law 4771 of Sept. 15, 1965, art. 2, items a.3 and

"'See Federal Law 5197 of January 3, 1967; Codigo Florestal, art. 1.

72C onstitution of 1988, tit. III, ch. II, art. 20, item IV.

289

Legal and Institutional Implications

The Canadian Constitution does not require the Dominion or the provinces
to pay compensation when private lands are expropriated for public purposes."
Although expropriation without compensation is legal, a common law presumption
in favor of compensation does exist in the absence of any express legislative
'14
provision for confiscation without compensation. In addition, the provincial
legislatures have instituted Expropriation Acts, which authorize compensation
for the confiscation of private property.

Despite the existence of the presumption in favor of compensation and the
Expropriation Acts, a province can legally enact legislation that both provides
for the confiscation of coastal lands adjacent to threatened wetlands and
specifies that no compensation will be paid. Of course, the question remains
as to whether such legislation would be politically feasible, especially given
the tradition of compensation upon expropriation.

Land use restrictions that may affect a landowner's economic interests,
but that do not amount to an expropriation, do not carry a presumption in favor
of compensation." Provinces or municipalities may prohibit development that
would prevent inward migration of coastal wetlands, such as the building of sea-
walls or jetties. Such legislation does not need to specify 78 compensation for
any economic loss suffered as a result of those restrictions. In contrast to
the expectation of compensation upon expropriation, there is no tradition of
"takings" law in Canada, and the public is more accepting of stringent land use
77
controls without compensation than it is in the United States.

An example of existing restrictions that could be used to conserve coastal
uplands in anticipation of wetlands migration is found in Quebec Province. The
Quebec Expropriation Act provides that privately owned land may be reserved for
public purposes and cannot be developed for a specified number of years. The
statute, however, does provide the affected landowner with compensation .7' Such
a provision could be applied to the conservation of uplands adjacent to current
coastal wetlands.

73 E.C.E. Todd, The Law of Expropriation and Compensation in Canada 32
(1976); G.S. Challies, The Law of Expropriation 75 (1963).

114 Challies at 33.

71 See Todd at 24-25.

76 Id. at 25.

71Conversation with Dr. Jim McCuaig, Canadian Wildlife Service, November 16,
1989.

7'Todd at 12.

290

Fischman and St. Amand

England

Land Use Controls

In England, the national town and country planning legislation vests in
the state and its agencies, the local planning authorities, all rights to
develop land."' Before developing any land, a landowner must obtain planning
permission from a government agency, which can be local or central." No
compensation is due to a landowner who is unable to obtain planning permission."
It follows that local and national government agencies may prohibit development
of lands adjacent to existing coastal wetlands without providing any
compensation.

Expropriation of private lands, however, does require the payment of
compensation to the landowner."' In addition, if planning permission has been
withheld and, as a result, a landowner's property is rendered incapable of
reasonably beneficial use, the landowner may serve a purchase notice on the
district planning authority." Similarly, if planning proposals cause a dwelling
114
to become unsalable, the owner may serve a blight notice. In either case, the
planning authority is then required to purchase the property for the existing
use value." It follows that landowners would attempt to obtain compensation if
a planning authority's refusal to permit the construction of seawalls or jetties
caused or threatened to cause the inundation of their property. Since the
actual inundation is an act of natural forces, however, it is unlikely that the
landowners would prevail.

Coastal Protection

The idea of conservation of coastal lands is well established in England.
A national agency, the Nature Conservancy Council, assists in the management of
undeveloped coastal areas. The Council may establish, maintain, and manage
11natural reserves," which are areas that provide special opportunities for the

"Garner, 1986, "Town and Country Planning Law in England and Wales," J.F.
Garner and N.P. Gravells (eds.), Planning L. in West. Eur. 125.

"Id. at 125.

81Id.

"Id. at 124-125.

83 Id. at 127.

'41d.

86M.

291

Legal and Institutional Implications

study, research, and preservation of flora and fauna.88 The Council may also
designate areas to be of "special scientific interest" by reason of their flora,
fauna, or geological or physiological features.87 While an area of such interest
may be under private ownership, the landowner is prohibited from carrying out
activities that are likely to damage the features -of interest without receiving
the Council's consent.88 Both nature reserves and special scientific interest
areas may be used to conserve land inland of threatened coastal wetlands.

Most of the authority to manage coastal. lands, however, rests with the
local County and District councils. In 1972, the Department of the Environment
asked the County councils to designate stretches of nationally outstanding
"heritage coast" and to provide in their land use plans for the long-term
conservation and management of these coastal lands."" Approximately 40 percent
of the undeveloped coast is designated as "heritage coast."go County plans vary,
but, for example, the County of Kent's plan provides that unspoiled coastal
areas and their adjoining countryside are protected from development that would
detract from their scenic or scientific value." This county plan clearly would
assist in enabling coastal wetlands to migrate to the "adjoining countryside."

In addition, voluntary organizations are also active in the protection of
English coastal lands. The Royal Society for the Protection of Birds manages
in excess of 70 reserves, while the National Trust manages almost 1000 square
112
kilometers of coastal lands. The National Trust was created through an Act of
Parliament, but is supported through private subscriptions, donations, and
bequests. Tax concessions are given to private landowners in exchange for
113
property bequests.

"Burton and Freestone, 1988. Legal Regulation of the Humber, The Humber
Estuary: Environmental Background 87.

87 Id. at 67.

881d.

"'Waite, 1981. "Coastal Management in England and Wales." In ComRarative
Marine Policy 66.

gold .at 67.

Old.

92 Id. at 67.

13 Id. at 73-74.

292

Fischman and St. Amand

France

Planning Code

While government expropriation of land entitles the landowner to
compensation in France, land use restrictions may be instituted without
94
indemnification. Amendments to France's Planning Code in 1986 created a new
chapter, which requires local authorities in littoral zones to take into account
the conservation of coastal ecosystems of special interest, including wetlands,
estuaries, marshes, and breeding sites.9,5 In addition, any activities permitted
on or near the coastline must allow for public access to the shore." In
undeveloped areas, no building is permitted within 100 meters inland of the
highest point on the shoreline, and local authorities may extend this zone . 97
New highways must be placed at least two kilometers from the shoreline, and
local roads cannot hug the coast unless required by geographical necessity."
Any act adversely affecting the natural seashore, such as the construction of
seawalls or jetties, is prohibited, unless it is certified as in the public
interest and required by the site's topography.9" By protecting the coastal
lands adjacent to the shoreline, the Planning Code's restrictions on development
allow the migration of wetlands.

Natural Fragile Areas

The French political subdivisions, known as Departments, also have the
ability to designate natural fragile areas where camping and building are
prohibited. These areas may also be acquired through pre-emption (meaning the
state has preference over all other buyers), after which they must be kept open
to the @ublic. Natural fragile areas are purchases through a tax on building
permits. 00 Of 25 coastal departments, 22 have designated natural fragile areas,
and this mechanism could be used to conserve sensitive lands just inland of
coastal wetlands.

94 See Besson-Guillaumot, "Town and Country Planning France," J.F. Garner and
N.P. Gravells (eds.) in Planning L. West. Eur. 153.
"'Foster, 1986. "Current Legal Developments: France," Int.J. Estuarine &
Coastal L. p. 309.

98Id. at 310.

97 Id.

98Id.

99Id.

"'Prieur, 1988. "France: A Step Towards Comprehensive Programmes for
Coastal Areas in France," Int.J. Estuarine & Coastal L. 3:161.

293

Legal and Institutional Implications

Seashore Conservatory

In 1975, France created a national agency called the Seashore Conservatory,
which has the power to acquire coastal lands for ecological protection. The
Conservatory's main objectives are to purchase natural coastal areas threatened
by development; to set priorities for sites according to their ecology,
geography, or l.andscape; and to preserve coastal agricultural lands."' The
Conservatory may acguire land by negotiated purchase, pre-emption, eminent
2
domain, or donation. Conservatory land must be kept open to the public. The
Conservatory's authority, especially its ability to preserve coastal
agricultural lands, is easily adaptable to the problem of wetland migration.

Nigeria

The law concerning Nigeria's Atlantic coast is contained in a few statutes
and a handful of common law cases that deal with the rights of ownership and the
usage of coastal zones. Some provisions and precedents may be applied to the
issue of coastal wetlands migration.

The Public Lands Acquisition Act lists the public purposes for which
private land may be expropriated, including general public use, and provides for
compensation. Under the.Land Titles Registration Law, the foreshore is in the
public domain, unless excepted in the land titles register."' Likewise, the
state also has title to beach land. 104 The government, therefore, has the
authority to prohibit construction of seawalls or jetties along the coast. In
addition, one commentator states that as the sea "advances further into the land
of the riparian owner, that part of his land that is swallowed by the sea
together with the new high-water level belongs to the State.11105

However, the government also recognizes the customary rights of usage of
the foreshore and beach by the local indigenous people as a community. While
the state retains title to these areas, local customary ownership interests
prevail over individual control. Case law establishes that individuals or
private companies will be denied exclusive property and usage 6rights to coastal
land on the grounds that such land is communal in nature." It is unclear,
however, whether government restrictions on the building of seawalls or jetties

10'Id.

102 Id.

103 T.O. Elias, Nigerian Land L. appendix (1971).

"'Henshaw v. Henshaw and Org. and Compagnie Francaise, 8 N.L.R. (1927);
Chief Young Dede v. African Association Ltd. 1 N.L.R. 130 (1910).

10'B.O. Nwabueze, Nigerian Land L. (1972).

10BAttorney General of Southern Nigeria v. John Holt, 2 N.L.R. 1 (1910).

294

Fischman and St. Amand

would constitute an interference with these communal uses, or whether such
restrictions would require compensation as existing coastal wetlands migrate.

Swamps and marshes in Nigeria are generally considered unoccupied land that
may be claimed by the government for public purposes. However, in Amodu Mani
v. Secretary of Southern Nigeria, 4 N.L.R. 18 (1923), the government wished to
assert ownership of palm and mangrove swamps and grasslands; the local community
asserted a claim to the land. The court held that the government had to
compensate the local inhabitants, who made significant use of the land for
cultivation, livestock grazing, and industrial purposes. Substantial ongoing
beneficial use of the land was the determinant factor.

Finally, the Water Sources (Control) Law authorizes the government to
declare any river, stream, lake, or navigable waterway a "prescribed source of
water," with which no one can interfere, unless granted prior approval.""
Estuarine wetlands presumably could be declared "prescribed sources" and allowed
to migrate as sea level dictates.

Spain

Coastal wetlands in Spain are regulated primarily pursuant to the Coastal
Law and the 1985 Water Law. The area seaward of the high-water mark (the
foreshore)--including coastal wetlands--is public domain in Spain.'08 In
addition, Spain maintains a 100-meter "police" zone along the coast, where a
license is required to alter the terrain's natural relief, to engage in
construction, or to in any way obstruct the water's floodpath."' It would appear
relatively easy, therefore, to prohibit the construction of seawalls and jetties
along the coast.

For wetlands that fall inland of the foreshore, the water contained in
wetlands is considered to be public domain, although the bed and other natural
resources contained in the wetlands, such as flora and fauna, may be privately
held."' However, all activity in wetlands is subject to government authorization
or concession."' Regulations adopted pursuant to the Water Law also provide
that, in determining the boundaries of a wetland, a natural buffer area may be
112
delimited around the wetland. Government permission is also required for

107M G. Yakuba, Land L. Nigeria 179 (1985).

'O'Spanish Constitution.

"'Cano at 12.

"OLey de Costas, art 2a.

"'Id.

112 Reglamento of 1986, art. 275.2.

295

Legal and Institutional Implications

activities conducted within this buffer area."' This buffer-area regulation
could be used to conserve areas for wetland migration.

While the Spanish Constitution provides for compensation upon
expropriation, 114 the imposition of land use restrictions generally does not
require the payment of compensation to affected landowners.

CLOSING REMARKS

With the inundation of existing coastal wetlands as sea levels rise,
governments are faced with the problem of allowing wetlands to migrate, while
avoiding the financial strain of compensating affected landowners. In the
United States, a restriction on the development of uplands would have to advance
a legitimate state interest and preserve some reasonable economic use of the
property to avoid being classified a compensable taking. While it would be
relatively easy to find that such restrictions advance the public's health,
safety, and welfare, preserving some economic use of inundated property may
require creative legislative approaches, such as the creation of transferrable
development rights. Disputes over the extension of the public trust doctrine
to cover potential new coastal wetland sites may provide the impetus for the
resolution of the takings issues. The most legally feasible policy option for
preserving coastal wetlands is to exact a covenant not to build a bulkhead from
any landowner seeking to develop fastland property in the coastal zone.

Other nations generally do not face the issue of compensation when
implementing restriction on land use. Government prohibitions against building
bulkheads or otherwise restricting the path of wetland migration would,
therefore, be easier to introduce from a fiscal perspective. The political
feasibility of such restrictions both in the United States and in other nations,
however, depends in large part on the value placed on diffuse coastal wetland
benefits.

113 See Ley de Aguas, August 29, 1985, ch. V, art. 103.
"'Spanish Constitution, art. 33.3.

296

STATE AND LOCAL INSTITUTIONAL RESPONSE
TO SEA LEVEL RISE: AN EVALUATION OF
CURRENT POLICIES AND PROBLEMS

PAUL KLARIN AND MARC HERSHMAN
University of Washington
Institute for Marine Studies, HF-05
3707 Brooklyn Ave. N.E.
Seattle, Washington 98195

INTRODUCTION

Nearly 65% of the population in marine coastal states, or 102.5 million
people, now live within 50 miles of the coast (Edwards, 1989). Coastal
communities are being challenged to accommodate this expanding demand by
providing the necessary space, facilities, and infrastructure to support the
swelling population. Sea level rise further complicates and exacerbates the
process of planning in coastal communities.

A rise in sea level within the predicted ranges of 50-368 cm by the year
2100 would subject coastal communities to inundation, increased frequency and
severity of storms and wave surge, increased rates of shoreline erosion, wetland
inundation and recession, modification of dynamic coastal physical properties,
and damage to or reduction in shoreline protective structures and facilities
(Davidson, 1988). Some coastal areas have been experiencing a relative rise in
sea level due to subsidence, reduced sedimentation, and chronic erosion, and are
already actively pursuing policies to ameliorate their effects. The resulting
social and economic impacts on coastal communities from an accelerated rise in
sea level would be unquestionably dramatic and severe.

How state and 'local institutions respond to sea level rise is very
important, since it is at this level of society where the initial impacts will
be felt and where efforts to mitigate them will occur. As pressure from the
public, the media, and political interests increases, coastal resource managers
and planners may be forced to consider actions to mitigate future sea level rise
impacts before questions arising from scientific uncertainty are resolved.

This study is not concerned with the accuracy of sea level rise predictions.
Rather, it examines how policy makers and institutions have begun to address the

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issue. This essay begins with a brief description of the institutional framework
and decision-making processes of the coastal zone management systems. it
summarizes the activities and policies that have been initiated by state coastal
zone management programs in response to sea level rise. Responses are
categorized according to the development of sea level rise as an issue, from its
initial identification as a problem through the implementation of a policy
addressing it. A table showing the level of activities of 24 marine state
coast'al zone management programs is included. A series of case studies provides
an exami nati on of the responses of sel ected state programs i n more detai 1 . The
observations section examines the shared problems and tendencies of state coastal
zone management programs (CZMPs) as they attempt to address the issue of sea
level rise. The study concludes with a discussion of policy trends and what they
might suggest for future action.

COASTAL ZONE MANAGEMENT SYSTEMS

Coastal zone management is broadly interpreted to mean any type of public
activity, intervention, or interest that is applied to the coastal and marine
environment and its resources. Management style, either separate for individual
resources or comprehensive over a wide range of activities and resources, varies
widely. The comprehensive management systems attempt to integrate policy and
planning into a balanced program that addresses the multiple uses, environmental
uniqueness, and economic potential of the coastal zone. Generally speaking,
integrated coastal zone management is embodied in an ongoing government program
charged with resolving the conflicts that arise between the various users and
interests inherent to the coastal environment (Sorensen et al., 1984).

The United States was the first nation to fully develop such a program on
a national scale (U.S.C., 1972). The Federal Coastal Zone Management Act
addresses a broad range of issues: protection of environmental resources,
managing development to minimize loss from flooding, setting priorities for
water-dependent uses, providing public access, redevelopment of urban
waterfronts, the simplification of management procedures, and enhanced public
participation in decisionmaking. The act provides money for state programs
through section 306 grants, which are intended for program administration,
technical studies, local grants, etc.

The act envisions collaborative planning among federal, state, and local
authorities. It is intended to instill a broader "national" interest into the
process of coastal land use planning -- a responsibility that has traditionally
resided with local governments. As conceived in the act, coastal zone management
is a state responsibility. However, implementation is often delegated to local
governments, with the implicit assumption that local authorities accept the
state's role as their partner in regulating land use in the coastal zone (Brower
and Carol, 1984). Federal activities must be conducted in a manner that is
consistent with the federally approved state programs -- a provision that
requires collaboration with federal agencies.

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Other federal laws require the involvement of numerous federal agencies and
departments in coastal zone decisionmaking. The National Environmental Policy
Act requires all federal agencies to consider the environmental effects of their
decisions. The Clean Water Act involves the Environmental Protection Agency
(EPA) through such programs as its Office of Marine and Estuarine Protection.
The Army Corps of Engineers has the longest and most direct involvement in
coastal development through the authority vested in the Corps by the Rivers and
Harbors Appropriations Act of 1899. The National Flood Insurance Program brings
the Federal Emergency Management Agency into the process through coastal
floodplain management. The Upton-Jones Act created a voluntary program that
provided monetary incentives for property owners to remove damaged structures
or relocate threatened structures in hazardous flood areas. The Coastal Barriers
Resources Act of 1982 creates a national system of coastal barrier areas within
which the federal government prohibits federal subsidies for infrastructure and
hazard insurance; in addition, it requires congressional action to include new
areas within the system.

The management of hazards in the coastal zone is a major feature of coastal
zone management programs. The hazards include inundation and storm damage to
private property and public infrastructure and longer-term risks from erosion,
bluff destabilization, and saltwater intrusion. Coastal hazards can
significantly alter critical coastal environments and eliminate recreation and
transportation resources. In this sense, the hazards issue raises many other
issues important to coastal zone management, such as protecting coastal habitat,
preserving access to shorelines, and ensuring coastal development. Because sea
level rise will exacerbate all other coastal problems, it becomes an issue that
is central to the concerns and objectives of coastal zone management. Developing
strategies that fulfill the basic goals of coastal zone management while
addressing the potential threat from sea level rise will require policies that
are politically feasible, conditionally flexible, and strategically forward
looking. How the system responds will determine the future of our coastal
communities.

RESPONSE CRITERIA AND RANGE OF POLICY INITIATIVES

Table I classifies how state CZMPs have responded to the concerns about sea
level rise. CZMP responses fall into four stages: (1) official recognition
and assessment of problems and issues; (2) new public and intergovernmental
processes; (3) existing adaptable regulation; and (4) new policies responding
to sea level rise. The four steps in the process evolve from formal recognition
to direct policy response. The separation between categories is not always
clearly evident, and it requires some subjective judgments on the authors' part.
Nevertheless, it provides a method for organizing a broad and dissimilar range
of activities into a form that is more easily accessible and from which an
analysis may be drawn.

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Table 1. State CZMP Responses to Seal Level Rise

Official recognition
and assessment of New public and Existing New policies
problems and issues intergovern- adaptable responding to
by CZMP mental processes regulation sea level rise

Alabama No No Partial No
Alaska No No No No
California Yes No No No
(SFBCDC)' Yes Yes NA Yes
Connecticut No No No No
Delaware Yes Yes Partial No
Florida Yes Yes Partial No
Georgia No No No No
Hawaii Yes No No No
Louisiana Yes Yes No No
Maine Yes Yes NA Yes
Maryland' Yes Yes Partial No
Massachusetts Yes Yes No No
Mississippi No No No No
New Hampshire Yes No No No
New Jersey Yes Yes Partial No
New York Yes Yes Partial No
North Carolina Yes Yes Yes No
Oregon Yes Yes No No
Pennsylvania' Yes No No No
Rhode Island Yes Yes Partial No
South Carolina Yes Yes NA Yes
Texas No No Partial No
Virginia' Yes No No No
Washington Yes Yes No No

NA: Denotes that the state Coastal Zone Management Program officially considered sea level rise
in its policy.
Partial: Denotes existing adaptable policies provide partial restrictions on coastal
development.
a Regional authority having limited jurisdiction within California.
b Response as coastal state and as participant in Chesapeake Bay Agreement.
C State's activities limited to participation in the Chesapeake Bay Agreement.
Puerto Rico, Virgin Islands, N. Marianas, American Samoa, and Guam are not included.

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Official Recognition and Assessment of Problems and Issues

This category consists of any activity by the state or local CZMP that
involves the formal recognition of sea level rise as an environmental condition
with implications for that region. Documentation may take the form of any
departmental report, memo, newsletter, executive proclamation, legislative
finding, or other official statement to the effect that sea level rise is a
contributing factor to coastal hazards and erosion. Though program managers and
planners may be personally familiar with the issue, problem recognition as it
is being used here requires that sea level rise be referred to in an official
document describing its climate origins and potential impacts.

Six states have not officially recognized sea level rise as a problem worthy
of attention: Alabama, Alaska, Connecticut, Georgia, Texas, and Mississippi.
Of these, Mississippi is in the initial stages of planning a sea level rise
workshop in the coming year (Mitchell, 1989). Connecticut has not taken any
official steps. However, in 1987 the Town of Fairfield held a two-day symposium
on sea level rise attended by state and federal officials, some of whom made
presentations (Bienkowski, 1989). The reasons given for this lack of official
recognition or response include concern for more immediate and urgent matters,
limited resources and staff expertise, the belief that current policies are
adequate for addressing the problem, and political constraints inhibiting the
coastal zone management program's ability to effectively attend to all of its
responsibilities (Hightower, 1989; Marland, 1989; Miller and Leatherman, 1989).

There appears to be no correlation between the threat sea level poses for
a particular state and its response. Nor has a common institutional feature been
found in the states that have not yet recognized sea level rise. Some states
that have yet to actively respond, such as Georgia and Connecticut, could face
significant problems in the event of sea level rise. Several states with less
exposure to damage, inundation, and loss of property -- such as Oregon and New
Hampshire -- have already initiated studies of the implications of sea level rise
for their coastlines.

Eighteen coastal states have recognized sea level rise as an event with
implications for their coastal areas. In most cases, the state CZMP makes the
initial recognition and subsequently guides the process of researching and
assessing the impacts that sea level rise may have for the state or region. The
California Coastal Commission report, "Planning for an Accelerated Sea Level Rise
Along the California Coast," issued in 1989, is typical of the initial efforts
seen in many states. It contains an overview of the scientific theories and
findings concerning climate change and sea level rise, the range of possible
impacts on the state's coastal resources and environment, a review of available
policy options, and an assessment of further research needs. These initial
studies and reports consistently point out the uncertain nature of the problem
and often avoid analyzing the alternative policy choices -- in some cases
skipping over them completely. Hawaii, one of the first states to address a sea
level rise, has yet to develop specific policy recommendations as called for by
the state's CZMP report and the Senate resolution that ordered it in 1984.

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New Public and Intergovernmental Processes

This category refers to the systematic process of agenda setting and policy
formulation. This includes efforts to build a consensus through a task force,
legislative hearings, or a series of public workshops. Efforts to inform local
governments and affected citizens are instrumental in the process and are
designed to integrate the views and considerations of the public and other
interests into the formulation of a policy response.

At this stage, the issue has progressed to the point of being recognized
as both salient and legitimately of government concern. It is formally addressed
by a wide range of decisionmakers who must take an active part in considering
what, if any, type of policy should result. Also, the participation of both the
public and private sectors and the types of forums within which the issues will
be contested are established at this stage. Who gets involved and to what extent
they participate in the formulation of policy determines who will have the
authority and how that policy will eventually be implemented. There is evidence
of new agenda-setting processes in 14 coastal states.

In New York, the Long Island Regional Planning Board has recognized sea
level rise as a causal factor in flooding and erosion in its South Shore Hazard
Management Program. Mandated by the New York State Department of State to
prepare a comprehensive program addressing chronic erosion and severe storm
events, the board is trying to develop strategies and policies that would
integrate the federal, state, and local interests into a coordinated response.
Its goal is to focus on long-term (i.e., 30- to 50-year) planning strategies
based on land use planning policies and taking into account the local geomorphic
conditions (N.Y.D.S. 1988). The board has outlined a preferred management plan
based on strategic retreat, selective fortification, and conditions for new
development. It has inaugurated a series of workshops, in conjunction with the
state Sea Grant Program, involving coastal engineers and researchers and focusing
on technical and scientific topics. The New York/New England Coastal Zone Task
Force sponsored a study evaluating the long-term economic impacts of various
options for controlling chronic erosion, which was to be used as a model for
evaluating policy alternatives. That study, "Developing Policies To Improve the
Effectiveness of Coastal Floodplain Management," compared the costs and revenues
associated with various responses under different sea level rise scenarios.

In Oregon, the issue of sea level rise is one of many being addressed by
the state's Task Force on Global Warming. The state's Department of Energy has
prepared a report, "Possible Impacts on Oregon from Global Warming." The report
examines the impacts of sea level on selected Oregon coastal communities, but
makes no reference to policy strategies or responses, except to say that the
price of protection may be too high. Oregon's Department of Land Conservation
and Development is the agency through which the CZMP is implemented, and it has
not issued any official report of its own on the issue.

The State of Washington's Shorelands Division of the Department of Ecology
has formed a sea level rise task force. The task force has initiated a number
of technical studies and a policy alternatives study in an attempt to establish

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a comprehensive understanding of the issue. One of the primary features of the
Washington task force is the effort to involve other state agencies, local and
regional governments, environmental groups, and private commercial interests into
the process of establishing the policy agenda (Canning, 1989).

Similarly, Delaware is establishing a new comprehensive beach management
policy based upon the recommendations of the Beaches 2000 planning group and
citizens' advisory committees. The recommended plan would be a strategic retreat
policy consisting of beach renourishment programs, setbacks based on historical
erosion rates, postflooding redevelopment restrictions, and public land
acquisition programs.

Existing Adaptable Regulations

This category includes statutes, codes, or rules that are designed to be
effective regulatory instruments within a range of environmental conditions.
They may be regulations that are intended to cope with conditions like those that
would result from sea level rise. Examples are a setback requirement established
according to a physical feature, such as tideline, that is periodically
recalculated, or a law that prohibits redevelopment of a hazard-prone area.
While not specifying sea level rise as the causal factor, the practical
application of such flexible regulatory instruments would effectively limit
development in response to changing environmental conditions.

There are many instances where existing policies may be responsive to sea
level rise. Seven coastal states have setbacks that are based on an average
annual recession rate derived from a multiplier of the annual erosion rate. Of
these, North Carolina could be characterized as having the most progressive and
adaptable setbacks, since it has the most thoroughly defined baseline for
measuring setbacks that are adjusted periodically to account for changes in the
shoreline. It also restricts the size of the structure based on its distance
from the baseline (N.C. CAMA, 1989). Setbacks calculated on erosion rates are
designed to recognize the ongoing erosion of the shoreline; thus, they would be
responsive to changes in sea level. The Rhode Island Coastal Resources
Management Program lists historic sea level rise as one of the contributing
factors for erosion in its Shoreline Features section. The state has variable
setbacks equal to 50 feet or the erosion expected in 30 years (assuming current
trends), whichever is greater. It uses various physical features of the
shoreline, such as dune crests and vegetation lines, as the baseline from which
the setback is measured.

The construction control line in Florida demarcates an area bordering the
shoreline within which certain building standards and permits are required. The
line is periodically recalculated for each county to account for changes in the
shoreline. In some states, a static setback control line is established. These
setbacks do not reflect dynamic changes in the shoreline. For example, in
Hawaii, where the setback is 40 feet from the highest wash of the waves, the line
of protection can easily be erased by severe storms (Noda, 1989).

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The Texas Open Beaches Act, which will be discussed in the case studies,
states that any property seaward of the vegetation line is open to public access.
Many property owners have found their homes on the wrong side of the line after
a storm, and are prohibited from repairing or rebuilding their damaged structures
(Martin, 1989). While the law forces the eventual abandonment of developed
property in the eroding beach areas, it does not prevent new development from
being placed in equally hazardous circumstances.

New Policies Responding to Sea Level Rise

New policies can be in the form of a legislative act, regulatory rule, or
administrative decision wherein sea level rise is identified as a causal
component of the problem being addressed. It provides a regulatory instrument
for integrating potential sea level rise considerations into coastal management
and planning decisions. Though it may be incorporated into a regulatory response
to chronic beach erosion, wetland destruction, or increased flooding, sea level
rise is specifically identified as a contributing factor to that problem. The
resulting regulatory instrument is designed to effectively adapt to the changes
in the environment brought about as a result of sea level rise.

Three states (South Carolina, Maine, and Rhode Island) and the San Francisco
Bay Conservation and Development Commission have designed new policies that
respond directly to sea level rise. In each case, the policy and the way it came
about have similarities and differences. They are all the result of concerted
efforts on the part of CZMP and other related professional agency staffs, who
introduced the initial technical research information and initiated the process
of public debate and political machinations. However, the types of policy
outcomes that resulted are dissimilar.

South Carolina, which will be discussed in the case studies, has established
setbacks based on current erosion rates very similar to those of.North Carolina.
The difference in categorization is that South Carolina stipulated the role of
accelerated sea level rise in the new statutes. Maine, under its Sand Dune Law,
has restrictions on the size and density of new development in hazardous areas
and limits the construction of structural protection devices like seawalls and
revetments (Dickson, 1989). It also restricted permits for extracting water from
the coastal aquifers in order to protect them from saltwater intrusion. The San
Francisco Commission amended its Bay Plan to establish a new permit requirement
for development. Future structures will have to meet engineering standards that
could withstand increased water levels. The Commission did not establish any
fixed estimate of sea level rise and each project is evaluated on an individual
basis by a technical engineering review board (BCDC, 1989).

CASE STUDIES

The need to explore and examine the response of coastal zone management
systems to the issue of sea level rise becomes more significant as public
officials and private interests begin to struggle with its implications. In the
early stages of policy development@ this is best done through a series of case

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studies. As events progress, it is necessary to take an inductive measure of
the process that is driving new policy-making activities. An examination of a
broad range of experiences provides a more comprehensive understanding of the
context within which issues are being addressed and policies are being formed.

The case studies that follow were chosen to illustrate the variety of ways
in which state CZMPs have responded to sea level rise. The first case, South
Carolina, is an example of a program that has new policies controlling
development and land use practices in response to sea level rise. That is
followed by Florida, which is in a transitional phase of policy development.
Texas, on the other hand, has not begun to address the problem of sea level rise
and has no,mechanisms in place that are capable of doing so comprehensively.

South Carolina'

In South Carolina, the issue of sea level rise has been entwined with the
chronic coastal erosion problems that have plagued that region for decades.
Coastal flooding and inundation problems caused by natural processes, in this
case the geomorphic transformation of the barrier islands and subsidence, are
being exacerbated by rapid development. In 1984, Charleston was the site for
an EPA study about the impacts of sea level rise. Numerous other studies were
conducted over the next few years, all of which confirmed in ever greater detail
the risk that was posed by sea level rise for coastal communities in that state.
A symposium on sea level rise that same year brought forth strong opposition from
local interests concerned with the negative impacts that any action might have
on development and property investments.

The issue became one of the focal points for the South Carolina Blue Ribbon
Committee on Beachfront Management, which was formed in October 1986 to
investigate the problems of beach erosion and to propose long-term solutions.
The committee consisted entirely of representatives from coastal county and
municipal governments. A major storm on New Year's Day of 1987, which destroyed
numerous structures and vastly accelerated the erosion process, increased public
awareness and ameliorated the political conditions for new coastal development
policies.

The coastal zone program in the state is administered by the South Carolina
Coastal Council under the Coastal Tidelands and Wetlands Act of 1977. One of
the committee's findings was that the Council was unable to effectively implement
the legislation because it was not given sufficient authority over development
in the beach and dune areas. Consequently, property owners were building
structures in erosion-prone beach areas susceptible to storms and flooding and

'References include: South Carolina Blue Ribbon Committee on Beach
Management; South Carolina Beach Management Act 1988; Future Sea Level Rise and
Its Implications for Charleston, South Carolina; The Physical Impact of Sea Level
Rise in the Area of Charleston, South Carolina; Local Responses to Sea Level
Rise, Charleston, South Carolina; and Coastal Zone Management Newsletter.

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were able to obtain permits to build protecti 've devices as well. In addition,
they were allowed to rebuild houses and structures damaged in coastal storms.

The committee's findings stated that the state's coastline was in crisis
66tause of erosion and that sea level rise was the primary cause. It further
csalled for the legislature to amend the coastal councils' enabling legislation
to give it the authority it needs to provide effective stewardship of the coastal
resources. The committee's findings became the impetus for a legislative bill
that sought to institute a retreat policy while limiting,the construction of
Ootective devices. The bill, which amended the originating statute, was opposed
by.property owners, developers, and lending institutions who felt that property
values and opportunities would be adversely affected.
Though the eventual bill, known as the Beach Manag6ment Act of 1988, was
slightly diluted and required considerable debate before passage, it did achieve
much of what was sought. Effective as of July 1, 1988, setback lines were
established at 40 times the annual erosion rate for residential buildings. The
b,aieline for the setback, the crest of the ideal sand dune, was to be determined
uiing current monitoring and scientific analysis by coastal geologists and
engineers. It would be reset within 10 years and between every 5 to 10 years
following. The act calls for a 40-year planning horizon. Within the next 30-
year period, all vertical seawalls would have to be replaced with an approved
Protection device, and those that had been more than 50% damaged must be removed
The bill also requires that property owners renourish beach sand at a rate oi
oh@ and half times the yearly volume lost to erosion whenever an erosion device
is; damaged or destroyed. This requirement promises to become increasingly
cumbersome and costly.

The Beach Management Act also stipulates that local governments create their
own beachfront management plans. These plans must be consistent with the South
Carolina Coastal Council's long-range comprehensive beach management plan, which
the act requires to be developed by 1990. Any local government failing to
establish a plan would be subject to the planning guidelines established by the
Council. If a local government failed to enforce the beach management plan, it
would lose its eligibility to receive state money forbeach or dune projects.

The experience in South Carolina illustrates the successful linkage of sea
level rise with ongoing and significant issues., It also represents the
persuasive impact of research and information on decisio *nmakers and the public.
The role of the Blue Ribbon Committee in advancing the issue on the political
agenda reflects the necessity of incorporating the perspectives of local
decisionmakers in the formulation of policy. The advocacy of state regulatory
agencies, the research and academic community, and key local decisionmakers on
behalf of the new regulatory regime resulted in its passage.

Nevertheless, the state's actions remain controversial among property owners
and, though it has been sued at least five times for the "taking" of property
rights, it continues to adhere to a strong retreat policy. The Council's "Dead
Zone" policy, which restricts the building or rebuilding of structures damaged
by;' 'storms in an area deemed as highly hazardous, has been successfully challenged

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in a lower court, with one property owner winning $1.2 million. The policy,
which states that structures that are more than two-thirds destroyed may not be
rebuilt, will affect approximately 159 of the 700-900 buildings damaged by
Hurricane Hugo. The Flood Insurance Administration estimates it will be paying
$300-$400 million in claims as a result of Hugo, with most of that coming from
South Carolina.

It remains to be seen whether the catastrophic impacts of Hurricane Hugo
will foster a more stringent attitude toward coastal development. Experience
has shown that such events do provide the impetus for more restrictive coastal
development policies. The reconstruction and continued development of the
barrier islands in the next few years will test the seriousness of South
Carolina's resolve to enforce its retreat policy.

Florida2

Florida's Coastal Management Program originated in 1981 following the
state's Coastal Management Act of 1978. The program is based on 27 state laws
administered through 16 state agencies, with the Department of Environmental
Regulation as the lead agency in which the Office of Coastal Management is
housed. The Departments of Natural Resources and Community Affairs are alto,
involved in implementing the CZMP. An Interagency Management Committee',
consisting of the heads of the agencies with major roles, acts as a board of
directors in formulating policy and ironing out interagency jurisdictional
issues. The Interagency Advisory Committee consists of staff from various
agencies who undertake specific tasks and make recommendations to their
departments about the program. The Coastal Resources Citizen's Advisory
Committee provides an opportunity for public input and review of the CZMP. The
committee's members are drawn from government, environmental, and other interest
groups, and private citizens appointed by the governor to two-year terms.

Sea level rise poses a substantial threat to Florida, where 70% of the
population resides along the coast, and which has been experiencing a relative
rise of 8 to 16 inches per 100 years since 1932. Many areas would be inundated,
and tens of thousands of people displaced. Major infrastructure, such as coastal
power generators, roads and bridges, drainage systems, and flood protection
structures, would be affected. Saltwater intrusion into coastal aquifers could
create water resource problems, and a higher water table would exacerbate
flooding. Shifts in marine ecosystems could alter the distribution of fisheries

2References include: Florida Beach and Shore Preservation Act, 1987;
Florida Coastal Resources Management Citizens Advisory Committee Annual Report
1989; Department of Environmental Regulation memo on Coastal Resource;
Interagency Advisory Committee Sea Level Rise Subcommittee; The Inundation of
South Florida: Past, Present, and Future; Impact of Climate Change on Coastal
Resources: Implications for Property Values, Commerce, Estuarine Environments,
and Fisheries, with Special Reference to South Florida; Cosper, C., personal
communication.

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and increase nuisance marine organisms. Precious mangrove habitats and coral
reefs may suffer deterioration.

Sea level rise has become a component of the large debate that concerns
increasingly dense coastal development and the implications that development has
for storm-induced damage and coastal flooding, erosion control, beach
preservation, water resources, subsidence, and a number of other environmental
and social factors. Though the state CZMP and some members of the Interagency
Advisory Committee and Citizen's Advisory Committee made a concerted effort to
have the issue of sea level rise ratified as an issue of special focus for the
Interagency Management Committee, it was not accepted. In the Management
Committee's opinion, responding to sea level rise is a federal problem, and if
the federal government has made no declaration or directive concerning it,
Florida has no cause to act. The conventional wisdom of the Management Committee
was that the state has only two choices -- build a wall or move the buildings
-- and that no policy existed to do either. It was pointed out by the CZMP staff
at that time that, although no policy existed, the wall had already been
constructed in the form of dense development and the protective devices
associated with it. Furthermore, the state has made it a policy to preserve the
beaches fronting the developed areas through beach renourishment programs.

Florida first implemented its Coastal Construction Control Lines in 1970
and strengthened them in the Beach and Shore Preservation Act of 1987. The
control lines cover a 100- to 1,000-foot band along 795 miles of sandy beaches
and dune areas subject to the 100-year storm surge. Implemented on a county-
by-county basis and requiring a public hearing to be held by the Governor and
Cabinet, the control lines are intended to mitigate further beach erosion and
to protect upland properties. New structures within the area designated by the
control lines must meet building codes designed to withstand a 100-year storm
and flood tide. Control lines are set according to current data establishing
a 30-year erosion zone. The data are based upon a comprehensive engineering
study and topographic survey that considers the historic storm and hurricane
tides, wave surge, beach and offshore contours, erosion trends, the dune or
bluffline, and existing development. Counties are allowed to establish zoning
and building codes in lieu of the control lines, provided they are found adequate
by the Department of Natural Resources to serve the same function.

Simultaneously, the legislature created the Beach Management Fund and
allocated at least $35 million for the Department to use annually toward erosion
control, hurricane protection, beach preservation, restoration, and
renourishment. In fiscal year 1988-89, the state legislature approved $13.3
million for beach renourishment projects, which, when added to federal matching
funds, amounted to almost $30 million. These funds finance the renourishment
projects that serve as the state's primary method of erosion control and
shoreland preservation. The local government is required to fund 25% of the cost
for any projects deemed necessary by the Department of Natural Resources. The
state also uses the fund to pay for its share of federally approved erosion
control renourishment projects. Florida has also implemented a public lands
acquisition program over the past decade, buying beach property for public
recreational uses and resource protection.

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The recent onslaught of Hurricane Hugo has posed some questions and
opportunities for Florida. An increase in the number and severity of tropical
storms has been predicted as a result of climate-change-induced warming of
surface water and sea level rise. The extensive damage seen in South Carolina
may be small compared to the level of damage that would have resulted if the
hurricane had struck South Florida. The state is now beginning to consider
whether its current post-storm reconstruction practices are adequate for the
protection of life and property after such a storm. The implications for areas
such as Florida, with its low beach profile and porous substrate, are serious.
While the control lines have prevented many poorly conceived and designed
development projects from being built, post-storm redevelopment has not been
limited to any degree, and many property owners have used grandfather clauses
to rebuild in areas susceptible to storm damage and flooding.

Currently, the state CZMP, in conjunction with the research community, is
planning to conduct a symposium on sea level rise as part of the statewide
coastal conference in hopes of attracting the participation of technical experts
and planners. They are also submitting a grant request for federal funds under
section 306 of the Coastal Zone Management Act to conduct a study of the regional
impacts of sea level rise on the Tampa Bay area.

Florida faces some hard choices and difficult problems, regardless of
whether sea level rise predictions hold true. The rapid and dense development
of its coastal areas has exacerbated environmental problems and has frustrated
hazard mitigation efforts. Attempts to address those issues naturally clash with
the pressure for more development. Officials within the state's CZMP, public
interest groups, and others who support programs that would provide for more
comprehensive planning and stricter controls on coastal development find it very
difficult to muster the necessary political support. Current policies are
limited to storm-proof building requirements and extensive beach preservation
and renourishment programs. The value of Florida's beaches and shorefront
property make this a predictable outcome. Sea level rise, if it ever is
seriously addressed, will probably "piggyback" onto more immediate and tangible
issues, such as hurricane mitigation and post-storm redevelopment policies.

Texas'

Texas is suffering from chronic erosion along 60% of its 400-mile shoreline,
consisting largely of barrier islands. Decreased sediment supply, subsidence,
and relative sea level rise, compounded by intense storm events, cause some areas
to lose up to 50 feet per year. Despite the considerable risk this may pose to
valuable property, infrastructure, fisheries, and the Gulf Intracoastal Waterway,
the state has been reluctant to invest in coastal projects that may mitigate the
erosion process.

3References for this case study include: Texas Beaches and Dunes
Regulations Chapter 63; Martin and Dearmont in Texas Shores; Texas Shorelines
Newsletter; Hightower, M. and Bright, T., personal communications.

309

Vand Institutional Implications

'Texas has not developed a federally approved CZMP and has no comprehensive
Atte'Wide program addressing coastal -resource protection and development. After
*44.demise of the Texas Coastal and Marine Council in 1985, no institutional
Whanism was left in the state to deal with coastal issues. Attorney General
K"'Cross stated that there is a vacuum in-the state in terms of managing its
ttal resources. Although at least 10 state and federal agencies are involved
W.coastal matters, there is no consistency or lead authority, and local
Communities retain almost total control over land-use planning and development
;*tegies, with very little outside guidance. The response of many local
Ownities faced with erosion problems is to transfer it down the beach by
@"king some hard protective solution that aggravates the problem by reducing
natural sediment movement.
V
In the case of Sargent Beach, a 10-mile strip of shoreline fronting the Gulf
Intracoastal Waterway and resting upon a mud base, the erosion rate exceeds 100
feet.,per year. The Army Corps of Engineers, charged with the responsibility
fw-'the waterway, may require anywhere from 5 to 15 years to study, plan, and
respond to the problem. Meanwhile, there is a possibility that the area may be
1.0'eluded in the Coastal Barriers Resource System and become ineligible for
federal funds for projects that would restore the beach or move the channel.
In recognition of the loss of approximately 12.5 square miles of land during
thd-,past century, the Galveston Bay area was the site of a 1984 EPA-sponsored
OWY, "Coastal Geomorphic Responses to Sea Level Rise: Galveston Bay, Texas,"
Witherman (1984). Estimates from Titus and Greene (1989) project a cost of $83
mill-ion for bulkheads and relocations in Corpus Christi should there be a 7-inch
ri$o in sea level. The cost of renourishing sand on Texas beaches over the next
ohitory, under that scenario, was estimated at $17.6 billion. Numerous other
#Vdies have been conducted focusing on the erosion problems along the Texas
c9sit, but the weight of evidence has not had an impact on coastal development
pr0tices.

Though the state has yet to recognize sea level rise officially, it does
have a law that inadvertently but effectively reduces the redevelopment of
'i
eision-prone beaches. Through the Texas Open Beaches Act of 1959, the public
*Ahe right to use all beach areas seaward of the vegetation line, and no one
"y.,Orect barriers to prevent the public from using them. This act will have
increasing impact as the vegetation line recedes beyond existing development
lt of chronic erosion and severe storms. After Hurricane Alicia struck
resu
11983, the vegetation line retreated from 20 to 145 feet. This prompted over
1661awsuits by property owners against the state, and 15 suits by the state
4inst property owners who were rebuilding. The courts have thus far upheld
th state's position, and legal action by property owners challenging the statute
taking have failed. Assistant Attorney General Ken Cross remarked, "We
didn't create this problem. This is a harsh situation, not because of what we
014`-but because of Mother Nature."

local communities continue to permit coastal development in
i.001 on- and hazard-prone areas. The experience of Texas illustrates the
""I ems that result from a lack of comprehensive planning and sound fundamental
!7
310

Marin and Hershman

objectives in coastal development and land-use practices. The legislation that
is in place acts as a reactive mechanism, creating conflict and further degrading
the public's perception of the state in coastal affairs. Without s1ghificarft4l
changes in the pattern of development along the coast, these problems are likely'l"
to conti nue. Yet there i s 1 i ttl e support for devel opi ng a statewi de program that
could address these problems, and even less for a federally approved CZMP.
Ironically, the most effective policy response affecting Texas may eventuall"y
result from federal efforts to encourage a retreat from areas subject to coastal
erosion and hazards, such As provi'ded by the Upton-Jones amendment to the
National Flood Insurance Program and the restrictions on coastal barrier isl'And:
development established,by the Coastal Barriers Resources Act.

OBSERVATIONS AND CONCLUSIONS

Common Problems

All state and local CZMPs share a common set of problems related to s 6-a
level rise. The most prominent is the issue of property rights. The delicat6.,
balance between private property interests and public policy objectives fs
becoming increasingly difficult for CZMPs to maintain, as conflicts betwe46
development and environmental concerns mount. Changes in coastal development
policies are directly linked to land use planning, and are often percei ,ved by
developers, 'property owners, and lending institutions as a taking of pri ,v.Iate.
property for the general public's benefit for which they should be compensat6d.-
(See Fishman and St. Amand this section, this volume.) Legal chal 1 enges , tu@
policies that require property owners to yield the use of their property are fa
be expected. When the Coastal Barriers Resources Act was being debated '@,iw
Congress, the National Association of Realtors and the National Association"0'
Home Builders charged that the bill discriminated against coastal property own6'e's."
and infringed on their property rights (Dearmont, 1989)'. Policies addressinq@,
the potential impacts of sea level rise that are sensitive to local property anV'
development interests and that are on firm authoritative ground are preferred,
but it is not certain that they are doing the job.

Aside from the uncertainties regarding sea level rise, there is a lack of-
information and data concerning how it may affect particular coastal regions'.
Without comprehensive baseline data for regional coastal ecosystems and
geophysical conditions, it is difficult to reliably monitor geomorphic changes.
Few local governments have the resources to obtain such information, and state'-
CZMPs are not always able to provide the necessary technical assistance. This-
contributes to the problem of local implementation once policies are in place.@. -

Political constraints are another prominent factor. In light of the
inherent uncertainties of climate change and the lack of regional impact data,*,
policy- makers are reticent to support controversial initiatives without'@.
substantial evidence that those policies are necessary and in the publilc
interest. While CZMPs strain to promote long-term planning policies, many state
and local officials and private interests are influenced by a different set of

311

Legal and Institutional Implications

dynamics: short-term economic objectives, electoral cycles, and a reluctance
to surrender control over the local planning process.

Common Activities

A number of factors are common to many CZMPs responding to sea level rise.
One is that the issue is usually internally generated by key professional staff
within the CZMP network. Often staff members are responding to peer pressure,
as concern about climate change has raised the concern about sea level rise among
coastal officials, researchers, and the public throughout the nation and the
world. Key staff people become policy entrepreneurs, actively promoting the
issue and establishing a network among other agencies, technical experts, and
local governments.

Section 306 grants under the Coastal Zone Management Act are the primary
source for funding the initial technical studies and program activities related
to sea level rise. Under a section 306 grant, up to 30% of the grant must be
spent on projects that result in "significant" program improvement, rather than
ongoing program implementation. Funding for followup studies and research must
be sought from state sources or through federal agencies, like EPA or the Federal
Emergency Management Agency, to conduct research studies related to their
particular areas of concern. The availability of funding for'baseline data
research and monitoring is critical to the success of CZMP efforts to develop
policy responses to sea level rise.

Typically, sea level rise is linked to existing programs and objectives.
Policies that are based on pre-existing authority are more politically acceptable
and easier to implement. The uncertainty of sea level rise is offset by its
association with a significant existing problem. The focus of attention is
transferred to existing long-term objectives and goals. Be it wetlands, beach
or dune preservation, or protection from storm flooding, linkage provides
credibility and alleviates some of the uncertainty by making sea level rise more
of a present-day issue. Those issue areas benefit because sea level rise
heightens concerns about achieving existing program goals. The states that have
integrated sea level rise into their policies have done so on the basis of pre-
existing program goals.

Policy Trends

Strategic or adaptive retreat policies are becoming the preferred response
to sea level rise among state CZMPs. Typically, strategic retreat encompasses
a range of regulatory activities and programs in the form of a comprehensive
management and planning program. There are a number of features common to
strategic retreat policies, the most prominent being laws or regulations that
allow the conditional use of property located in areas susceptible to erosion
and flooding, restrictions on hard structural protection, protection of critical
environmental areas, and post-storm redevelopment restrictions. Strategic
retreat policies also recognize that densely developed areas will require some
form of structural protection, while the dynamic geologic processes should not
be impeded-in less developed and undeveloped coastal areas.

312

Klarin and Hershman

The use of setbacks based on historical erosion rates, like those in South
Carolina, and restrictions on coastal development size and density as found in
Maine, are attempts to provide an opportunity for property development in a
manner consistent with the long-term goals of the CZMP. Allowing the conditional
use of the property avoids some legal challenges and reduces the opposition of
property owners. Implementing such regulations requires a mapping program to
establish a baseline and a periodic monitoring program to track the geomorphic
changes in the coastline. As the relative sea level changes, the setbacks can
be adjusted accordingly.

The use of hard structural protective devices is increasingly restricted,
especially in areas considered to be critical environmental resources like sandy
beaches, dunes, and wetlands. Many states require property owners to use non-
intrusive protective measures, such as planting grasses or building artificial
dune barriers, rather than seawalls and revetments. In many states, critical
environmental resources are areas that receive special protection in the form
of buffer zones and building restrictions. Ecosystem restoration programs using
"soft" engineering strategies, such as revegetation, are becoming more prevalent.
Conservancy land acquisition programs, both public and private, are another
innovative way of preserving critical habitats and environments.

Post-storm redevelopment policies that require structures to be moved or
abandoned if they receive substantial flood damage and are susceptible to
continued flooding are also instrumental in forcing a retreat. Another means
is to transfer the real cost of owning coastal property to the owner by removing
the subsidy provided by federal flood insurance coverage for structures in
hazardous locations. Requiring property owners situated in hazardous areas to
bear the part of the cost for improvements to the infrastructure that serves them
is another way of transferring the cost to the property owners. The use of tax
incentives and disincentives to promote the preservation of undeveloped property
is another vehicle for controlling land use, as are incentives to locate or
relocate structures in preferred areas and disincentives for placing them in
hazardous areas.

Renourishment programs are an important component of strategic retreat
policies because they help preserve the status quo by selectively maintaining
the beachfront. Programs like those in Florida, designed to preserve the beach
as a method of hazard mitigation, also distribute the costs over a wider base.
Renourishment programs are a trade-off as long as they are economically feasible.
Like other soft engineering strategies, renourishment provides an environmentally
acceptable method of preserving beachfront for areas that are simply too valuable
not to protect.

The federal government has provided some support for states seeking to
initiate retreat policies by implementing similar strategies within areas where
they have authority. The Upton-Jones Act is a voluntary program under the
National Flood Insurance Program that seeks to change redevelopment practices
by providing direct monetary incentives not to rebuild, but to tear down or move
structures in highly hazardous coastal flood zones. It received only moderate
acceptance during the first two years of the program, with nearly half of the

313

Legal and Institutional Implications
I@,9 claims coming from the state of North Carolina (Buckley, 1989). The Coastal
garrfers Resources Act eliminated federal expenditure's for flood and disaster
insurance and restricted public expenditures for infrastructure on designated
un'developed barrier islands. It requires congressional action to expand the
barrier system, and local officials and congressional representatives often
resist federal expansion into state jurisdiction.

Sea level rise poses both a problem and an opportunity for state CZMPs.
State coastal zone management programs normally do not have the authority or the
9
olitical leverage to directly control local land use and planning. They are
,ependent on a partnership with other federal and state authorities, local
AdvOrnments, and private interests. CZMPs must continue to work toward the
multiple and sometimes contradictory objectives of the Coastal Zone Management
Act. Yet, they are the one institution capable of addressing the issue of sea
Mvel rise comprehensively and systematically. Linking sea level rise to more
immediate and tangible issues provides an opportunity for CZMPs to increase their
role in coastal land use policy. Programs that are able to incorporate sea
16vel rise -considerations into their overall program, objectives will succeed in
@@q.aiden:ing the scope and range of the planning process.

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Brower, D.J., and D.S. Carol. 1984. Coastal Zone Management as Land Planningd;
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Buckley, M. 1989. FEMA Office of Risk Assessment NFIP. Personal communicatioot@
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Canning, D.J. 1989. Washington Shorelands and CZM Program. Personal
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Canning, D.J. 1989. Sea Level Rise in Washington State: Technical Issues Ad
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Davies, D. 1989. Long Island Regional Planning Commission. Personal
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Dearmont, L. 1988. Bureaucratic barriers. Texas Shores 21(2):16-28.

315

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Delaware. Amendments to the Beach Preservation Act of 1972. Regulations
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Delaware Dept. of Natural Resources and Environmental Protection, New Jersey
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Delaware Environmental Legacy Program. 1988. Beaches 2000. Report to the
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Dickson, S.M. 1987. Coastal hazard mapping in Maine. Geological Society of
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Edwards, S.F. 1989. Estimates in future demographic changes in the coastal
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Everts, C.H. 1988. Effect of Sea Level Rise and Net Sand Volume Change on
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Beach, CA.

Ewing, L.C., et al. 1989. Planning for an Accelerated Sea Level Rise Along the
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320

ROLE OF EDUCATION IN POLICIES AND PROGRAMS
DEALING WITH GLOBAL CLIMATE CHANGE

MIKE SPRANGER
Program Leader for Marine Advisory Services
Washington Sea Grant Program
University of Washington
3716 Brooklyn Avenue, NE
Seattle, Washington

ABSTRACT

Much attention is now focused by government, academia, and the popular press
on the short-term and long-term effects of sea level rise and other impacts of
global climate change. Many uncertainties and much confusion are associated
with global climate change today. However, despite the ambiguity of information
and the uncertainty about future events, national and international decisions
and policies, which deal with limiting and/or adapting to climate change and sea
level rise, are now being debated and made.

Any governmental policies or programs that are adopted will need the strong
support and endorsement of the local citizenry to be successful. To date, the
majority of citizens are either unaware of the issues, problems, and potential
impacts of global climate change, or they are confused by the conflicting
information that they receive via the mass media.

Citizens in both developed and developing countries need to receive
accurate, objective information about global climate change and its implications.
More important, not only do citizens need to have a better understanding of the
processes involved and the implications of global climate change, but they, along
with the business and industrial communities, also need to receive information
on what type of local actions can be taken to respond to this issue. Regulation
alone is not enough. A long-term pro-active educational response is needed.
As is the case within the research community, an interdisciplinary, coordinated,
and international educational program needs to be developed.

This paper will . discuss the role of education and the rationale for
developing a strong, coordinated interdisciplinary educational program to deal
with the issue of global climate change. It will discuss the "Extension Model"
used by the Sea Grant Program as one possible approach. Finally, it will discuss
other possible educational options and program opportunities.

321

Legal and Institutional Implications

ROLE OF EDUCATION IN POLICIES AND PROGRAMS DEALING WITH GLOBAL CLIMATE CHANGE

The potentially devastating impact of human activity on the environment
has become the international issue of the late 1980s. It seems that one cannot
pick up a newspaper or view a television newscast in the United States without
at least one story devoted to this issue. These stories focus on such problems
as threats to the climate and damage to our populated coasts and social
infrastructure due to sea level rise resulting from greenhouse warming; damage
to plant, animal, marine, and human health from increased ultraviolet radiation
due to the depletion of stratospheric ozone; extinction of species due to
tropical deforestation; threats to marine life and human recreation from coastal
and estuarine pollution; human, animal, and environmental damage and
contamination from nuclear and hazardous waste; and damage to lakes and forests
from acid rain.

Of course, these threats are not really new. Some of the world's leading
scientists have warned about these global dangers for many years. Global climate
change is not new either. Since the dawn of creation, the earth and its
resources, the climate, and the atmosphere all have changed, since they
constitute a dynamic system. But what is new is the concentrated focus by
government, academia, and the popular press on these issues.

Why this new focus? There are many reasons. Technological and scientific
advances now allow us to better measure, model, and predict what is happening
within the earth's dynamic systems. The dedication of scientists and managers
in the 1980s to step beyond their laboratories and classrooms to discuss these
issues in the public arena has caught the attention of our government officials.
Major climate events of the late 1980s -- droughts, hurricanes, major flooding
episodes, evidence of holes in the ozone layer -- have also brought print
exposure, television air time, and international attention to environmental
issues. The result is a rising consciousness of the accelerated changes in the
earth's systems due to man's influence, particularly in the last 100 years.

However, there are many unknowns, fierce debate among the scientific
community about potential impacts, and public confusion about issues of global
climate change. Two issues of particular concern to members of the marine
community are the potential breakdown of the ozone layer and the impacts of the
greenhouse effect.

The predominant scientific opinion today is that chlorofluorocarbons (CFCs)
destroy the ozone layer, and that the consequences of enhanced ultraviolet
radiation on the biota are dangerous. Located in the thin stratospheric layer
some 15 miles above the earth's surface, the ozone layer acts as a protective
shield from the sun's lethal ultraviolet (UV) rays. CFCs have been used in
increasing quantities in a variety of industrial and consumer products because
of their properties as a stable, inert gas. However, because of this stability,
they do not break down, but rather slowly drift into the stratosphere. There,
through a series of complex reactions, they break down, and free chlorine ions
are released that destroy thousands of ozone molecules. In the last few years,
scientists have discovered an average annual worldwide ozone loss of 2%, with

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up to a 50% seasonal loss in the polar regions. The increase in UV radiation
may be devastating for humans, plants, and animals. For humans, the increase
in skin cancer may be significant; less is known about the effects on crops,
trees, and the ocean food chain. The Montreal Protocol was the historic first
step in regulating CFC production, but it may not be enough. Despite a planned
phaseout of CFCs to 50% of their levels, many scientists are urging that CFCs
be eliminated entirely, using substitutes that already exist.

The sources responsible for the greenhouse effect are well known: CFCs,
deforestation, carbon dioxide from fossil fuel combustion, and methane from
increased biological activity. There is growing confirmation among scientists
that global mean temperatures will increase. The latest computer models predict
an average global increase of up to 5*C, with rises of up to 120C in the polar
regions. This temperature change is comparable to the warming since the last
ice age. Of great concern and uncertainty are regional effects on weather, such
as storms, and particularly changing rainfall patterns. Sea level may rise by
one meter in the next 50 years. Our understanding of this problem is poor. New
models are being developed, but it may be several more years before our
predictive and analytical tools are any better at forecasting what will occur.

The scientific community is embarking on a new research plane that is
integrated, coordinated, and interdisciplinary. Millions of dollars are being
spent, or are in the process of being budgeted, for needed research that will
increase our knowledge of what is happening to the world in which we live. Also,
despite the paucity of information, scientific debate, and uncertainty of future
climatic events national and international decisions and policies are now being
debated and made to deal with the adaptation to global climate change and sea
level rise. Clearly, the global climate issue will reach the agenda of most
major governments in the 1990s, if it has not already arrived.

However, any government policies or programs that are adopted will need
the strong support of the local citizenry to be successful. To date, the
majority of citizens are either unaware of the issues, problems, and potential
impacts of global climate change, or they are confused by the conflicting
information that they receive via the mass media.

Unfortunately, to date not much coordination or thought has been given to
providing the proper type of citizen involvement and educational effort. The
educational activities that have occurred have been disjointed, with the
information based more on emotion than fact. Many educational and informational
activities are occurring, however. Following are a few that have recently been
brought to my attention:

Nonprofit Organizations

Union of Concerned Scientists (Cambridge, Massachusetts) coordinated a
"week of education" with over 200 individual projects in 47 states of the
U.S.A., and also developed a "Global Warming Briefing Packet" and an expert
speakers list.

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Legal and Institutional Implications

Oceanic Society (San Francisco, California) will include in its "Project
Ocean" educational curricula the latest information on global climate change
and its impacts on the oceans.

National Wildlife Federation has developed "Cool It," an informational
packet on the greenhouse effect and other global climate change issues.

Numerous environmental organizations have developed special newsletters,
specifically designed to deal with global climate issues. One example is
"Atmosphere," a publication of Friends of the Earth International on Ozone
Protection.

Industry Groups

American Society of Mechanical Engineers developed a briefing paper, "Energy
and the Environment" (July 1989), which took a broad look at the
relationship between energy and the environment.

National Association of Manufacturers developed a white paper, "Global
Climate Change" (July 1989), that investigated the economic issues impacted
by greenhouse gas emission reduction, targets and the risk of premature
inadequate causes of actions that may hurt, rather than help an effective
international response.

Many International, National, State, and Local Conferences

"Global Natural Resources Monitoring and Assessments: Preparing for the
21st Century" (September 1989 - Venice, Italy).

"Globescope Pacific" (October 1989 - Los Angeles California, U.S.A.),
sponsored by the Global Tomorrow Coalition Project, brought 1,000
individuals together to begin discussions to launch a decade of creative
actions to achieve sustainable development.

"Climatic Fluctuations and Their Socio-Economic Impact Concerning Countries
Around the Atlantic Ocean" (November 1989 - Toulouse, France).

"Environmental 2010" (November 1989 - Seattle, Washington, U.S.A.),
sponsored by the Washington Department of Ecology and U.S. Environmental
Protection Agency, brought 600 individuals together to discuss State of
Washington environmental issues and priorities and strategies to deal with
them.

"Northwest Sea Level Rise Conference" (December 1989 - Seattle, Washington,
U.S.A.), sponsored by the Washington Department of Ecology to bring state
agency officials, politicians, and interested individuals together to focus
on the implications of sea level rise for the Pacific Northwest. Different
approaches will be presented for dealing with the issue.

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"World Conference on Preparing for Climate Change" (December 1989 - Cairo,
Egypt).

European Conference on Landscape- -Ecol ogi cal Impact of Climatic Change
(December 1989 - Lunteren, The Netherlands).

"Climate Change: Planning Ahead for South Carolina" (January 1990 -
Charleston, South Carolina, U.S.A.), sponsored by the South Carolina Sea
Grant Consortium to bring together national and state experts to present
a scientific overview of climate change and its implications for South
Carolina.

"Global Warming: A Call for International Coordination of Scientific and
Policy Issues Facing All Governments" (April 1990 - Chicago, Illinois,
U.S.A.).

"International Conference on the Role of the Polar Regions in Global Change"
(June 1990 - Fairbanks, Alaska, U.S.A.).

"Beijing International Symposium on Global Change" (August 1990 - Beijing,
Peoples Republic of China).

"Chemistry of the Global Atmosphere" (September 1990 - Chambrousse, France),
sponsored by the Commission on Atmospheric Chemistry and Global Pollution.
Seventh Annual International Conference.

Hats Media

It appears that saving the earth's environment will blanket network and
cable television channels during 1990 in the United States -- everything from
news specials to sit-com episodes will address this issue.

Turner Broadcasting System, Inc. (TBS) began airing the half-hour program
"Earthbeat" on October 15, 1989, which is an advocacy- oriented program
showing how individuals, countries, and corporations can help save the
planet. Earthbeat has an activism format, such as using telephone surveys
to record viewer opinion on various issues, and inviting viewers to call
'in to put their names on "electronic petitions" that will be sent to
.politicians and corporations. Producer Jeanette Ebaugh states: "TV is the
most powerful tool in the world, and it wasn't being used to aid the most
serious issue of our time.... 11 ("TV is Giving Star Status to Environment"
Wall Street Journal, 10/2/89).

TBS is also working on an animated cartoon series to be called "Captain
Earth."

TIME Magazine in January 1989 named its Man of the Year "The Endangered
Earth."

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Lega7 and Instftutiona7 Imp7ications

Columbia Broadcasting System (CBS) in September 1989 began airing 60-second
"Earth Quest" spots. CBS News also plans on showing five 1-hour specials
on the environment in April 1990 in conjunction with Earthweek.

Barbra Streisand, Kevin Costner, and several other Hollywood celebrities
will host a 2-hour special called "A Practical Guide to How You Can Save
the Planet," to be aired on Earth Day, April 22, 1990.

Olivia Newton-John (Austral ian-born pop singer), United Nations goodwill
ambassador for the environment, plans to air a television Christmas special
entitled "A Very Green Christmas."

Puppeteer Jim Henson (creator of The Muppets) is developing a children's
show about nature to be called W.I.L.D."

Although there appear to be many such efforts, most are not coordinated or
integrated with one another. Neither are they tied to a strong research base
that can provide the citizenry with accurate information on the issues and the
latest findings about global climate research. Nor are they really aimed at
the local citizenry of the world.

There is a need for citizens in both developed and developing countries to
receive accurate, objective information about global climate change and its
implications. More important, not only do citizens need to have a better
understanding of the processes and the implications involved, but they, along
with the business and industry communities, also need to receive information on
what type of local actions can be taken to respond to this issue. Government
programs and various regulations alone are not enough.

As envisioned by Jean Jacques Rousseau, John Locke, John Stuart Mill, and
other e i ghteenth -century philosophers, democracy requires that all citizens have
the right to influence political decisions that affect them. A basic assumption
of this philosophy is that all citizens are -- or can be -- essentially equal,
in both their concern for public issues and their competency to make decisions
about them. However, to make these decisions, citizens need accurate and
understandable information. Unfortunately, many of the recent articles on global
change and ozone depletion are sensational, technical, or too abstract for the
general public, and they really do not help people make a connection between
their everyday actions and the impending long-term global changes that will
probably take place.

A long-term proactive educational response is needed that is research-based
and multi-pronged for both formal and informal settings. As is the case with
global climate research, the educational program needs to be interdisciplinary,
coordinated, and international in scope. One educational model that already
exists within the United States and that could be used in this effort is that
found within the Land Grant and Sea Grant systems. The Land Grant system was
established around the turn of the century, focusing on increasing agricultural
productivity. The Sea Grant system was established in the mid-1960s to encourage
the understanding, wise use, and conservation of our marine resources. Both

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systems use a three-pronged effort involving research, education, and extension
and advisory services to carry out their mission.

With funding from federal, state, and local sources, a unique partnership
among federal and state governments, major universities, and industry has been
forged through the years. For the Sea Grant Program, the majority of its
operating funds come from the U.S. Department of Commerce's National Oceanic and
Atmospheric Administration (NOAA). Sea Grant's research and advisory service
programs around the country have worked at some time or other with virtually
every one of NOAA's agencies. In general, Sea Grant programs work most closely
with NOAA's National Marine Fisheries Service (NMFS), National Weather Service
(NWS), Office of Coastal Zone Management, Environmental Research Laboratories,
and National Ocean Survey.

In the rest of the federal arena, Sea Grant has worked closely with the
U.S. Coast Guard, U.S. Fish and Wildlife Service, regional fisheries management
councils, U.S. Army Corps of Engineers, U.S. Department of Agriculture, and U.S.
Environmental Protection Agency. Most of these contracts are made on the
regional or local level and take the form of information exchange or joint
sponsorship of advisory service projects like conferences or publications. The
resources of these federal agencies often enhance Sea Grant's ability to solve
a local or regional problem, and the federal agencies, in turn, often use Sea
Grant's communications network.

An intricate infrastructure of public outreach is in place through the Land
Grant and Sea Grant system of campus-based specialists and field agents. Within
this system, there is a dissemination point within every country of the United
States that could be mobilized for information exchange and technology transfer
related to the global climate issue. Additionally, since these programs are
housed at various universities around the country, there is yet another mechanism
to tap into a large portion of the research community within the United States.

In dealing with the issue of global climate change, these two systems could
be harnessed in several ways. First, the Sea Grant and Land Grant networks could
join in partnership with other research programs already in progress to provide
hard scientific data on the effects of the projected global changes on the marine
and coastal environments. Second, we could bring regional, national, and
international extension initiatives to educate the general public about the
severity of the problems facing us, and even more, about steps that might be
taken to deal with the causes on an individual level. Our educational approach
has always been proactive and positive. Our mandate is to provide citizens with
relevant facts about a issue. If there is controversy or uncertainty, our
educational formula is to provide citizens with the various options and actions
that might be taken to deal with the issue. Our extension component provides
local technical assistance and public information programs to citizens and links
them with university research. We take a non-advocacy point of view, striving
to present the best information to citizens so that they can make the best
decisions about our natural and marine resources.

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Legal and Institutional Implications

To be effective, an educational program needs to be long-term and to have
both formal and informal elements. Regarding formal education, the latest
scientific findings concerning global environmental changes must enter the school
systems of the world. The future resource managers of the world need to become
environmentally aware and informed. They need to develop an environmental
literacy that reconnects them with the world in which they live. At present,
the Sea Grant Network is awaiting word from the National Science Foundation on
just such a project, entitled "Interpreting Current Research on Global
Environmental Issues for Teachers and Students." The goal of the three-year
project is to create among middle-school teachers and their students an enhanced
awareness and understanding of global environmental issues by providing a
structure for the transfer of marine and aquatic research results and methods
to middle-school educators throughout the U.S.A. From this prototype program,
additional informal education materials could be developed for youth that could
be disseminated throughout the United States through the Land Grant network via
its 4-H and Youth Programs. I, along with my counterpart in the Hawaii Sea Grant
Program, are also working with the National Marine Educator's Association to
Develop a one-day training session on global climate change at their annual
meeting, scheduled for August 1990 in Hawaii.

Informal educational activities also need to be developed to educate adults
on the issues and the associated problems, and their responsibilities to take
action. To achieve the objectives of informed citizen participation and action,
we must provide individuals with numerous opportunities to acquire the skills
and information necessary to change their behavior and lifestyle. It must also
be stated that working with the adult population, one needs to develop a
different educational strategy. Until recently, adults were often treated the
same as students in any elementary, secondary, or college classroom, with little
attention paid to differences in their experiences, needs, and motivations. The
proliferation of adult education and training experience has brought new ways
of thinking about how adults learn and change behaviors. In fact, the special
needs, and characteristics of adult learning were recognized by Malcolm Knowles,
who created the word "andragogy" to describe "the art and science of helping
adults learn," which is distinguished from "pedagogy," which deals with teaching
children.

Several formal and informal meetings have already taken place between Land
Grant and Sea Grant administrators to discuss coordination of global climate
educational efforts. These discussions will continue as we develop joint long-
term educational strategies. The logical next step should be to broaden these
discussions with other local, state, national and international government and
nongovernment actors who are developing educational programs, in order to avoid
duplication of effort and to maximize use of the funds available for such
activities. Many of my counterparts in the Sea Grant network have already made
contacts with various local and state agencies to jointly develop educational
programs and materials. National and international coordination and cooperation
are also needed.

There are many examples of informal educational programs that could be
developed. Many of these are not new to extension educators. However, the

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educational tools that could be used could be expanded to include the latest in
print and audiovisual media, including cable television and satellite hookups.
Here are a few of the generic programs that could be developed:

Initiate Programs Designed to Prevent Further Global Change

Develop educational programs to stress reductions in CO, emissions through
energy conservation, resurrecting projects that were implemented in the 1970s.
Improving home insulation, increasing automobile mileage, switching to cleaner
fuels for home and work, conserving electricity at home and work, and supporting
development and use of mass transit are a few examples that could be stressed
in this program. Educational programs could also be aimed at recycling,
reduction of excess packaging, and reduction of nonessential use of CFCs.

Design Programs That Will Directly Mitigate Future Global Change or its Effects

Implement tree-planting programs. We could also develop (1) educational
projects related to protection from increases in ultraviolet (UV) radiation
increases, and (2) educational materials and liaisons with state agencies to
factor sea level rise into coastal planning efforts.

Encourage Needed Research to Answer Uncertainties About Global Warming and Ozone
Depletion

Promote research that would close gaps in our knowledge of in situ effects
of enhanced UV on marine plankton, coral, and food plants. Study the economic
impact of UV and global warming so that costs or mitigation and prevention can
be compared and evaluated. Initiate sociological studies to predict public
response to global change.

Initiate Leadership Develogment in Citizens on Global Climate Change Issues

Provide educational programs for citizens so that they understand the public
policy process, and how they can become effective an part of the process.

Develop Educational Programs That Encourage an Environmental Ethic

Provide educational programs that are interdisciplinary and that provide
a global ethic that recognizes the interrelationship of our air, water, and land
resources.

In developing an educational program to empower an individual toward action
or behavioral change, several guidelines and techniques should be remembered to
ensure success.

Make the issue the individual's problem. It's not just the
government's problem. Personalize the problem to solicit action.

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Legal and Institutional Implications

� Switch from an institutional orientation to an individual orientation.
Switch from a "this is what is important to us" mentality to one of
"what is important for the individual."

� Repetition counts. People rarely understand the issue the first time.
It often takes many times to change an opinion, behavior, etc. Keep
the message in front of the individual.

� Don't sell the process, sell the outcome. Only the sponsoring
organization is interested in how it happened. Individuals are only
interested in what is in it for them.

� "Less is more." Don't complicate your educational program with too
much detail. Keep it simple and as nontechnical as possible.

� Keep the issue in its context.

� Don't just speak to those already committed to the cause. Use
nontraditional means to get the information out to the public.

� The biggest challenge is keeping the issue in front of the individual,
and keeping it on the public agenda.

In conclusion, although it appears that the global environmental crisis is
extremely serious, it also is one that is ripe with opportunity for positive
social changes. As some of you may know, the Chinese symbol for crisis consists
of two characters. One means danger, and the other means opportunity. The
scientific community has clearly articulated the danger, and the alarms have been
sounded throughout the world. However, it appears that there also is a
responsibility and an obligation for all of us -- educators, policymakers,
scientists -- to seize the opportunity that this global issue presents to unite
us on an issue that cuts across economic, social, political, geographic, and
environmental boundaries. There clearly is a role for both government action
and local responsibility. International government incentives, regulations, and
agreements will need to be put into place to deal with this global issue.
Individual actions and choices that involve an understanding of the global
environment in which we live are also needed. With the lessening of tensions
between East and West, we may have an opportunity to turn our attentions, funds,
and manpower away from weapons of destruction and instead turn them to activities
that will prevent or lessen the destruction of our planet.

BIBLIOGRAPHY

Byerly, R. Jr. 1989. The policy dynamics of global change. EarthQuest 3:1,
Spring.

Clark, W.C., and R.E. Munn, eds. 1986. Sustainable Development of the
Biosphere. Cambridge, England: Cambridge University Press.

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Kitsos, T.R., and D.M. Ashe. 1989. Problems in the institutionalization of the
U.S. global change program - a non-scientist's viewpoint. Earthquest 3: 1,
Spring.

Knowl es, M. 1980. The Modern Practice of Adult Education. Chicago, IL:
Association Press.

Managing Planet Earth. 1989. Scientific American, Special Issue, 261:3
September.

Schneider, S.H. 1989. Global Warming: Are We Entering the Greenhouse Century.
San Francisco, CA: Sierra Club Books.

Waldrop, M.M. 1989. The U.S. global change program - a political perspective.
EarthQuest 3:1, Spring.

Wall Street Journal. November 2, 1989. TV is giving star status to environment.

World Commission on Environment and Development. 1987. Our Common Future. New
York: Oxford University Press.

331

ECONOMIC AND FINANCIAL
IMPLICATIONS

FUNDING IMPLICATIONS FOR
COASTAL ADAPTATIONS TO CLIMATE CHANGE:
SOME PRELIMINARY CONSIDERATIONS

JOHN CAMPBELL
Ministry for the Environment
84 Boulcott Street
Wellington, New Zealand

INTRODUCTION

The purpose of this document is to explore the implications for funding of
options for coastal adaptation to climate change. The paper focuses on issues
of allocation of financial resources for coastal adaptation and considers
priorities for immediate assistance.

BACKGROUND

There is considerable uncertainty about the effects of climate change upon
coasts. Impacts may arise from rising sea level, increased storminess, changed
wave climates, and changes to freshwater and sediment contributions brought about
by inland climate changes. There may be significant lags in the manifestation
of the impacts of climate change on the coast.

Almost all coastal countries will be affected by rising sea level or other
changes brought about by climate change. Many countries have large populations
in low-lying areas, and a number have considerable economic investment in their
coastal zones. According to demographic projections, the current global
population will have doubled over current levels before greenhouse gases reach
twice their pre-industrial levels. A great deal of this population growth will
be in coastal cities and other lands likely to be vulnerable to sea level rise
and other effects of climate change.

Coastal erosion and loss of natural coastlines, often associated with
unsustainable development projects, are commonplace in many areas. There is an
urgent need to ensure that current practices for using coastal resources are
environmentally sound, which could have implications for the funding of coastal
development projects, irrespective of the issue of climate change.

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Economic and Financial Implications

The IPCC Response Strategies Working Group (RSWG) has prepared a paper on
financial measures as part of its Task B activities. A similar paper has been
prepared on technological development and transfer measures. These papers serve
as the basis for the following discussion of funding implications for possible
coastal adaptation to climate change.'

INTERNATIONAL COOPERATION

Climate change is a global problem whose solution will require international
cooperation. This necessity has been widely recognized with respect to
strategies for limiting global warming and the encouragement of their adoption
by all countries. As a result, most discussion regarding financial or
technological assistance to developing countries has focused on these activities.

However, the impacts of climate change are not likely to fall evenly, and
many of the nations affected will have insufficient financial resources to adapt
effectively. There is, therefore, an equal need for international cooperation
to ensure that no countries are unduly or excessively burdened by the effects
of climate change or the costs of adapting to them.

All nations contribute to the greenhouse effect, but the industrialized
nations have contributed the greatest share. Moreover, these nations have many
of the resources, both financial and technological, necessary to ensure effective
adaptation. From this perspective, the industrialized nations have a special
-responsibility to assist the developing countries that are adversely affected,
or likely to be adversely affected, by changing climate.

In some sectors, adaptation may yield some positive economic outcomes (for
example, changed climate conditions may enhance agricultural productivity).
However, while some opportunities for gain may unfold in coastal areas, they are
likely to be relatively uncommon.

THE MAGNITUDE OF FINANCIAL REQUIREMENTS

The Task B report notes that "the special needs of developing countries
including their vulnerability to problems posed by climate change and their lack
of financial resources must be recognized and assistance tailored to meet their
individual needs. Financing requirements might be considerable." The probable
quantum of financing requirements is, however, unknown. This applies to the
likely costs of funding options of limiting, as well as adapting to, the effects
of climate change.

'The Task B activities of the RSWG program focus on measures to implement
response strategies or policies. The task includes five specific areas: Legal
Measures and Processes, Technology Development and Transfer Measures, Financial
Measures, Public Information and Information Measures, and Economic (Market)
Measures.

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Campbell

The costs of adapting to the impacts of climate change on coastal areas
may include capital investment not only in protective works but also in the
maintenance of these works. If sea level continues to rise, the works may have
to be replaced or augmented. Similarly, land use planning methods to reduce
vulnerability to sea level rise may require constant adjustment to changing
conditions. Therefore, it is important to recognize that financial requirements
for adapting to climate change may include not only initial costs but also
ongoing costs as well. If limitation strategies either are not implemented or
fail, the costs of adaptation will grow through time.

One adaptive response is to do nothing. Recourse to this option may be
widespread if financial assistance to vulnerable communities is not available.
However, under such conditions, there may nevertheless be massive costs in terms
of economic and social disruption, possible destruction of property, and, indeed,
loss of life. International disaster relief for coastal calamities would become
increasingly common. This relief may be needed at the same time that demands
on donors are growing for other climate-related hazards, such as drought.

There is an urgent need for a detailed assessment of the costs of the
impacts of climate change and of various adaptive strategies for communities at
risk. There is also a need for indications of the likely timing of the financial
requirements for coastal adaptation.

FINANCIAL RESOURCES FOR COASTAL ADAPTATION

The Task B report on financial measures makes a clear distinction between
(1) generating funds for responding to climate change and (2) allocating these
funds. It is an important distinction: the generation of financial resources
is a generic issue that is not substantially different for any of the response
subgroups, be they for limitation or adaptation. However, linking sources of
funds to emissions of greenhouse gases may serve as an incentive for limiting
emissions. Such an approach should nevertheless take into account that while
adaptation may be necessary because of past emissions, linking responsibility
for offsetting the costs of adaptation to current "emitters" may especially
disadvantage countries that do not have a long history of, and have not yet
benefited from, industrialization.

THE GENERATION OF FUNDS

There are a variety of suggestions for the generation of climate change
funds, ranging from building on current multilateral and bilateral arrangements
and using voluntary contributions to making specific calls for an international
fund based on greenhouse gas emissions. The source of funds is a generic issue
that is most appropriately addressed in the Task B work of the Response
Strategies Working Group. However, the need to provide information on the likely
demands on such a fund, its magnitude, and the areas to which it may be applied,
is the responsibility of the coastal and terrestrial subgroups. This paper
focuses on these issues with respect to coastal adaptation.

337

Economic and Financia7 Imp7ications

Funding to assist the adoption of limitation strategies may ultimately
serve the common interests of all countries in ensuring that global climate does
not change. Such common interest may not be as strong in the consideration of
helping individual countries cope with the consequences of climate change. In
particular, those countries that contribute little to the problem may have little
leverage in seeking assistance.

If the generation of funds is based on greenhouse gas emissions, the size
of the fund will decrease as emissions fall. In this event, while the magnitude
of long-term climate change may be reduced, the shorter- and medium-term impacts
may not be avoided due to lags. Those who must raise financial resources to
assist adaptation may have to seek other sources.

ALLOCATION OF FINANCIAL RESOURCES

There are four major issues relating to the allocation of funds: (1) the
allocation of financial resources between limitation and adaptive strategies,
(2) allocation among the various adaptive strategies, (3) determination of who
should receive such funds, and (4) determination of what institutional
arrangements are likely to be appropriate.

Limitation versus Adaptation Strategies

Much of the Task B work on financial measures focuses upon the question of
promoting limitation strategies. It states that "priority should be given to
those financial measures and policies which can have an early impact in reducing
emissions of greenhouse gases and which make economic sense in their own right."
While the purpose of this paper is to outline the funding implications of coastal
adaptation, it is important to note the link between limitation and adaptation.
This is portrayed schematically in Figure 1.

Under Scenario A in the figure, in which there is no limitation response
and in which global warming does indeed occur, there will be a growing need for
financial resources to support various adaptive responses. The demand upon these
resources may grow if the area at risk increases over time. Early strategies
to deal with predicted changes may prove inadequate if global warming continues
unabated beyond the dates used in impact scenarios or for planning purposes.

In Scenario B, limitation strategies are only partly successful in reducing
greenhouse gas emissions and thus serve only to slow the rate of climate change.
Under this scenario, there will be an early demand for funds to support the
implementation of limitation strategies. The financial requirements for
limitation strategies will fall as initial technological development is
completed, industrial conversion costs are eliminated, and new industrial
developments include the strategies as normal processes. The need for adaptation
will rise initially at the same rate as outlined in Scenario A owing to lags in
the atmospheric and oceanic response to greenhouse gas emissions up to the time
when limitation strategies are initiated. At some point, the rate of impacts
of climate change and demands upon resources for adaptation to it will slow.

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CiMpbe I I

Scenario A: No Limitation Scenario B: Partial Limitation

Scenario C: Stepwise Limitation Scenario D: Complete Limitat6on

J
TM

---- adaptation costs
limitation costs

Figure 1. Conceptual timepath of costs for limiting and adapting to global
warming for four scenarios on the timing of efforts to curtail emissions.
Because adaptation and limitation costs are not necessarily drawn to the same
scale, the reader should not attach any significance to the points at which the
curves cross.

However, because the limitation is incomplete, demands for resources to enable
increasing implementation of adaptive options will nevertheless continue to grow"
albeit at a slower rate.

Under Scenario C, limitation strategies are agreed upon and implemented on
a step-wise basis. Depending on the completeness of the limitation strategies
finally chosen, the demands upon resources to enable adaptation will slow,
notwithstanding the lags in the response.

In Scenario D, heavy initial support for limitation strategies sees a
stabilizing of atmospheric concentrations of greenhouse gases. While there will
still be some demands for assistance for adaptation to the impacts of increases
occurring before concentrations are stabilized, adaptation costs will eventually
fall. Depending, however, on what point the system stabilizes, there may be an
ongoing need to maintain options that have been taken to adapt to a new status
quo.

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Economic and Financial Implications

The implications of this model of financial requirements are clear. The
greater the rate of implementation of limitation measures, the less serious the
impacts may be, and the less onerous the burden of coping with or responding to
them. It is extremely important that the relative costs of limitation and
adaptation are obtained so as to indicate the order of magnitude of financial
requirements for the various options.

Moreover, there is no current certainty as to what the effects of climate
change will be on coastal areas and indeed what the time frame of their
occurrence will be. It is therefore important, given this uncertainty, that
immediate emphasis be on limitation, and funds should be allocated accordingly.

Funding Needs for Coastal Adaptation

If strategies to limit the emissions of greenhouse gases are successful,
the destructive impacts upon coastlines may be reduced. However, there is
considerable concern that even if limitation strategies do succeed, the climate
change already set in motion will take its toll. Moreover, initial limitation
efforts are likely to only partly reduce the rate of atmospheric change.

Consequently, there are some urgent requirements for coastal adaptation:

� improving scientific understanding of climate change, sea level rise,
and other effects, such as tropical cyclones;

� monitoring sea level and coastal changes;

� undertaking vulnerability studies to identify those areas most likely
to be prone to the effects of sea level rise;

� conducting site-specific impact assessments, especially in areas
considered to be vulnerable to sea level rise;

� initiating public education, forward planning, and consultation among
communities likely to be affected by the coastal impacts,of climate
change;
� investigating into and developing the full range of coastal adaptations,
including nonstructural or nonengineering option; and

� providing information transfer of existing coastal adaptation strategies
and training professionals in implementing them.

It is equally important to foster adaptive strategies that will be of
benefit even if there is no change in sea level. Such strategies include the
following:

� improving the disaster preparedness of vulnerable areas; and

� fostering sustainable coastal management programs in all areas.

340

Campbell

International development agencies involved in funding projects in coastal
areas should ensure that the projects foster sustainable coastal development.

There is a need to establish the level of assistance required to meet these
initial priorities for coastal adaptation. An indication of probable long-term
funding requirements is also necessary. We expect these long-term requirements
to be much greater than the initial needs. Because the need for funds is likely
to substantially escalate, it may be appropriate to begin now the process of
developing such a fund.

Criteria for Allocating Funds

If financial requirements are extremely high, demands for assistance may
exceed the funds available. Thus, criteria for allocation of funds may be
necessary. Such criteria may include both evaluation of the recipient's
requirements and assessment of the adaptive option being promoted.

The scale of financial resources needed may vary considerably, depending
on the nature of the adaptive option and the area and impact being addressed.
While considerations of cost-efficiency should apply in deciding priorities for
allocation, the social, cultural, and environmental implications should not be
ignored.

The following is a list of possible criteria that could be incorporated.

The Recipient

� Financial resources to the recipient;

� Contribution of the recipient to the greenhouse effect;

� Importance of the area at risk in a national context:

- proportion of national land area at risk;

- population of area at risk;

- economic importance of area at risk;

- social, cultural, and ecological importance of area at risk; and

- threat to national sovereignty.

The Proposed Adaptation

� Cost of adaptive option;

� Effectiveness of adaptive option;

� Impacts of adaptive option:

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Economic and Financial Implications

- social,

- economic,

- ecological, and

- cultural.

Sustainability of adaptive option, taking into account the likelihood
of continuing climate change impacts, including sea level rise.

Since the greatest need for funds will occur well in the future, there is
time for these criteria to be more carefully developed. The complexity of the
problem and the lack of any easy answers point clearly to the urgency of ensuring
that limitation strategies are adopted promptly.

Rnstitutional Arrangements

The Task B financial measures paper explores two main options for
institutional arrangements. First, existing multilateral and bilateral
institutions and arrangements may be built on, and second, new mechanisms, such
as an international fund, could be created. In the case of the international
fund, the emphasis is on fund generation, with existing institutions maintaining
the role of allocation.

Given the wide range of options for the use of funds to respond to climate
change, new institutional arrangements may be necessary to coordinate and to
ensure that equitable, timely, and effective allocation of resources is achieved.
This will help ensure that limitation strategies are widely accepted, and that
appropriate adaptation options are widely available.

TECHNOLOGY DEVELOPMENT AND TRANSFER

As with funding questions, much of the discussion to date on technology
development and transfer has focused on measures to reduce emissions of
greenhouse gases. However, there is also an urgent need for the development of
innovative and sustainable adaptive options. These include both technical and
nontechnical measures. Similarly, there is a need to train people to undertake
and manage adaptation to climate change. Areas where there is such need include
the following:

� impact assessment,

� vulnerability analysis,

� monitoring of coastal change,

� disaster preparedness planning,

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Campbe7l

* engineering, and

* land use planning.

A variety of means of technology transfer can be considered. These include
training programs, technology research centers, extension services, technology
advisory committees, technology research and development, technology conferences,
and pilot transfer programs. The existing multilateral and bilateral
arrangements for technology transfer should be strengthened and expanded. And,
most important, in developing and transferring technology, the social, cultural,
and environmental needs of the nations receiving the technology must be accounted
for.

CONCLUSION

Adapting to climate change may require very large financial resources.
Some countries will need assistance, particularly those for which coastal impacts
will impose an unacceptable risk and those for which adaptation activities will
impose an undue burden.

Demands for financial resources to adapt to the coastal impacts of climate
change will compete with other response requirements, including limitation
strategies and adaptation to noncoastal impacts. There is a need to evaluate
the probable magnitude of these financial needs and their timing.

Some time will pass before the coastal impacts of climate change are clearly
manifested. There is an urgent need to support limitation strategies in the
first instance to reduce the rate of change that is likely to occur.
Nevertheless, there will be some immediate needs for anticipatory adaptation,
particularly for monitoring, assessing vulnerability, and developing responses.
Funding of development projects in coastal zones should encourage options that
are sustainable in the long run.

DISCLAIMER

This paper has been prepared as a draft chapter for the Coastal Zone
Management Report of the Response Strategies Working Group (RSWG) of the
Intergovernmental Panel on Climate Change (IPCC). The purpose of this draft is
to stimulate discussion at the Miami meeting of the CZM subgroup of the RSWG to
be held in November 1989. As such, it represents preliminary views only. It
does not constitute the policy of the New Zealand Government.

This paper was prepared without detailed information regarding the impacts
of climate change on coastal areas or information about the range of possible
adaptive options and their costs. The information produced in these proceedings,
as well as a second conference in Perth, Australia, is expected to contribute
to the final version of this paper as a chapter of the IPCC report.

343

PREPARING FOR SEA LEVEL RISE AT THE LOCAL LEVEL

JAMES B. EDMONSON, IV
South Central Planning and Development Commission
Thibodaux, Louisiana

ABSTRACT

In 1984, Terrebonne Parish in Louisiana became the first local government
in the world to officially recognize the greenhouse effect, sea level rise, and
their corresponding economic, social, and cultural implications. With current
relative sea level rise rates of 1.03 to 1.30 cm/yr, both immediate and long-
term solutions had to be addressed. After nearly 10 years of disjointed and
misdirected state and federal activities, these parishes (or counties) realized
they would have to undertake the management of their coastal areas themselves.
Any program they developed would have to be long term and would require the
support of their citizenry. Thus, they fashioned a multi-pronged comprehensive
approach.

This paper examines the elements of this approach. The research element
includes over 100 reports on the causes and effects of sea level rise and
possible local solutions. Education includes billboards, public service
announcements, and school curricula. Lobbying includes the creation of a grass-
roots, non-profit organization. Funding includes a tax on petroleum extraction
royalties. Finally, design and implementation of construction projects relied
on improved coordination of local, state, and federal officials.

INTRODUCTION

The landscape of coastal Louisiana has always been changing. The
Mississippi River works and reworks its delta plain and inner continental shelf
through the combined effects of the constructive and destructive forces of the
delta cycle and fluctuations in sea level. Through the last phases of the
Holocene transgression, the mighty Mississippi built six major delta complexes.
Today, active delta building occurs in only 20% of the delta plain and is
restricted to the Balize delta of the Modern complex and the Atchafalaya delta
complex. The remaining 80% of the delta plain consists of four abandoned delta
complexes (Penland et al., 1988). It is these abandoned delta complexes that
provide us an excellent living example, sped-up in geologic time, of the
impending effects of sea level rise in other, more stable, coastal environments.

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Economic and Financial Implications

The apparent and relative rise in sea levels will affect the physiography and
the social structure of the coastal areas. Examined herein are the physiographic
changes resulting from relative sea level rise within the south-central region
of Louisiana and its inhabitants' reaction thereto.

LOUISIANA'S PHYSIOGRAPHY

The landscape of south-central Louisiana is dominated by abandoned
distributaries of the Mississippi delta complex. The southern two-thirds of the
region is dominated by southward radiating, abandoned distributaries, and their
associated interdistributary basins. At the Gulf of Mexico lie two barrier
shoreline systems: the Isles Dernieres and the Lafourche. The northern one-
third of the region is bisected by the active channel of the Mississippi River
and its abandoned back swamp habitats. Lake Pontchartrain lies at its northern
border.

Because the region is being influenced by the abandonment and transgressive
phase of the delta cycle, rather than the progradation phase, it is experiencing
the accelerated effects of a global sea level rise. The combined effects of
subsidence and sea level rise are termed "relative sea level rise." Penland et
al . (1988) define relative sea level rise as the long-term, absolute vertical
relationship between land and water surfaces, excluding the short-term effects
of wind and astronomical tides. Relative sea level rise in south Louisiana is
controlled by seven major factors: eustasy, geosyncline downwarping, compaction
of Tertiary and Pleistocene deposits, compaction of Holocene deposits, localized
consolidation, tectonic activity, and subsurface fluid withdrawal. Although
subsidence is the primary cause, the resultant effect of these factors is a
regionally recorded rise in relative sea level between 1.03 and 1.30 cm/yr.
Potential sea level rise is estimated to be 0.62-2.80 m over the next century
(Penland et al., 1988).

The combination of relative sea level rise, the abandonment of the delta
complex, and abusive mineral extraction practices has caused drastic landscape
changes. Land loss rates have at times exceeded 17 acres a day. One parish,
Terrebonne, has had losses of 2,053 hectares (ha)/yr. From 1955 to 1978, this
same parish lost 43,314 ha of its land area, while the region's barrier islands
have steadily decreased at an average rate of 0.27 kM2/yr (Wicker et al., 1980;
Penland and Boyd, 1981; Penland et al., 1985). Specific social impacts of this
massive destruction are already apparent.

For example, the potable water supply of the city of Houma, located in
Terrebonne Parish and nearly 50 miles from the Gulf of Mexico, has already been
contaminated by saltwater intrusion. In neighboring Lafourche Parish, the only
north-south highway linking workers to the region's largest Outer Continental
Shelf support staging area has been periodically washed out. Also at risk are
Louisiana's vast, unique wetlands, which are a natural factory for the production
of renewable resources. Louisiana's annual production value for shrimp is $50
million; oysters, $4 million; menhayden, $80 million; fur and hides, $8 million;
and recreation, $175 million. Also at risk is the region's property,

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Edmonson

infrastructure, homes, and businesses, with a total 19V assessed value of
$1,301,048,653 (Louisiana Tax Commission, 1989).

Until the 19th century, settlement of south-central Louisiana tias sporadic.
The population consisted entirely of Native Americans until the early 1700s.
White settlers explored the Lafourche area in 1699. Throughout the 1700s,
Spaniards and Germans from New Orleans and French Canadians from Nova Scotia
settled the area. They sought the solitude and bountiful hzrvests of the
bayou/marsh/swamp environment. These early settlers understood, however, the
seasonal cycles of the region. Thus, they built their homes on stilts, migraIAne,
seaward and then back inland with fluctuations of the local relative sea level.

Today, 310,626 people inhabit the six-parish area of south-centrzl
Louisiana. They produce the nation's largest shrimp catch and the second largest
oyster catch, and contribute substantially to the state's ranking of second in
oil, first in natural gas, and first in North America's fur a@d hide harvest.
The infrastructure to support these basic industries and their associated
extraction activities is substantial. Due to the region's unstable near and
subsurface conditions, the cost to construct new infrastructure and maintain
existing service is high: a new four-lane, poured-concrete highway can cost in
excess of $3 million per kilometer. Maintenance and protection of existing
services, residents, and businesses is further complicated, since 85% of the
4,682-square-mile region is open water or wetland habitat. The remaining 15%
is situated at elevations between 0.5 and 5 meters above mean sea level . Nearly
half of the region's residents live in areas less than 3 meters above mean sea
level. Other factors further exacerbating the effects of relztive sea level
rise include the leveeing of the Mississippi River and the damming of Bayou
Lafourche, the uncontrolled and capricious dredging of canals for access to oil
fields, the water dependency of the region's industrial and commercial base, the
influx of ranch-style homes placed on a poured slab at natural ground level, and
hurricanes.

One must ask, why do the people continue to stay? Is not retreat the
answer? In coastal areas developed with resorts, retirement homes, and guest
houses, this very well may be the answer. But, in coastal Louisiana, the
majority of the residents' livelihood is directly or indirectly tied to its
resource extraction and processing industries. Because of the massive size of
the delta plain and the inner and outer continental shelf area, the resource
extraction activities must be located within the delta itself in order to
efficiently extract the resource. As long as consumers demand these resources
in the market place, an abundant labor supply must likewise reside within the
delta to avoid lengthy commuter trips and costly highway infrastructure to move
them in and out of the delta. Similarly, and until the market dictates
otherwise, selective protection of the infrastructure and the delta's productive
estuary must be accommodated. Eventually, the river and the sea may very well
win this battle. However, barring major catastrophes, the region's inhabitants
and its industries will continue to retreat gradually, as is already the case.

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Economic and Financial Implications

PAST EFFORTS TO CONTROL FLOODING

Louisiana's first attempt to protect its people and industries began after
the great Mississippi River flood of 1927, which displaced thousands of residents
and destroyed many businesses. Upon surveying the damage, President Coolidge
called for the construction of massive guide levees along the entire course of
the Mississippi River. At the time, we did not realize that this effort
triggered the massive destruction of the delta. No longer was the river to flow
freely and nourish its resource-producing habitats. While the levees provided
protection from riverine flooding, nothing was done to protect residents against
coastal flooding until much later in the century.

Between 1927 and 1970, the U.S. Army Corps of Engineers became obsessed
with controlling the river. All efforts were focused on navigation, river
flooding, and backwater flooding caused by the decreasing slope of the river
channel. In later years, the Corps built several diversion structures along the
river's course, but these too were designed to protect against flooding, and not
to enhance habitat.

Midway through the century, spurred by the development of the submersible
drilling platform, the rush for black gold exploded throughout Louisiana's
wetlands. With all attention focused on the oil boom, little notice was given
to the initial destruction of the delta, except in close scientific circles and
by residents of the lowest-lying areas. Attention was first drawn to the
wetlands by the destruction caused by the now well-defined network of dredged
oil and natural gas access canals. Probably not until the mid 1960s and early
1970s was the massive ongoing destruction of the wetlands and endangerment to
communities beginning to receive public attention and debate.

Ultimately, as a result of the nation's Coastal Zone Management Act, by
the late 1970s the state government began to examine the problems of the delta.
In 1978, the Louisiana Department of Natural Resources (DNR) completed its draft
Coastal Zone Management Program, including the option for local program
participation by the coastal parishes. The state's program was approved in 1980.
However, the local programs have been developing slowly, because the state
refused to relinquish control of regulating oil and gas activities. These
activities were considered uses of state concern. To date, only a few parishes
of Louisiana's 19 coastal parishes have agreed to the state's regulatory role
and have gained approval of their local program. In addition, the Department
of Natural Resources has denied only a few applications for dredging in the
wetlands. Even today, permits allowing the dredging of access canals and flow
lines through the marsh are routinely approved.

As a backdrop to the rubber-stamp regulatory system of the Army Corps and
the DNR, until recently lines of communication between various state and federal
agencies with interests in the coast were restricted, and coordination was
practically non-existent. Even within DNR, conflicts occurred between regulation
and the revenue- produc i ng benefits of exploration and production. Communication
was so poor that as recently as last year, the Louisiana Department of Economic
Development was heavily recruiting the location of a seafood processing plant

348

Edmonson

whose fish product was currently under strict quotas by the Department of
Wildlife and Fisheries.

In 1982, in response to public outcry, the Louisiana state legislature
passed the state's first Coastal Environment Protection Trust Fund, which was
funded with $35 million, and a project priority list was submitted. None of
these projects was ever fully implemented because of heated scientific debate
over the proper way to preserve and protect barrier islands and wetland habitats.
In 1987, the fund was dissolved and was placed in the state's general fund to
help balance the ailing budget.

Meanwhile, the Corps was catching up on research on the benefits of wetland
and barrier system habitats. It proposed several wetland-nourishing freshwater
diversion projects off of the Mississippi River. None of these projects was
constructed, however, because of general apathy by area congressmen and the state
government. Now that the projects have received congressional authorization,
the state cannot meet the new requirements of local cost sharing.

While the state and federal effort stumbled along for nearly ten years,
a quiet storm was brewing down in the bayous.

DESIGNING THE LOCAL PROGRAM

In the early days of Coastal Zone Management, local governments and their
citizen advisory committees conducted the majority of technical research for use
in the development of both the state and local plans. This early research and
their knowledge of their local environment gave local governments and their
citizenry an edge on what was best for their specific situations. Therefore,
frustration grew over the slow and disjointed reactions of state and federal
governments. Because these same coastal parishes received millions of dollars
in royalties and taxes for oil and gas activities, many decided that if the
problems of relative sea level rise were to be solved, they would have to go it
alone, at least initially.

Terrebonne, the wealthiest parish, mounted the largest local effort. By
1980, Terrebonne funded and produced the state's first comprehensive
environmental assessment and land loss study. Terrebonne's early quest for
information helped spark scientific curiosity. Its research grant program helped
develop the state's excellent coastal and marine research centers. Efforts were
not always focused on research, however, as skirmishes with state and federal
agencies were frequent. In 1983, the parish organized a monumental citizen-
based attack against the Army Corps of Engineers, protesting the proposed
extension of the Atchafalaya River's east guide levee. No one could believe the
Corps would repeat the mistake that was made on the Mississippi River by
preventing the freshwater and nutrients of the Atchafalaya River from entering
Terrebonne as a result of the construction of the levee.

By 1984, Terrebonne Parish was fully aware of its problems and possessed
the knowledge to solve most of them. But it knew that the resources to retard

349

Economic and Financial Implications

the destruction of the delta were not available unless the state and federal
agencies were coordinated and properly funded. In the fall of 1984, Terrebonne
officially recognized relative sea level rise as a threat to Louisiana and its
people and developed a comprehensive approach to problem solving.

The key elements of the comprehensive approach are research, education and
public support, lobbying, funding, and construction.

Hundreds of research papers and studies have been completed under the
cooperation and coordination of local and state governments, the state
universities, and the private sector. Today, this research effort continues.
Armed with this research and the collective knowledge they represented, the
citizens of Terrebonne recognized any effort to combat problems of such magnitude
as coastal erosion, land subsidence, and sea level rise was going to be long-
term and expensive. To maintain such an effort, they also realized they needed
full public cooperation and support. In an effort to generate such cooperation,
the Parish embarked on a major educational program.

In 1983, the Parish government developed two slide shows on the Parish's
economy and the environment. These slide shows were distributed to civic
organizations, schools, and congressional offices. To supplement the slide
shows, the Parish developed three brochures for distribution to the general
public and the public school system. Billboard posters were designed to convey
the importance of preserving our barrier islands and marshes. Several of the
posters were periodically displayed on area billboards. A barrier island
foundation was organized to encourage and support the coordination of efforts
to protect and preserve the Parish and its inhabitants. Finally, the Parish
government, in cooperation with the Parish school board, developed and
implemented an eighth-grade curriculum dealing with the subjects of geology, the
environment, renewable and non-renewable resources, erosion problems, and
solutions. The intent was that by educating our youth, they would grow and live
within the Parish with a new sense of values for their environment and its
productive potential. The Parish also realized the first eighth graders educated
would be of voting age in ten years and might be instrumental in supporting a
Parish tax for preservation purposes.

Several years later, Lafourche Parish followed suit. Like Terrebonne, it
also developed brochures on the impending threats of sea level rise, and
developed its own seventh grade curriculum for implementation in the school
system. Today, both school boards continue to use the environmental curricula,
which have proven to'be very beneficial, not only to the students but to all of
the residents of the region.

By 1985, Terrebonne Parish locally funded and constructed the state's first
barrier island reconstruction project. The $850,000 project was designed on
natural coastal processes and consisted of rebuilding 35 acres of island by
reconstructing the foredunes, elevating the island, and planting natural
vegetation. To date, it has survived five hurricanes and is the state's most
successful and cost-effective island project.

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Edmonson

Next, Terrebonne realized that in order to receive the millions of dollars
required to correct its problems, a lobbying effort would have to be launched,
demanding that state government draft and subsequently pass legislation. In the
fall of 1986, the Coalition To Restore Coastal Louisiana was formed. The intent
of the Coalition was to fashion a broad-based, grass-roots support mechanism to
educate both the citizens and the politicians on the actions that would be
required to preserve our valuable wetlands system. Terrebonne Parish provided
a portion of the seed money necessary to allow the Coalition to develop, and in
January 1988 the Coalition was incorporated. The Coalition immediately began
working with key legislators and many friends of the coast to spearhead the
passage of two environmental bills- one to establish an administrative structure
to restore Louisiana's coastline, and the other to provide funding for the
restoration projects.

Although in 1984 we thought by educating our seventh and eighth graders
it would take ten years to win citizens' support for legislation and funding,
it in fact only took five years, and both bills were passed in 1989 by the
Louisiana legislature. Senate Bill 26 established the administrative structure
designed to enhance coordination and cooperation among the state's various
agencies. The bill created a task force of state and federal agency heads and
Governor's office appointees to oversee wetland restoration efforts. It also
created an executive assistant to the Governor who has the authority to
coordinate efforts among the various agencies. The Office of Coastal Restoration
and Management within the Department of Natural Resources will serve as the
primary agency responsible for implementing the state's coastal, vegetative,
wetlands, conservation, and restoration plan. Although the new law overcomes
the state's past history of conflicts over agency turf battles and conflicting
mission statements, the Louisiana Shore and Beach Preservation Association is
disappointed with the low priority given to measures for stabilizing the beaches
of the barrier islands. Efforts are currently under way to rectify this problem.

With the administrative structure in place, the next task was to secure
funding. Senate Bill 25, also passed by the Louisiana legislature in 1989,
submitted to the voters of Louisiana a constitutional amendment to create the
Wetlands Conservation and Restoration Fund. Revenues for the fund would come
from the state's mineral revenues.

On October 7, 1989, the citizens of Louisiana passed the constitutional
amendment. The Restoration Fund created by the amendment will derive its funds
from revenues received each fiscal year from the production and exploration of
minerals, severance taxes, royalty payments, and bonus payments on rentals after
previously dedicated allocations have been made. For the first year (1989), this
was to be between $5 million and $40 million. Annually thereafter, the Fund will
receive $10 million when the mineral revenues reach $600 million after
allocations, and another $10 million when the revenues reach $650 million. The
fund is not to exceed $40 million at any given time.

The final phase of the multi-pronged comprehensive approach to problem
solving involved construction activities. With the passage of Senate Bill 25,
the constitutional amendment, and the creation of the Wetland Conservation and

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Economic and Financial Implications

Restoration Fund, monies were in place to begin construction phases. Initially
these funds will be used as the local cost-sharing match for the U.S. Army Corps
of Engineers' freshwater diversion projects along the Mississippi River. Battle
lines have already been drawn, however, on the appropriate usefulness of this
expenditure. Many realize that the massive costs of these diversion projects
far outweigh the benefits derived. Although a small portion of the Fund will
be used for marsh management practices, many feel more emphasis should be placed
on barrier island stabilization projects.

CONCLUSION

In conclusion, the success of Louisiana's efforts was based on undertaking
strategic planning efforts aimed at problem solving. Under a strategic planning
process the following steps are followed. First compile a situation audit
(assemble the data base). Next, analyze strengths, weaknesses, opportunities,
and threats. Then develop action strategies to overcome weaknesses and threats
and to facilitate opportunities and strengths. Within this process, ultimate
success relied upon improved communications, mutual support, self help
coordination, research, education, and coordinated lobbying. If local citizenry
is reluctant to accept the consequences of sea level rise or fails to understand
the implications, religion can be a very helpful tool. Most religions of the
world have the stewardship of the earth's resources within their foundation.
Use churches, mosques, synagogues, and temples to express the importance of
stewardship.

Although south-central Louisiana's work has just begun, this effort has
instilled hope when just a few years ago there was no hope at all in addressing
the implications of sea level rise.

BIBLIOGRAPHY

Louisiana Tax Commission. 1989. Twenty-third Biennial Report, 1986 - 1987.
Baton Rouge, LA: Louisiana Tax Commission.

Penland, S., and R. Boyd. 1981. Shoreline changes on the Louisiana barrier
coast. Oceans 81:209-219.

Penland, et al. 1988. Relative Sea Level Rise and Delta-Plain Development in
the Terrebonne Parish Region. Baton Rouge, LA: Louisiana Geological Survey,
Coastal Geology Technical Report No. 4.

Wicker, et al. 1980. Environmental Characterization of Terrebonne Parish, 1955-
1978. Baton Rouge, LA: Coastal Environments, Inc.

352

TOWARD AN ANALYSIS OF POLICY, TIMING, AND THE
VALUE OF INFORMATION IN THE FACE OF
UNCERTAIN GREENHOUSE-INDUCED SEA LEVEL RISE

GARY W. YOHE

Professor of Economics Guest Investigator
Department of Econmics Marine Policy Center
Wesleyan University Woods Hole Oceanographic
Middeltown, CT 06457 Institution
Woods Hole, MA 02543

ABSTRACT

The paper has three thrusts. In the first, a methodology is constructed
by which researchers can (1) evaluate the relative economic efficiency of various
responses to some climate change effect based upon the best current information,
(2) anticipate the most appropriate timing of those responses, given current
information, and (3) assess the value of future information, which might alter
both their timing and their relative social value. The second focus will
highlight the preliminary results of applying the methodology to anticipating
the decision of how best, if at all, to protect Long Beach Island, New Jersey.
The application will rest, in part, on economic vulnerability data collected as
part of a national sample. A third distinct section records comparable data from
other sites taken from that sample. Concluding remarks emphasize the general
insights to be drawn from the methodology and its application to Long Beach as
well as the data requirements for more widespread application. Of particular
note, here, is the need to move past economic vulnerability to opportunity cost
in producing the requisite measure of the benefits of protection.

'Support for both the methodology and its application to sea level rise
was provided by EPA Cooperative Agreement (CR-814927-01-2); counsel offered in
that effort by Jim Titus at EPA as well as Jim Broadus and Andrew Solow at
Woods Hole Oceangraphic Institution is greatly appreciated. So, too, are the
contributions of colleagues in the Precursor Program for Resource Analysis
into the Effects of Climate Change sponsored by the Department of Energy:
Robert Cushman at Oak Ridge National Laboratory; Jae Edmonds, Albert
Liebetrau, and Michael Scott at Pacific Northwest Laboratory; Pierre Crosson,
William Easterling, and Norman Rosenberg at Resources for the Future; and
Thomas Malone at Sigma Xi. Remaining errors are, of course, mine.

353

Economic and Financial Implications

The ef fects of greenhouse warming are likely to be widespread, but our
current understanding of their ultimate social, economic, and political impacts
is clouded with enormous uncertainty. There is, for example, a wide range of
estimates for greenhouse- induced sea level rise reported by various researchers
over the past five years. In light of this disagreement, the U.S. EPA (U.S. EPA,
1988) puts our best guess for greenhouse- induced sea level rise through the year
2100 somewhere between 50 and 150 centimeters. Researcher De Q. Robin (1987)
expands that range, expecting anywhere between 20 and 165 centimeters. Schneider
and Rosenburg (1989) are more conservative, suggesting a range of 10 to 100
centimeters, but others still contend that a 2- to 4-meter rise cannot be ruled
out (see Titus, 1989). Thus, the fundamental question in responding to sea level
rise and to other dimensions of global climate change is one of determining if
any response should be undertaken or even anticipated, given that we are so
unsure of exactly what the future might hold -- a question of very long-term
decision making and anticipation under conditions of enormous uncertainty for
which we currently "have (no) workable guidelines" (White, 1989).

Response to climate change could be averting or adaptive (see Lashof and
Tirpak, 1989). Evaluation of the efficacy of any averting response, even though
it would have to be imposed globally, should certainly be based upon some measure
of regional effects scattered around the globe, and should certainly include the
potential of complementary adaptive response. Adaptive response would most
likely be enacted on a local or regional level, so perhaps even more detailed
measures of region-specific effects would be required. In either case, analysis
of possible reaction to the threat of climate change must be soundly based on
an understanding of local and regional consequences (see McCracken et al., 1989).

Returning to sea level rise, the relative merits of various adaptive
responses must be evaluated on the basis of the local economic and social
ramifications across the full range of possible global sea level scenarios.
They should, therefore, depend upon a vector of site-specific characteristics:
the geographical distribution of developed and undeveloped property, the value
of that property, the potential for moving and/or protecting that property, the
underlying trends in natural 'subsidence, and so on. They should also depend upon
variables whose influence extends well beyond the boundaries of the specific site
-- e.g., scientific parameters that relate concentrations to global warming,
warming to climate change, and climate change to land-based ice melt and the
thermal expansion of the oceans. Expressed most efficiently, the local
reflection of global sea level rise should be summarized in terms of time-
dependent and scenario-contingent subjective distributions of potential economic
cost based upon our best current understanding of the underlying uncertainties
and correlations.

It should be clear, however, that restricting attention to current
understanding will reveal only part of the story. We will certainly learn more
about what the future holds as we move forward in time, so a second, derivative
question arises: one of determining the value of future information and its
effect on the relative efficacy of our response options. It could be

354

Yohe

"orthogonal" (providing indirect information about a critical state variable by
improving our understanding of the likely trajectories of the underlying, driving
variables) or it could be "Bayesian" (providing increased understanding of a
critical state variable by directly monitoring its trajectory). In either case,
it should be expected that the value of such information should be different for
different anticipated policies, and its assimilation could easily alter relative
efficiency within the entire set of possible options.

Therefore, a thorough analysis of the response anticipation problem requires
a methodology by which we can accomplish the following:

� produce a ranking of alternative response options, given current
information;

� suggest the anticipated timing of those options, given current
information;

� suggest how the ranking and timing results based on current information
might change in the future as we learn more about what might be
happening;

� evaluate the economic value of new information for each policy;

� evaluate how new information might alter the ranking and timing of
potential responses; and

� suggest directions for which the results of future scientific and social
scientific research might be most valuable.

Only by making progress in handling these tasks will we be able to begin
to answer more fundamental questions of timing and planning. Can we, for
example, wait to respond to climate change, or must we act now? If we choose
to wait, what should we do in the meantime? Should we plan to deal with the
extreme possibilities of climate change, or can we focus on responding to our
best guess at what the future will bring? Will adaptive response be endogenous
to the system, or should we anticipate a need to make conscious decisions at some
point in time?

A FORMAL CHARACTERIZATION OF THE RESPONSE PROBLEM

Let the future trajectory of some vector of state variables yt = yt(et) be
distributed at each point in time according to fjet], with et representing a
vector of random variables that produce long-term stochastic effects on yt. Let
the cost associated over time with yt be reflected by Ct = Ctfyjej). Any action
or sequence of actions aJyt(9J] taken in the future in response to yt will
involve some stream of expenses ot(at[yJej]) and achieve a corresponding stream
of benefits equal to the cost avoided at any point in time:

355

Economic and Financial Implications
r,(yJeJ;aJyJeJ]) = C,fy,(e,))-C,(y,(e,)Ia,[y,(e,)]).

The expected value of the present value of some (or series of) responses
spread into the future, computed at time to with a social discount rate p, is
then simply

E(PV[at;ft(et)]) = f f [r(yt;at)-o{a,)]ft(eJd9t e-fltdt. (1)
to t

E(PV[at]) should, in principle, be the appropriate statistic with which (1) to
rank potential responses to various possible trajectories for yt and (2) to
evaluate the best timing of those responses given the best information currently
available.

A RANKING PROCEDURE

The expression recorded in Equation 1 is, of course, extremely general --
almost so general that it is useful only as a symbolic representation of the
correct objective function. Thinking about the structure of most responses can,
fortunately, produce a more illuminating formulation. To see how, recall that
we are considering strategies for future responses armed only with a collection
of subjective distributions of the state variables yt and an imperfect
understanding of how the underlying 'random variables et will drive them into the
future. Many responses will, however, be triggered in practice only when certain
state variables cross specific critical thresholds. These thresholds will be
crossed at time uncertain in the future, but many can be identified even now.
In the case of sea level rise, the threshold for building a new bulkhead or for
moving a certain structure might be an increase in the mean spring high tide of
45 cm (or 55 cm or 100 cm, depending upon the site). It makes sense, as a
result, to focus on the orthogonal conditional distribution g,,(t) of timing for
crossing some given threshold y..

Returning now to the formal problem, consider a univariate vector of state
variables, and let the structure of the planning process suggest a partitioning
of the range of go(t) into intervals( I', I. I'n) . There exists a corresponding
partitioning of the range of sequences of the e,, which bring yt across the
threshold within the specified intervals I',. Let that partitioning be given by
(,ev---,,9J. The partitioned expected present value respresented in Equation 1
can then be written

00
EP{PV[,a,, 1na,;f,(eJ]) f E[r(Y,;ia,)-o(ia,)]f,(et)det)e-Ptdt, (2)
to iet

356

Yohe

where a, represents the response that would be anticipated in partition 8,. For
perfectly endogenous responses, there is no difference between Equations 2 and
1; the partitions simply produce a distinction with no content. For other
responses whose timing and magnitude are critically dependent upon speed and
momentum with which the threshold is reached and passed, however, there is a
potentially significant distinction.

To see why, let some response be generically defined and represented by
aV Implicit in the definition of at are issues of both timing and scope, so
ia, can be thought to represent the best configuration of action a, that can
currently be anticipated, given that yt is expected to cross the threshold in
interval Iti. If we are forced to anticipate enacting one response strategy
based on current information, then we should rank each according to the
discounted values of expected net welfare -- i.e., the various a*, should be
ranked according to

Ep(ia*tJf,(eJ) = Ep(PV[ia*t,...,ia*t;f,(et)]); (2a)

Response ia*t.such that
Ep(,a*t*lft(et)) @ Ep(ja*tJfJ9J) for all j (2b)

is thus the best single option of time and scope that can be anticipated, given
current information. Note, as well, that Equation 2b can define the best timing
of a particular response because the various iat considered can represent
anticipating the initiation of that response at different times.

THE VALUE OF DISCRIMINATING FUTURE INFORMATION

What of future information that allows differentiation across the range of
timing intervals prior to the need to begin any response? Equation 2 provides
an easy means of sorting out both its effect on the best anticipated response
and its resulting economic value. Suppose, for example, future research held
out the possibility of uncovering information that would allow us to tell, prior
to acting, whether the threshold would be crossed in a subset of early intervals
11 = (1It,...,rIt) or in its complement set of late intervals I' = ( rn,1 It . . . . I n It) .
There is, of course, an equivalent partitioning of the range of et. Repeating the
process just described for restricted sets of intervals V and P would then yield
two best choices: a*t for V and ha*t for 1'. The expected present value of
choosing response strategies contingent upon discovering either Vor I h would
then be

Ep(l';Ihlft(et)) = Ep(PV[1at=,a%; ... ;.at=la't; (M+,)at=ha*t; ;nat=ha'tl ); (3)

357

Economic and Financial Implications

and the value of the information that provided the ability to discriminate would
be

Ep(I';IhJft(eJ) - Ep(,a*tJft(et)) @ 0 (4)

It is, of course, possible that a*t* = a*t = ha* in which case the difference
recorded in Equation 4 is exactly zer@; but strict"inequality should be expected
whenever, as should be the rule, a*t* 3o a*t Y ha%.

Information that discriminates across the range of possible futures can
have value, and it can alter the timing and character of any response that might
be anticipated. Constructing a catalog of the best response strategies for a
collection of possible distinguishable partitions of sets of intervals
(it . . . . . .I tn) would provide insight into the sensitivity of anticipated responses',
including their timing and their scope, to this sort of new information.
Recording, as well, the value of the information that informs those strategies
would meanwhile indicate areas of research that would be most fruitful.

THE VALUE OF BAYESIAN LEARNING

The new information considered in the previous section was essentially
orthogonal -- performing a discriminating function without influencing the
density function ft(et). Other types of new information are, of course, possible.
A Bayesian learning process could, for example, be envisioned moving along any
of the trajectories of yt that lead to crossing the threshold during some
corresponding interval Jt. Such a process would not influence our current best
view of the range and relative likelihoods of threshold intervals, but it would
alter. future subjective distributions of those intervals. This is clearly
information of a different character, but the problem of estimating its value
can, in the present framework, be thought of as one of estimating the'value of
discriminating information that is not perfectly accurate. The key is that
future decisions will be based on updated information, and it is those decisions
based on future information that must be evaluated, given what we know now.
To model these decisions, let pt(et;t,;e kJ represent the posterior
distribution of et that would be derived in period t, > %, given interim
experience consistent with ete ekt . Evaluation of any response sequence at would
then, in period t,, be based upon EI(katl pt (8t; t' ; ekt) )for any ek, . Best choices kit
would then be characterized by

EP(k't Ipt(et; tj ; ekt) ) > EP(katlpt(ot;tl;e kt) for al 1 at

and would define the anticipated response, its timing, and its scope. The
current view of the expected social value of the kit should, therefore, include

358

Yohe

their anticipated expected social value, given experiences consistent with e,e
ek, but weighted by current expectations of the relative likelihoods of the 8 k t;
i.e.,
jp(05t) @ 1 fk ft(et)det Ep(k'tl pt(et;tj;Ik)) (5)
9 t

should be used to evaluate the present value of using future Bayesian information
to inform response decisions.

Notice that the composite expected present value defined in Equation 5
provides direct access to a measure of the economic value of Bayesian
information. Compared to Section Ivariablel case with no extra information in
which a*t* was selected as the best single option that could be anticipated with
curre.nt information. The value of Bayesian information is Simply Jp(kfid -
Ep(,a*tI fjej). It should be non-negative, of course, because a,* was a choice in
the decision process characterized in Equation 5. It could be zero, though, if
the Bayesian process produced too little information, because the posterior
distributions would then nearly match ft(et) and the kat would all match ia*t*. It
could also be zero if the cost and benefit schedules implicit in the definition
of both BEpf-) and Ej-) were linear.

Generat'ing catalogs of the sort suggested at the end of Section III should
be able to produce the same sort of sensitivity and value insight for anticipated
Bayesian learning as it did for orthogonal learning. Notice that the structure
created in here should also be applicable to new orthogonal information that is
not perfectly discriminating. In the former instance, we glean some insight into
the value of waiting (and learning while we wait); in the latter, we still gain
some understanding of where we should be devoting research efforts in the
meantime.

APPLICATION TO PROTECTING LONG BEACH ISLAND

Long Beach Island, a barrier island lying off the shore of New Jersey, is
approximately 23 miles long and varies in width from roughly 1,000 feet to
slightly more than 3,200 feet. Except for dunes on the ocean side, almost all
of the island lies within 10 feet of sea level. It is, nonetheless, heavily
developed, with total property value generally put in the neighborhood of $2
billion (1989$). Data have been developed reflecting both the economic
vulnerability of the island in the absence of any protection (Yohe, 1989) and
the cost of.employing three different protection strategies (Weggel, 1989).

This section applies the analytical tools developed above to these data to
evaluate the relative efficacy of two of the options investigated by the EPA:
(1) raising the island as the sea level rises (an endogenous response), and (2)
building a dike and associated infrastructure when the sea level rise crosses

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Economic and Financial Implications

a predetermined threshold (a conscious response requiring anticipation and
preparation). The rate of. sea level rise will be taken to be the critical,
random-state variable. The value of orthogonal and Bayesian information will
be considered using a distribution of possible sea level rise scenarios drawn
from current divergent opinion.

The Data

Table 1 records the total economic vulnerability data reported in Yohe
(1989). Tax maps were employed to determine the current value of property
(including land and structure) that would lie below the spring mean high tide
for various levels of sea level rise. Property that would be in jeopardy because
of beach erosion was also included, so the statistics registered in Table 1
reflect a measure of what, as the island now stands, would be "in the way" of
rising seawater and its derivative effects. They will, for present purposes,
also be taken as a measure of potential economic costs attributable to sea level
rise. Of course this procedure will be a source of error, since it ignores the
possibility of a wide range of complications: further economic development prior
to inundation, property depreciation in anticipation of inundation, etc. The
translation of vulnerability data to cost data has not yet been accomplished,
however, so vulnerability will simply be employed here as an illustrative "first
cut" at potential cost.

Weggel and his colleagues (1989) have produced estimates of the costs
involved in protecting Long Beach Island. Raising the island in place given
observed sea level rise has three sources of cost: fill (sand available at $6
per cubic yard along a scenario. that sets greenhouse- induced sea level rise
equal to a 200-cm rise in the year 2100), raising structures (at $5,000 per
structure to accommodate the higher ground), and replacing roadways (which must
lie on top of the new higher ground). Since these costs are correlated

Table 1. Economic Vulnerability for Long Beach Island

Sea Level Rise Incremental Vulnerability Total Vulnerability
(cm) ($ million) ($ million)

0 - 15 15 15
15 - 30 40 55
30 - 45 225 270
45 - 60 192 462
60 - 90 381 843
90 - 120 705 1548
120 - 180 385 1932

Source: Yohe (1989)

360

Yohe

directly with sea level rise, producing time series of costs for scenarios other
than the one that produces 200 cm over 115 years is a simple matter of algebra.
The only wrinkle employed in the translation involves the price of fill. A
unitary short-run price elasticity of supply was employed, but only for more
rapid scenarios. The price of fill would rise if demanded more quickly than
anticipated along the 200-cm baseline but would not fall if demanded more slowly
(i.e., $6 represents a long- run competitive price equal to a minimum sustainable
average cost).

The second option considered here proposes (1) building a dike around the
island when sea level rise from any source reaches 43 cm and (2) operating an
interior drainage system from that time on. The dike itself was estimated to
cost $285 million. Some small cost derived from raising existing bulkheads
would be incurred before the dike were brought on line, and expenditures equaling
$2.5 million would be required each year to maintain and operate the drainage
system. Any scenario of sea level rise would, in this case, imply a planned date
for constructing the dike that could be correct, early, or late. If correct,
then the stream of costs would be well defined by the Weggel estimates. If the
planned date turned out to be early, then policy makers would be prepared early,
and could simply wait to build the dike until it became necessary. If the
planned date turned out to be late, however, then inundation would occur before
the construction of the dike and the drainage system. It was assumed that
completion of the dike it would require at least 5 years from the recognition
of immediate need, unless completion was originally planned in the interim.

Sea Level Rise Scenarios

A distribution of projected sea level rise attributable to greenhouse
warming through the year 2100 was derived from the range of expert opinion
reported in the introduction .2 A log-normal distribution fit the divergence of
opinion well, exhibiting a mean of 4.55 and a standard error of 0.88. The one
standard error range around the mean increase of 94 cm was therefore taken to
be 39 cm on the low side and 227 cm on the high side. A five-cell discrete
equivalence of this distribution is provided in Section I of Table 2. For the
probability values shown there, the second row shows the time coefficient a, for
each scenario, which drives total sea level rise according to the EPA functional
representation:
SLi(t) = .4(t-1986) + aj(t-1986 )2 (6)

The first term in Equation 6 reflects local subsidence for Long Beach Island of
0.4 centimeters per year, while the second term reflects greenhouse- induced sea

2See Nordhaus and Yohe (1983) for a discussion of this technique. It
assumes implicitly that every expert estimate is sample point derived from the
true distribution; as should be expected, it has been shown, at least in one
case, that it tends to underestimate true variability [see Yohe (1987)].

361

Economic and Financia7 Imp7ications

level rise. Table 2 also indicates the year during which the 43-cm threshold
for the dike would be passed.

Raising the Island

Raising the island would be a contingency response, defined by Weggel as
one of raising structures, raising roads, and adding fill beneath both as needed
to keep dry land approximately 40 cm higher than the mean spring high tide.
Starting when total sea level rise from 1986 reaches 13 cm, Weggel et al.
estimate the volume of sand (in cubic yards) required in year t along a 200-cm
greenhouse-induced scenario to be
V200M = 73534 + 5273(t-1986) + .427(t-1985 )2

The 200-cm scenario is, meanwhile, defined by

SL2110(t) = .4(t-1986) + a,(t-1986 )2,

where a, = .01424. The volume requirement along any scenario j is therefore
Vj(t) = 73534 + 5273(ai/ab) 112(t_ 1986) + .427(aj/*b) (t-1986 )2

Price times volume then provides the appropriate estimate of the cost of fill
as a function of time along any scenario. Similar manipulation of the Weggel
estimates of the cost of raising structures and replacing roads (in $ million)
produces:
csj(t) = 13.65(a'/*b) 112 + .01(aab) (t-1986)
CTj(t) = 2.8j+ .133(aj/ab) 1/2(t_ 1986),

respectively. The Cjyjej function required in Equation 1 is simply the sum
of these three cost components for the specified scenarios.

Representing the benefit achieved by this action at any time along any
scenario by the economic value of property preserved by preventing inundation,
its net present value is easily computed, given C,(--). The Section II of Table
2 records these values for the five scenarios identified in Section I for a 3%
social rate of discount. The final entry notes the expected net present value
computed according to Equation 1. Raising the island is found to be an
economically viable option that could be undertaken, depending upon stress
exerted on the public budget constraint by other claims to public resources.

Constructing a Dike and Drainage System

Protecting Long Beach Island by constructing a dike and its requisite
drainage system would require considerable prior planning and development, a
protracted period of construction, a commitment to continuous maintenance after
construction, and a future stream of enormous expenditure of public revenues.
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Yohe

Table 2. Expected Present Value of Raising the Island
or Constructing a Dike and Drainage System

Scenarios
--------------------------------------- (7)
Policy (2) (3) (4) (5) (6) Expected
Description A B C D E Present Value

I. Scenario
Description:

Probability 0.1 0.2 0.4 0.2 0.1 n/a
Coefficient .00144 .00318 .00718 .01595 .03539 n/a
Threshold 2069 2055 2039 2026 2015 n/a

II. Raising the
Island 13.0 32.5 129.7 252.6 355.6 145.8

III. Anticipating
a Dike in:

2015 37.4 67.1 157.0 309.2 463.0 188.1
2026 38.7 68.9 158.9 311.9 88.8 152.5
2039 40.8 71.0 160.7 117.6 88.8 115.0
2055 42.0 72.6 52.7 117.6 88.8 72.2
2069 43.4 14.6 52.7 117.6 88.8 60.8

It would require, in short, a wide margin of preparation time. Any current
consideration of the economic value of such an option must, therefore, be based
upon an anticipation of exactly when a specified threshold of sea level rise will
be crossed.

Section I of Table 2 shows the years during which the threshold for Long
Beach Island, calculated by Weggel to be roughly 43 cm, would be achieved along
five representative scenarios of sea level rise. Since the scenarios were
selected to reflect a current subjective distribution of potential sea level
trajectories, these years can be viewed as representing the associated
distribution of dates at which construction of the dike system must be completed
to adequately protect the island. They define, as a result, five representative
responses that are differentiated solely on the basis of timing and that span
the range suggested by the current subjective distribution of sea level rise.

Columns (2) through (6) in Section III of Table 2 record, for each scenario,
the discounted net benefit of anticipating the completion of the dike system for
each of the dates listed in Table 2. The diagonal, therefore, shows the maximum
discounted benefit for correct timing along each scenario. Figures below the

363

Economic and Financial Implications

diagonal show the discounted net benefits that should be expected if the critical
threshold were breached earlier than anticipated. They are all the same because
the dike would be hurriedly completed in the same time frame along each scenario
as soon as the threshold passed. Figures above the diagonal similarly reflect
the discounted net benefit of being ready too early.

The expected discounted net benefit for each anticipated date of completion,
computed from columns 2 through 6 according to Equation 2a, is provided in the
final column. These are estimates currently available in the absence of any
further information. Ranging from $188.11 (million) for anticipating completion
of the dike system in the year 2015 down to $60.77 (million) for planning
completion in 2069, they clearly show a marked dominance for planning to take
early action. Building in anticipation of the extreme case depicted in Scenario
E even dominates the endogenous island-raising response examined in Subsection
C (by 22%). The insurance of preparing for the early completion of the dike
system, even at the expense of being prepared too early and even given the
subsequent expense of actually constructing the dike, is less costly in terms
of expected, discounted expenditure than the continuous process of raising the
island year in and year out. This relative ranking persists even when a mean
preserving 50% contraction in the variance of the lognormal distribution of
greenhouse- induced sea level rise through the year 2100 is imposed; it is a
robust result.

The Value of.Orthogonal Information

Table 3 shows the results of contemplating the discovery of some new
information that will, in the future, allow policy makers to distinguish between
subsets of the five threshold scenarios listed in Table 2. Each section of the.
table presents results for a different partitioning of the five-cell discrete'
distribution of sea level scenarios and records the expected discounted value
of anticipating the completion of the dike system at the threshold time
indicated, given that a scenario within the partition occurs. In other words,
each entry shows the results of applying Equation 2a to a limited range of.
possible scenarios.

Before reviewing the content of Table 3, it is perhaps prudent to picture
exactly what sort of information might accomplish the partitioning modeled there.
Better understanding of the thermal expansion of the ocean, better estimation
of the correlation between concentrations of various gases and the Earth's
radiation budget, progress in identifying the "greenhouse fingerprint,"' etc.,
could all be envisioned as opportunities for new insight that would allow us to
limit the range of possible sea level futures that we need to consider. That
is, each has the potential to rule out certain scenarios in the future which,
given today's information, are still plausible. We have no idea whether such
information is forthcoming, so there is no reason to adjust the. current
subjective distribution of sea level scenarios. We are, quite simply,
investigating how much it would be worth to us now, if it were to appear sometime
prior to the need for any response.

The "Best Year" column in Table 3 shows the best contingent choices for
anticipating the completion of the, dike system for four partitions; Compared

364

Yohe

with the uninformed expected present value of $188.11 (million) associated with
planning completion by 2015, none appears to be much of an improvement. Computed
according to Equation 4, the most valuable partition distinguishes between early
and late scenarios at roughly the 70th percentile, returning an expected
discounted value of ($190.71 - $188.11) = $2.6 (million). Given the value of
perfect discrimination $191.82 (million), though, there was not much room for
improvement to begin with.

That is not, however, the entire story. Notice that the expected present
value of planning the construction of the dike system changes only slightly in
the 25-year period between 2015 and 2039. Information that distinguishes early
from late around the 70th percentile could, therefore, ease some of the budgetary
pressures that might otherwise be felt by the federal government if its share
of the expense had to be committed within a more limited time frame. Devoting
some effort to research that might accomplish even this sort of crude division
in the potential range of sea level outcomes could, therefore, have some indirect
payoff beyond its $2.6 million contribution to expected net benefit. Finally,
note that Table 3 suggests a greater payoff to research designed to distinguish
rapid sea level rise from slow sea level rise than to research designed to
identify the extremes.

The Value of Bayesian Information

The year 2015 is the first threshold year identified above, suggesting a
potential waiting period of roughly 25 years during which Bayesian learning
might better inform potential response decisions. Steve Schneider has suggested
that convergence in our view of the complex effects of climate change cannot be
expected over the next two or three decades (Rosenburg and Schneider, 1989).
In modeling a Bayesian learning process along any of the five sea level scenarios
identified in Table 2, it therefore seems reasonable to assume that experience
over the next 30 years can be viewed as supporting observations drawn from a
lognormal distribution exhibiting the same variance as today's. Since
climatologists look at 30-year intervals to assess and define changes in climate,
we can also expect at most the equivalent of one such observation. Representing
the current view of the distribution of the natural logarithm of sea level in
the year 2100 by ln(SL(2100)) - N(m,,,o,.), the result of 30 years of movement
along scenario k yielding an estimated x, = ln(SL,(2100)) should therefore be a
new, contingent distribution ln(SL(2100))k N(Mk I O'k) with Mk = 0.5(m. + Xk) and
2 2 2
a k = (a0or .)/ ( 020+020) 0 . 5a2. If the x, are taken to equal the natural log of
the 2100 values indicated in Table 2 and .7. = 0.88, then each of the five
scenarios must be assigned different discrete probability values consistent with
N(mkt'Tk) and contingent upon which scenario defined the 30-year experience from
1986 through 2015.

Table 4 indicates the resulting expected discount values of all six options
(raising the island and constructing a dike during the five alternative years)
contingent upon the learning that would occur in the first 30 years along each
scenario in columns 2 through 6. Each has been computed according to Equation
5a. The final column records the current view of their expected discounted net
benefit based on Equation 5b. The figures recorded in column 7 of Table 4
reflect, when matched against the comparable figures in Table 2, our best idea

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Economic and Financial Implications

Table 3. Expected Present Values for Constructing a Dike-
Differentiating Information

Anticipated Year for Completing the Dike Expected
---------------------------------------- Best Present
2015 2026 2039 2055 2069 Year Value

(A) from (B,C,D,E): $188.7
(A) 37.4 38.7 40.8 42.0 43.4 2069
(B,C,D,E) 204.9 165.1 123.2 75.6 62.7 2015

(A,B) from (C,D,E): $189.7
(A,B) 57.2 58.9 60.9 62.4 24.2 2055
(C,D,E) 244.2 192.6 138.1 76.4 76.4 2015

(D,E) from (A,B,C): $190.7
(A,B,C) 114.2 116.0 117.9 56.9 40.5 2039
(D,E) 360.5 237.5 108.0 108.0 108.0 2015

(E) from (A,B,C,D): $189.9
(A,B,C,D) 157.6 159.5 117.9 70.4 57.7 2026
(E) 463.0 88.8 88.8 88.8 88.8 2015

Complete 43.4 72.6 160.7 311.9 463.0 exact $191.8

Table 4. Expected Present Value of Response Options
After Bayesian Learning

Scenarios
(1) ---------------------------------------- (7)
Policy (2) (3) (4) (5) (6) Expected
Description A B C D E Present Value

I. Raising the
Island 64.5 99.1 138.4 195.5 249.4 145.8

II. Anticipating
a Dike in:

2015 96.7 135.5 175.7 248.3 317.9 188.5
2026 90.8 125.7 150.5 184.8 173.2 152.7
2039 79.3 98.5 125.5 115.5 109.6 115.2
2055 60.1 69.1 65.4 85.6 90.4 72.4
2069 41.2 47.9 57.4 76.9 86.3 60.9

366

Yohe

of how much Bayesian learning would be worth for each policy, given our current
subjective distribution across the trajectories that will be doing the "Bayesian
teaching." The differences representing that value, defined by Equation 5c, are
small; but that again is a function of both the effective contingency response
that was assumed when the dike was anticipated too early or too late and the
linearity of the resulting net benefit schedule. The real news buried in Table
4 can be uncovered by noticing that the variation in expected net benefit shown
across the rows in columns 2 through 6 is much smaller than the corresponding
variation in net benefit of the uninformed decisions of Table 2. An objective
function displaying any sort of risk aversion would therefore applaud the results
of the Bayesian process.

ECONOMIC VULNERABILITY ELSEWHERE AROUND THE U.S. COASTLINE

Coastal sampling by Park et al. (1989) has resulted in computer-based
mapping capability within which the inundation effects of various sea level rise
scenarios can be uncovered. Each site in the Park sample is partitioned into
square grid quadrants measuring 500 meters (sometimes 250 meters) on each side.
A computer run for any site provides, therefore, quadrant-specific effects in
5-year intervals for each scenario, defined not only by an assumed contribution
in sea level rise from greenhouse warming (50 cm, 100 cm, etc., through 300 cm),
but also by the underlying rate of natural subsidence (recall Equation 6).

Figure 1 shows, as an illustration, the computer maps for Charleston, South
Carolina. Panel A depicts the area in its current configuration, while Panel

8 0 0 1") SMIARLE. 80 00-1 SMIARLE.
. . ..... ...... ........ ...

0
CA, 0:: 1:.: 4A
0
(A

S 1 -1:: r-.s- 1.1

... ... ...........
. .. ........

Legend

PANEL A 1985 PANEL B 2100 (200cm)

Figure 1. Computer map of Charleston, South Carolina (U.S) showing (A) current
configuration and (B) configuration with a 200-cm sea level rise.

367

Economic and Financia7 Imp7ications

Table 5. Economic Vulnerability" and Wetland Los Sb
for Selected Sample Sites

Sitec 0-15 15-30 30-45 45-60 60-90 90-120 120-180 180-240

TXPORTLA (3mm)
Econ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.2
Wetland 0 0 0 0 0 0 0 0

TXPALACI (3mm)
Econ 0.0 0.0 0.0 0.0 1.3 0.0 0.0 0.0
Wetland 10 80 0 0 5 2 3** 0

LAGRANDC (8mm)
Econ 0.0 1.4 1.4 4.1 5.4 5.4 1.4** 0.0
Wetland 0 5 10 10 5 10 60** 0.0

LABARATA (9mm)
Econ 6.1 6.1 9.2 6.1 6.1 6.1 18.4 3.1**
Wetland 0 30 5 5 5 5 40 10**

MSPASSCH (Imm)
Econ .1.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Wetland 40 60** 0 0 0 0 0 0

FLSTJOSE (1mm)
Econ 0.0 0.0 0.0 0.0 0.0 0.0 1.6 4.8
Wetland none

FLPORTRI (1mm)
Econ 26.3 0.0 0.0 0.0 0.0 26.1 131 183
Wetland add add 10 60 5 25** 0 0

FLMIAMI (1mm)
Econ 148 295 592 811 1260 1770 7530 4130
Wetland none

FLSTAUGU (1mm)
Econ 2.5 1.1 2.5 15.3 16.5 5.0 24.2 24.5
Wetland 0 5 5 10 80** 0 0 0

STCHARLE (2mm)
Econ 26.1 34.8 8.7 8.7 34.9 78.6 39.1 65.6
Wetland 10 5 5 75 5** 0 0 0

NCLONGBA (Imm)
Econ 0.0 1.1 3.4 7.9 0.0 6.7 2.3 1.1
Wetland 0 10 20 65 5** 0 0 0
Notes: 6 In millions of dollars (1089). In percent of current wetlands.
cLocal subsidence recorded in (parentheses). Totally inundated.

368

Yohe

B shows the effect of 200-cm greenhouse- induced sea level rise superimposed
through the year 2100 upon a 0.2-cm per year natural subsidence. Economic
vulnerability, the current value of property which might be in the way of the
rising sea, is then accessible for each site from a procedure that computes the
average property value for each affected quadrant from tax maps and/or housing
and business census data. Table 5 registers the resulting data for a subsample
of the Park sites; Table 6 shows our nationwide estimates.

Table 6. National Cumulative Economic Vulnerability
to Sea Level Rise ($ billions)

Sea level rise 25th percentile Best estimate 75th percentile

50 cm 78.4 133.2 188.1

100 cm 165.8 308.7 451.6

200 cm 411.3 909.4 1407.6

CONCLUDING REMARKS

The problem of analyzing the economic value of potential responses to the
effects of global climate change is a problem that lies at the heart of decision
making under enormous long-term uncertainty. The methodology outlined in
Sections I through IV is advanced as a first step in confronting that problem.
It appeals to well-established economc tools to provide a means of organizing
onels thoughts in face of uncertainty, taking into account not only what we know
now but also what we might know in the future, and how we might, in the normal
course of events, react to that growing base of knowledge.

Only two new wrinkles in existing theory were employed. It was, first of
all, noted that the usual representation of uncertainty with subjective
distributions of future state variables at some point in time can, in many cases,
be replaced profitably in our thinking by the corresponding orthogonal
distributions of time when certain specific threshold values in those state
variables might be crossed. In that context, one can investigate the best
anticipated timing of some potential response, given the current subjective view
of the future, by taking advantage of the second wrinkle: defining a set of
derivative responses differentiated only by the time in which they would be
enacted. The best anticipated response then defines the best anticipated timing.

The application of the methodology to Long Beach Island also provided some
general insight. To the extent that communities can correct any error in
anticipating exactly when a given response might be required, new information
that can differentiate future states of nature prior to the need to respond will
be less or more valuable. That point notwithstanding, however, it is quite

369

Economic and Financial Implications

possible that the best anticipated response might be to guard against the
potential effects of scenarios at the extremes of current subjective
distributions. If the cost of being prepared too early is small, then planning
as if the future will unfold showing the maximum rate of sea level rise is the
best choice.

Finally, the notion that communities will learn about the future as it is
revealed should also be considered. This sort of Bayesian learning may provide
more or less extra in net expected benefit, depending upon the communities'
abilities to correct for errors in anticipation. Nevertheless', it can always
be expected to reduce the variance of possible futures at the time of actually
initiating a response. Any degree of risk aversion in the evaluation function
will, as a result, welcome the opportunity for such learning.

BIBLIOGRAPHY

Armstrong, J. , and R. Denuyl . 1977. An i nvestment dec i s i on model for shoreline
protection and management. Coastal Zone Management Journal 3:

Barth, M., and J. Titus, eds. 1984. Greenhouse Effect-and Sea Level Rise.
New York: Van Nostrand Reinhold.

Cyert, R., M. DeGroot, and C. Holt. 1978. Sequential investment decisions with
Bayesian learning. Management Science 24:
Dean, P., et al. 1987. Responding to changes in sea level. National Research
Council. Washington, DC: National Academy Press.

De Q. Robin, G. 1987. Projecting the rise in sea level caused by warming of
the atmosphere. In: The Greenhouse Effect, Climatic Change, and Ecosystems,
SCOPE 29. Bolin, et al., eds.

Hekstra, G. 1989. Sea level rise: regional consequences and responses. In:
Greenhouse Warming: Abatement and Adaptation. N. Rosenberg et al., eds.
Washington, DC: Resources for the Future.

Hekstra, A. 1986. Future global warming and sea level rise. In: Iceland
Coastal and River Symposium. G. Sigbjarnarson, ed.

Lashof, D., and D. Tirpak. 1989. Policy Options for Stabilizing Global Climate.
Report to Congress. Washington, DC: U.S. Environmental Protection Agency.

Leatherman, S. 1989. Coastal responses to sea level rise. -In: Potential
Effects of Global Change on the United States. J. Smith and D. Tirpak, eds.
Washington, DC: U.S. Environmental Protection Agency.

Lind, R., K. Arrow, G. Corey, P. Dasgupta, A. Sen, T. Stauffer,.J. Stiglitz, J.
Stockfish, and R. Wilson. 1982. Discounting for time and risk in energy policy.
Washington, DC: Resources for the Future.

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Meier, M., et al. 1985. Glaciers, Ice Sheets, and Sea Level. Washington,
DC: National Academy Press.

Marshak, J., and R. Radnor. 1972. Economic Theory of Teams. New Haven, CT:
Yale Press.

McCracken, M. , et al . 1989. Energy and global change. National Energy Strategy
-- Report to the Secretary of Energy.

Miller, J., and F. Lad. 1984. Flexibility, learning, and irreversibility in
environmental decisions: a Bayesian approach. Journal of Environmental
Economics and Management 11.

Nordhaus, W., and G. Yohe. 1983. Probabilistic forecasts of fossil fuel
consumption. In: Changing Climate. Washington, DC: National Academy Press.

Park, R., et al. 1989. The effect of sea level rise on U.S. coastal wetlands.
In: Potential Effects of Global Climate Change on the United States. J. Smith
and D. Tirpak, eds. Washington, DC: U.S. Environmental Protection Agency.

Revelle, R. 1983. Probable future changes in sea level resulting from increased
atmospheric carbon dioxide. In: Changing Climate. Washington, DC: National
Academy Press.

Schneider, S. and N. Rosenburg. 1989. The greenhouse effect: its causes,
possible impacts, and associated uncertainties. In: Greenhouse Warming:
Abatement and Adaptation. N. Rosenburg, et al., eds. Washington, DC: Resources
for the Future.

Titus, J. 1989. Sea level rise. In: Potential Effects of Global Climate
Change on the United States. J. Smith and D. Tirpak, eds. Washington, DC:
U.S. Environmental Protection Agency.

Weggel , J. , et al . 1989. The cost of defending developed shorelines along
sheltered shores. In: Potential Effects of Global Climate Change on the United
States. J. Smith and D. Tirpak, eds. Washington, DC: U.S. Environmental
Protection Agency.

White, R. 1989. Greenhouse policy and climate uncertainty. Bulletin American
Meteorological Society 70.

Yohe, G. 1989. The cost of not holding back the sea - economic vulnerability.
In: Potential Effects of Global Climate Change on the United States. J. Smith
and D. Tirpak, eds. Washington, DC: U.S. Environmental Protection Agency.

Yohe, G. 1987. Uncertainty and disagreement across the International Energy
Workshop poll - do the ranges match? OPEC Review 12.

Yohe, G. 1986. Evaluating the efficiency of long-term forecasts with limited
information. Resources and Energy 8.

371

RISK-COST ASPECTS OF SEA LEVEL RISE
AND CLIMATE CHANGE IN THE EVALUATION OF
COASTAL PROTECTION PROJECTS

DAVID A. MOSER, EUGENE Z. STAKHIV, and LIMBERIOS VALLIANOS
U.S. Army Corps of Engineers
Institute for Water Resources
Fort Belvoir, Virginia

ABSTRACT

Planning for federal projects designed to protect the U.S. coast can
incorporate forecasts of sea level rise and storm frequency changes due to
climate change by applying risk and uncertainty analysis techniques.
Incorporating future sea level rise and climate change into current projects
implies building projects that are too large for existing conditions. In
addition, changed future conditions that increase recurring project maintenance
costs tend to favor structural-type projects. In terms of planning current
projects, the adverse impacts of sea level rise and climate change occur too
slowly and too far into the future to have much influence on the.choice of the
type and scale of coastal protection project. This is especially true given the
higher interest rate used in present-value calculations. Therefore, the U.S.
is likely to rely on nonstructural, land use management solutions administered
by state and local agencies.

INTRODUCTION

The impending threat of climate change and sea level rise has brought calls
from various sectors for government institutions to prepare for this creeping
natural hazard. The U.S. Army Corps of Engineers is one such federal agency that
is responsible for various aspects of a diverse program responsible for water
resources and shoreline protection. The Corps recognizes that its activities
are likely to be affected by the hydrologic, meteorologic, and oceanographic
consequences of global warming and expected climate changes. One response has
been the explicit introduction of risk analysis to aid in the evaluation and
selection of alternative plans and project components to deal with natural hazard
extremes and the mitigation of their social and economic consequences. This
formal risk analysis is merely an addition to existing multiobjective evaluation

373

Economic and Financial Implications

procedures that guide federal water resources development. These procedures are
based on a body of social, economic, environmental, planning, and decision theory
literature that has been developed over the last 50 years.

Many uncertainties and unknowns are associated with the physical effects
of greenhouse warming and anticipated sea level rise. These compound the
existing difficulties of planning under conditions of uncertainty regarding
future growth, economic development, and environmental effects. The key risk
and uncertainty issues facing present-day coastal protection projects are the
following:

1. Establishing the proper baseline for evaluating the physical and
socioeconomic impacts of sea level rise,

2. the rate and magnitude of sea level rise,

3. the uncertainty of storm frequency and wave regimes under climate
change, and

4. the dominant effect of the discount rate.

Sea level rise alone, even with the present weather regime, will logically
cause the landward retreat of the shoreline following the Bruun rule (Schwartz,
1967). Weather changes associated with global warming could imply increased
variability and intensity of individual coastal storm events, further
exacerbating the present conditions of beach erosion and property damage in
coastal areas. However, the direction of the intensity and frequency of storm
events, is still largely speculative. An additional factor in the proper
selection of strategies for societal adaptation to sea level rise and storm
frequency is their rates of chanue. The immediacy of the consequences to
shorelines and coastal development will influence the choice of action.

A fundamental question that climate change and sea level rise pose for
society is how to effectively cope with the changes that appear irreversible.
Many federal, state, and local institutions are currently debating the possible
strategies and specific measures for anticipating the most severe consequences
and adapting to the inevitable changes. The Corps of Engineers, as one of these
institutions, can effectively deal only with protective measures. This paper
deals with how the Corps' economic evaluation principles and decision rules
influence the choice of a particular shore protection measure in a risk analysis
framework. There are many other effective alternative management measures,
residing within the responsibilities of the states and local communities, that
should be strongly considered in adapting to sea level rise. The range of public
measures to mitigate the potential hazards to life and property from sea level
rise and climate change will be the same as those available today under "normal"
conditions. The probable difference will be that the emphasis on alternative
management strategies will change to reflect the reality that the baseline
condition is changing. Thus, it is likely that shore protection strategies would
shift from protective measures such as groins, bulkheads, seawalls, and beach

374

Moser, et al.

nourishment to land use modification measures, which limit investments in and
subsidies to hazard-prone areas through regulation and disinvestment strategies,
such as transferable development rights and the use of financial incentives and
tax deductions.

AN OVERVIEW OF ECONOMIC EVALUATION PRINCIPLES

The federal government has a long history of planning coastal protection
projects. By providing protection against the hazard, efficiency gains can be
achieved that result in an increase in the national output of goods and services.
There are also additional regional and local economic gains that result from the
transfer of economic activity from some other location. The identification and
measurement of the national efficiency gains follows benefit-cost analysis
procedures developed, to a significant extent, to evaluate the national economic
implications of federal investments in what are inherently local water resource
projects. These procedures are codified in the "Economic and Environmental
Principles and Guidelines for Water and Related Land Resources Implementation
Studies (Principles and Guidelines)" (Water Resources Council, 1983).

Adaptive responses to sea level rise are generally the same as those
considered.for existing coastal erosion problems. These can be classified into
four approaches or options:

1. Hard engineering options -- bulkheads, groin fields, seawalls,
revetments, and the elevation of the shoreline and structures;

2. soft engineering options -- beach nourishment and dune stabilization;

3. management options -- set-back requirements, restrictions on land
development and land use; and

4. passive options -- no systematic response, allowing the coast to erode,
with private attempts to protect individual property.

Coastal protection projects, like all investments, involve spending money
today to gain predicted benefits in the future. In addition, many types of
projects, particularly the beach nourishment, maintenance type, require the
commitment to future spending to maintain the project. This future aspect
requires that the current and future dollar costs and benefits must be compared
in a common unit of measurement. This is typically in terms of their present
values or the average annual equivalent of their present values. Therefore, the
discount rate used to determine the present values influences the economic
feasibility of alternative projects. It is well known that large discount rates
reduce the influence of future benefits and costs on present values: High
interest rates generally favor the selection of projects with low first costs
but relatively high planned future maintenance expenditures over those with high
first costs but low future maintenance expenditures.

375

Economic and Financial Implications

The standard for identifying and measuring the economic benefits from
investment in a water resources project is each individual's willingness to pay
for that project. For coastal protection projects, this value can be generated
by a reduction in the cost to a current land use activity or the increase in net
income possible at a given site. A project generates these values by reducing
the risk of storm damage to coastal development. Conceptually, the risk from
storms can be viewed as incurring a cost to development -- i.e., capital
investment -- at hazardous locations. Thus, the cost per unit of capital
invested at risky locations is higher than at risk-free locations. Economic
theory predicts that the risk of storm damage in a given location results in less
intensive development and lower land value in that location as compared with
development and values if the same location had a lower risk as compared with
otherwise equivalent, risk-free locations. The risk component of the marginal
cost of capital is composed of the expected value of the per unit storm damages
plus a premium for risk. This risk premium results from the attitudes or
preferences of the individual decisionmaker toward risk. If the individual is
averse to risk, the risk premium is positive, indicating that capital must earn
a return not only to cover expected storm damages but also to compensate the
investor for taking the risk.

NATURAL SOURCES OF RISK AND UNCERTAINTY

Storms damage coastal property in several ways. In addition to direct wind-
related damage, which is ignored here, a storm typically produces a surge that
raises the water surface elevation well above the mean high tide level. This
wind-driven surge may be sufficient, even in the absence of waves, to flood low-
lying areas. In addition to the surge, storms also produce larger waves.
Property subject to direct wave attack can suffer extensive damage to the
structure and contents as well as erosion of the foundation, threatening the
stability of the entire structure. Storms also produce at least temporary
physical changes at the land-water boundary by eroding the natural beach and dune
that serve to buffer and protect the shore and property from the effects of
storms. Increased wave energy during storms erodes the beach and carries the
sand offshore. At the same time, the storm surge pushes the zone of direct wave
attack higher up the beach and can subject the dune and structures to direct wave
action.

Several components of coastal project evaluation are stochastic, so that the
evaluation can be computationally complicated. For instance, the damages from
storms are dependent on characteristics described in probabilistic terms, such
as intensity, duration, wind direction, and diurnal tide level. Since these
characteristics, in turn, influence the level of storm surge and significant wave
height, these two direct factors in storm damage are also stochastic. Sea level
rise can be considered as a shift in the base elevation for measuring storm surge
and wave height.

376

Moser, et al.

THE EVALUATION FRAMEWORK

The first step in an evaluation is to assess the baseline conditions, that
is, what will happen without the project being evaluated. In the deterministic
approach, a single forecast defines physical, developmental, cultural,
environmental, and other changes. These changes are considered to occur with
certainty in the absence of any systematic adaptive measure. This approach does
allow, however, for individual property owners to respond to storm and erosion
threats by constructing protective measures or by abandoning property. The
baseline requires assumptions to determine when these responses occur. In the
risk analysis approach, this simplistic determination of the "without" condition
is modified to incorporate uncertainties about storm frequencies, the
distribution of wave heights, and the geomorphologic changes and property losses
produced by storms and waves.

The variable sea state is measured as the sum of the level of storm surge
plus the significant wave height. The level of storm surge is a function of the
storm characteristics, so that the annual probability of storm surge exceeding
some level depends on the annual probability of storms that can generate a surge
of that level or greater. The distribution of wave heights from a storm is not
independent of the level of storm surge (Bakker and Vrijling, 1981). One can
consider the storm surge to shift the probability density function for
significant wave heights.

The final component for incorporating classical risk-analysis techniques
within the benefit evaluation framework for storm protection, as specified by
the Principle and Guidelines, is to compare the future economic development and
land values if the project is implemented with the baseline values. Without a
public coastal protection project, property owners are presumed to repair
structural losses with the damages from storms presumed to be capitalized into
the value of the land. In addition, property owners are assumed to construct
individual protective structures when the costs are less than the value of the
preserved property and the avoided expected damages to improvements. With the
project, landowners realize increases in economic rental values of land at
protected locations. This rental value increase is typically considered to be
equivalent to the annualized expected present value of avoided property losses
with the project or the avoided costs of individual protective structures. The
time stream of these benefits will reflect the stochastic nature of storm events.
An important additional consideration stems from the chronological order of
storms and damages. A large storm may result in damages that are so extensive
that the buildings are not or cannot be rebuilt. Therefore, succeeding storms
will inflict smaller losses if preceded by large storms.

The general description of the evaluation framework does not explicitly
incorporate long-term shoreline erosion. In many situations, the observed
shoreline retreat is simply the by-product of the storm history at a particular
location, perhaps in combination with relative sea level rise. In other special
cases, coastal structures such as groins and jetties may induce sand starvation
in down-drift areas. Typically, these are incorporated in project evaluation,

377

Economic and Financial Implications

based on the average rate of historical shoreline retreat. For purposes here,
any shoreline retreat is treated as storm-induced.

The increase in rental value of land is location-based, resulting from a
reduction in the external costs imposed by storms. The increase represents a
national economic development benefit, as required under the Principles and
Guidelines. It is this type of economic benefit that is compared to project
costs to determine the economic feasibility of any proposed federal project.'

Benefits produced by a project depend on the project's type and scale. Even
where two alternative projects have the same scale, as defined by the design
level of storm protection (e.g., 100-year storm or probable maximum hurricane),
the impact on benefits will differ, depending on the magnitude of residual losses
from storms that exceed the level of protection. For example, for a given level
of protection, a sea-wall is likely to result in different residual storm losses
as compared with beach and dune restoration, stabilization, and nourishment.

In addition to national economic development benefits, a second major
consideration in applying benefit-cost analysis in choosing a project and its
level of protection is the stream of future project costs. The appropriate costs
used in the analysis should provide a measure of all the opportunity costs
incurred to produce the project outputs. These national economic development
costs may differ from the expenses of constructing and maintaining the project.
For coastal protection projects, expenses would include the first costs of
project construction, any periodic maintenance costs, and future rehabilitation
costs. In addition, the project may incur environmental or other non-market
costs whose monetary value can be imputed. The nature of the stream of future
costs depends on the type of project. For instance, a structural-type project
typically has high first costs and high future rehabilitation costs but low
future periodic maintenance costs. On the other hand, a maintenance-type project
is composed of relatively low first costs but with larger recurring future
maintenance costs.

Each of the time streams of costs must be converted into present-value terms
using the prevailing federal discount rate. Note that the stream of future costs
for both types of projects, but especially the maintenance, must be defined in
probabilistic terms. The realized amount and timing of maintenance and
rehabilitation expenditures depends on the number and severity of storms
experienced at the project site in the future. Thus, the expected future cost
stream is based on the estimated probability density function for sea states.

Once the alternative formulated plans are evaluated in economic terms, the
expected net benefits can be calculated. Following the project selection

'In some cases, it may be determined that there is "no federal interest"
and no federal project. This may be the case where a "few" large identifiable
beneficiaries could organize to pay for their own protection financed out of
increased land values.

378

criteria in the Principles and Guidelines, the recommended type and scale of plan
should be the one that "reasonably maximizes" net national economic development
benefits. This is a key conceptual point in risk analysis: the net benefits
decision rule for selecting the economically optimal project simultaneously
selects the degree of protection and level of residual risk bearing. Thus, by
varying the scale each type of project, we can derive a benefit function for each
type of project. Deviations from the national economic development plan can be
recommended to incorporate risk and uncertainty considerations in addition to
the explicit risk analysis used in the econoiric evaluation. Thc-se coOd be
considerations for human health and safety or non-monetized environmental
concerns.

CLIMATE CHANGE AMD SEA LEVEL RISE

Thus far, the evaluation and selection of federal coastal protection
investments has assumed that climate and mean sea level will not change; the
underlying physical parameters and relationships yielding the historically
observed distribution of sea states have been assumed to be constant. Rost
forecasts for sea level rise suggest that it is not an immediate problem for
coastal development. In addition, there is a wide variation in the estimates
of the rate of sea level rise.

For instance, a recent National Research Council report notes that relative
sea level rise is composed of two components: (1) the localized land subsidence
or upl i ft, and (2) a worl d -wi de ri se i n mean sea I evel . (NCR, 1987). The report
adopted equations resulting in the following relationship to forecast total
relative sea level rise:

RSLR(t) = (0.0012 + M/1000).t + b-t2

where:
RSLR= relative sea level rise by year t above the 1986 level
M the local subsidence or uplift rate in mm/year, and
b the eustatic component of relative sea level rise by the year
2100 in m/year.

The value of M is fairly well established for many coastal locations: the value
of b, however, is subject to wide forecast differences. Table 2 shows the
estimates of the total relative sea level rise at Hampton, Virginia, and Grand
Isle, Louisiana, for the three scenarios adopted in the NRC report. The
variability in the predicted sea level rise offers a case for the application
of sensitivity analysis in the evaluation of project scale. In addition, the
disagreement over the eustatic component of relative sea level rise argues for
projects whose scale can be staged to account for sea level rise as it occurs.

Sea level rise can be included in the evaluation of planning alternatives
as a shift in the probability density function of storm surge in tihich the

379

Economic and Financia7 Imp7ications

variance remains constant but the mean increases by the amount of sea level rise.
This results in an increase in the site cost of capital "with" and "without" each
alternative. Note that a rise in sea level will most likely have different
impacts on the site cost of capital for different types of planning alternatives.
The incorporation of higher future sea levels in project evaluation will favor
the recommendation of larger, structural-type projects over maintenance projects.
Two additional considerations temper this conclusion, however. First, building
higher levels of protection than are economically efficient given the current
mean sea level implies that current net benefits are sacrificed. The higher
levels of protection are economically efficient only at higher mean sea levels
that may or may not occur in the future. Second, since the increase in net
benefits for a larger scale project occur in the future, the discounting process
necessary to determine the present values of benefits and costs will reduce the
influence of these future benefits on the determination of the appropriate
project scale.

One way of presenting the economic tradeoffs between design project scales
that have different time streams of future net benefits is to determine the
break-even discount rate for the projects. The break-even discount rate is the
interest rate that equates the present values of two streams of future net
benefits. The present value of net benefits as a function of the discount rate
is shown in.Figure I for two alternative projects, A and B. Project A provides
the economically effictent level of protection today ignoring sea level rise,
while B provides a higher level of protection in anticipation of climate change
and sea level rise. Notice that the present value of future net benefits for
project B exceeds the present value of future-net benefits for project A if the
discount rate is less than approximately 3.2 %. This compares to the 1989 U.S.
federal discount rate of 8 7/8*/* used for project eval uati on. In general , because
sea level rise and its effects occur relatively far in the future, incorporating
even a high forecast of future sea levels in the evaluation of project scale
will have little impact on the economically efficient project design when high
discount rates are employed. Nevertheless, the uncertain prospect of the amount
of sea level rise may support projects that are more flexible and that can easily
incorporate,staging of'project increments as sea levels change.

Similar to the above analysis, project evaluation could incorporate the
effects of forecasted Climate change, expressed as a change in the frequency of
storm events, through the calculation of: expected values and sensitivity
analysis. One hypothesis about the effect of climate change is that in many
locations the frequency of severe storms will increase over time. Since
recurring maintenance expenditures depend primarily on the frequency of storms,
climate change that increases storm frequency will shorten the time period
between these expenditures. This would tend to favor- structural -type projects,
since they have lower maintenance costs. Again, a perhaps overriding
consideration for federal projects is the impact of discounting on these future
costs and their influence on project type and scale. Thus, even though climate
change may result in a dramatic increase in total lifetime project costs, most
of the increase occurs beyond the first 15 to 20 years of project life, which

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Table 1. Total Relative Sea Level Risk Forecasts in Meters

Year Hampton, VA Grand Isle, LA

t 1 11 111 1 11 111

1985 0.0 0.0 0.0 0'0 0.0 0.0
1990 0.0 0.0 0.0 0.1 0.1 0.1
1995 0.0 0.0 0.1 0.1 0.1 0.1
2000 0.1 0.1 0.1 0.2 0.2 0.2
2005 0.1 0.1 0.1 0.2 0.2 0.2
2010 0.1 0.1 0.2 0.3 0.3 0.3
2015 0.2 0.2 0.2 0.3 0.4 0.4
2020 0.2 0.2 0.3 0.4 0.4 0.5
2025 0.2 0.3 o.3 0.4 0.5 0.6
2030 0.3 0.3 0.4 0.5 0.6 0.7
2035 0.3 0.4 0.5 0.6 0.7 0.8
2040 0.3 0.4 0.6 0.6 0.8 0.9
2045 0.4 0.5 0.6 0.7 0.8 1.0
2050 0.4 0.6 0.7 0.8 0.9 1.1
2055 0.4 0.6 0.8 0.8 1.0 1.2
2060 0.5 0.7 0.9 0.9 1.1 1.3
2065 0.5 0.8 1.0 1.0 1.2 1.5
2070 0.6 0.8 1.1 1.1 1.3 1.6
2075 0.6 0.9 1.2 1.1 1.4 1.8
2080 0.7 1.0 1.4 1.2 1.6 1.9
2085 0.7 1.1 1.5 1.3 1.7 2.1
2090 0.8 1.2 1.6 1.4 1.8 2.2
2095 0.8 1.3 1.7 1.4 1.9 2.4
2100 0.9 1.4 1.9 1.5 2.0 2.6

Implied Sea
Scenario Coefficient Level Rise by 2100

1 0.000028 0.5
11 0.000066 1.0
111 0.000105 1.5
RSLR (0.0012 + M/1000)-t + b-t2
M Rate of subsidence or uplift in mm/yr
3.1 for Hampton, VA
8.9 for Grand Isle, LA
b The rate of change in rate of growth in eustatic tea level rise for
scenarios 1, 11, and 111.
Source: Based on NRC (1987).

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Economic and Financial Implications

$240 -

$220-

$200- Design B -- anticipating sea level rise

$180-
Scenario III

$160-

Z $140-
0
a) $120-
-2
M $100-
> Design A ignoring sea level rise
$80-
Scenario III
9) $60-
CL

$40-

$20-
CL
X
W $0-

($20)-

($40)-
1,00/0 3.0% 5.0% 7.@% 9.0*/0

Discount Rate in Per Cent

Figure 1. Expected present value of net benefits as a function of discount rate.

has little influence on the present value of net benefits. (See the economic
section of the conference report for a further discussion on discounting.)

CONCLUSIONS

Coastal protection projects can incorporate forecasts of sea level rise and
storm frequency changes due to climate change through the application of risk
and uncertainty analysis techniques. The incorporation of these forecasts is
not a trivial matter, but well within the probabilistic analyses currently
employed to estimate project benefits and costs for coastal projects. When the
effects of sea level rise and climate change occur in the future, in-place
structural projects of larger scale than those warranted under the current sea
level and storm frequencies would offer greater benefits than those designed for
the current conditions. In addition, sea level rise and climate change, which
increase recurring project maintenance costs, tend to favor structural-type
projects.

Risk-cost analysis is not likely to yield definitive answers to the problem
of choosing adaptive measures to cope with the risk of sea level rise. Other
considerations that incorporate cultural, social, or environmental aspects

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related to sea level rise may be more important in choosing adaptive measures.
Risk-based approaches remind the analyst, however, that hard engineering options
may exacerbate losses by encouraging development and fostering a false sense of
security. Hard engineering adaptations to sea level rise, particularly the
barrier type, have the potential for disaster should natural events exceed their
designed level of protection. Therefore, decision-makers should be wary of
engineering solutions with high residual risks.

At present, there is considerable disagreement over the degree of sea level
rise and the impact of climate change on storm frequency. More important, the
adverse impacts on storm damages occur too far into the future, given the nature
of discounting and the level of the federal discount rate, to have much influence
on the economically efficient type and scale of project recommended today. There
is likely to be a greater reliance on nonstructural, land use management
solutions that require state and local regulatory controls. The uncertainties
about the magnitude and rate of change in sea level rise emphasize the need to
maintain flexibility and emphasizes the adoption of an incremental approach that
preserves options.

BIBLIOGRAPHY

Bakker, W.T. and J.K. Vrijling. 1981. Probabilistic design of sea defences.
In: Proceedings of the Seventeenth Coastal Engineering Conference, Vol II. New
York: ASCE.

Bruun, P. 1962. Sea level rise as a cause of shore erosion. Journal of
Waterways and Harbors Division 1:116-30.

National Research Council. 1987. Responding to Changes in Sea Level:
Engineering Implications. Washington, DC: National Academy Press.

Schwartz, M.L. 1967. The Bruun theory of sea level rise as a cause of shore
erosion. Journal of Geology 75:76-92.

U.S. Water Resources Council. 1983. Economic and Environmental Principles and
Guidelines for Water and Related Land Resources Implementation Studies.
Washington, DC: U.S. Government Printing Office.

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SPEECHES

GLOBAL PARTNERSHIPS FOR ADAPTING TO GLOBAL CHANGE

HONORABLE JOHN A. KNAUSS
Undersecretary of Commerce for
Oceans and Atmosphere
U.S. Department of Commerce
Washington, DC

I am pleased to join you this morning here in Miami. Whoever chose this
site for a workshop on Adaptive Options and Policy Implications of Sea Level Rise
certainly chose well. Here we see a prime example of a fragile coastal
environment; a heavily built up coastal area; an excellent example of the
possible costs and dislocations associated with a significant rise in sea level.

You are here to take on a significant challenge -- how to respond to
potential major changes in our global environment. The purpose of this workshop
is to gather information and exchange views on adaptive options -- to learn how
to protect resources and minimize economic disruption resulting from a potential
rise in sea level.

For those of you, like myself, who have long been concerned with
environmental issues, these last few months have been almost breathtaking.
Environmental issues, in particular, the possibility of human-induced global
change, have reached center stage in much of the world. The global environment
has become a priority issue in summit discussions. For example, fully one third
of the summary communique that came out of the economic summit, the G-7
conference in Paris this past summer, was devoted to environmental issues. Prime
Minister Thatcher's recent speech to the United Nations General Assembly was
devoted entirely to environmental matters. Here in the U.S., President Bush
has placed environmental concerns near the top of his agenda.

In the past year, the Intergovernmental Panel on Climate Change (IPCC),
created by the World Meteorological Organization (WMO) and the U.N. Environment
Programme in 1988 to address the serious potential consequences of climate
change, has become a dominant international force. Three working groups under
the IPCC focus on various aspects of climate change.

Working Group I is examining the state of the science: What do we know
and what don't we know?; How can we gather more information?; How can we be sure
about the various aspects of climate change, particularly the role of man in
generating those changes? Working Group 2 is investigating the socioeconomic
and environmental impacts of climate change. For example, if there is climate

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change, there will be more rainfall in one region than in another; what impacts
will that have? There also will be warming of the oceans; what impact will this
have on fisheries? Working Group 3 is focusing on response strategies to climate
change. It is under the auspices of this third working group that the U.S. is
hosting this conference.

The Netherlands was a member of the U.S. delegation to the Ministerial
Conference on Atmospheric Pollution and Climate Change. At that conference,
there was agreement to use the results of the IPCC deliberations, including the
results of workshops such as this, as the basis for a framework convention on
global change. Such a convention probably will be negotiated in the next two to
three years. The negotiations and the decisions concerning any frame-work
convention on global change and its subsequent protocols will be strongly
influenced by the work of the IPCC; and by extension, will be strongly influenced
by your deliberations this week.

We're here to discuss sea level rise. What about sea level rise? What do
we know about it? Geologists have long known that most shoreline areas change
constantly, because of silting, shoaling, and flooding, and because of changes
in sea level, caused either by a change in the ocean volume, or by a subsidence
or rise in the coastal land area.

Over geological time scales the shoreline is a very dynamic feature. Even
on a scale of decades, we have often seen significant changes in the shoreline
__ much of those changes caused by either the sinking or rising of the land.
In much of Scandinavia, for example, sea level is dropping -- not because there
is less water in the ocean but because the earth is rising, at a rate of about
I cm a year. This rise in the Earth's surface, also occurring in Canada and much
of the polar regions of the Northern Hemisphere, is due to the isostatic
adjustment that occurred after the disappearance of the glaciers some 10,000
years ago. In Japan, one of the more tectonically active regions of the earth,
depending on which part of the country you're in, sea level is either sinking
or rising, at rates of from 0.5 to 2 cm per year. Again, this is due to land
changes, not changes in sea level.

So, how should we respond to shoreline changes? One might argue that a
prudent nation would build back from the shore, and leave the dynamic, constantly
changing shoreline alone. If we all did this, there would be no need for
workshops such as this one. However, we must have our coastal ports. Many of
the great cities of the world began as ocean ports -- New York, Venice, Rio de
Janero, Rotterdam. -Are they to be abandoned because of rising sea level? Yet,
some island nations, such as the Maldives and the Trust Territories in the
Pacific, could lose much of their total land as a result of a significant rise
in sea level. Nations such as Bangladesh could suffer significant loss of land
area because they are built on a coastal plain, as could some of the U.S. Gulf
Coast states (e.g., Louisiana and Texas), which are geologically similar.

Coping with rising sea level, or sinking land level, is not a new
phenomenon. Venice, which has been grappling with this problem for years, has
been sinking into the ocean at about 20 m a century. The Netherlands decided

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long ago that if they were to provide enough land for their citizens, much of
it would have to be below sea level. More than 50 percent of the Netherlands
is now below sea level. Here in the United States, the great port city of New
Orleans is some number of feet below the Mississippi River, which flows
alongside.

Thus, while the risks of living on the shore may be high, the benefits, and
often the necessity, of coastal living usually predominate.

Given the fact that this is not a new problem, why the increased interest
in sea level rise? There are at least two reasons. One is that what we are
facing is a global issue, not a regional one, not a local one. A rise in sea
level due to melting of glaciers and expansion of sea water will have a worldwide
impact. Second, and more important, particularly in a political sense, this
change in sea level will be human-induced. If our activities cause an increase
in global temperature, then we are responsible for a rise in sea level, because
one consequence of global warming is an increase in the volume of the ocean and
a consequent worldwide rise in sea level.

The issues of climate change and sea level rise, therefore, are much more
than fodder for scientific discussion. They are truly global issues that affect
us all. The diversity of the attendance here -- scientists, policy-makers,
diplomats, academicians from 38 countries -- reflects both the global nature and
the importance of these matters.

How much do we know about climate change and sea level rise? To a large
degree, our decisions in the future will be based on our knowledge about the
risks involved. To support the decisions we have to make, we must improve our
ability to understand and to forecast trends in climate change and sea level
rise. Part of our strategy to address global change must include improving the
data and information we have available.

As the Administrator of the National Oceanic and Atmospheric Administration
(NOAA), this is a particularly important issue to me personally, and to my
agency. And as a scientist, I must acknowledge that the present data and
information base is not as robust as many of us would like. On the other hand,
what we do know is sufficiently compelling to generate wide concern. There is
a growing sense that we cannot wait until we are absolutely certain before we
begin to take at least limited action, and under any circumstances, prepare for
what might follow.

What we do know is that atmospheric concentrations of carbon dioxide have
increased nearly 30% within the last 100 years and are now higher than at any
time in the last 40,000 years. While we have not been measuring carbon dioxide
for 40,000 years, we can get some estimate of what C02 concentrations were back
then by measuring the air trapped in ice cores where the ice was deposited 20,000
to 100,000 years ago. It is quite clear there is more CO, in the atmosphere now.
And the concentration of C02 has been increasing at a rate of about 4% per
decade. There is no doubt that human activities are generating enormous amounts
of carbon dioxide and other radiatively important gases, such as methane and

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chlorofluorocarbons (CFCs). We are affecting Earth's heat budget as a
consequence. How the global climate will respond to these changes in the heat
budget is still a matter of debate.

A second debatable issue is whether or not we have already seen global
warming as a result of increased carbon dioxide. There are various opinions.
At least some studies for which long-term temperature records were examined
indicate that present global temperatures are the highest ever recorded and still
rising. For example, one analysis of temperature from land-based sites has
documented an observed worldwide increase in temperature of 0.40C since the start
of the industrial revolution. On the other hand, two recent articles published
by NOAA scientists have shown that there has been no significant increase in
temperatures over the contiguous U.S. in the last 100 years.

These two seemingly disparate results are not necessarily in conflict. We
can indeed have a worldwide warming that will not be uniform. We can be almost
certain it will not be uniform; some areas might even cool. But the average
temperature of the Earth will rise.

Projecting the change in sea level from global warming is equally complex
and uncertain. There is general agreement in the scientific community that a
rapid sea level rise, projected by some a few years ago, is rather unlikely.
It is generally accepted that global sea level has increased at a rate of 1-2
m per year over the 1 ast century. But even here, the uncertainty is great.
Detecting that small of a change is not, easy. In many parts of the world, the
tectonic movement of the land is 5 to 10 times greater. Furthermore, the present
worldwide network of tide gauges for measuring sea level was established
primarily for purposes of maritime safety, and not for the purpose of determining
the ri se and f al 1 of sea 1 evel .The distribution is not ideal for attacking this
problem. Many of my colleagues would not be too surprised to find that when all
the data is in and analyzed, it will not be possible to say whether or not there
has been a rise in sea level in the last 100 years.

As for the future,. in spite of all the well-publicized concern about global
warming, we must understand that there is still considerable uncertainty among
scientific experts about a number of the most critical factors that determine
global warming and, as a consequence, global sea level. We remain uncertain
about the magnitude and the timing of such changes, as well as about the specific
impacts in different regions of the world.

The Earth system is composed of a variety of interactive parts, These
climate interactions include cloud cover, snow and ice, hydrology, and ocean
circulation, amongst others. Key scientific questions focus on the processes
that tie the system together.

One of the biggest areas of uncertainty is the role of the oceans in climate
change. Although the sun drives the system, the ocean serves as a somewhat
erratic "fly wheel" that mitigates the sharp seasonal changes and interannual
variations. We must improve our understanding of ocean variability and how the

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ocean interacts with the atmosphere on a global basis. That point has been
stressed recently.

The World Meteorological Organization noted in June 1989 that existing
ocean observing networks generally are not adequate to meet the international
scientific requirements for climate monitoring, research, and prediction. A
month later, in July, the IOC determined that there is an urgent need to
substantially modernize and expand the existing global ocean observing systems.
I agree. But monitoring the oceans is difficult because of the vast expanse,
the diversity of ocean processes, and quite frankly, because there is still much
that is poorly understood.

There currently exists a surface-based observational network that is a
mixture of hundreds of various ocean measurement systems and platforms; in
addition, there are nearly 8,000 worldwide volunteer observing ships. Some of
these programs are operational, while others support research programs. They
are managed by an equally varied group of more than 100 nations, plus
intergovernmental bodies and agencies, many with different missions and
objectives. The systems are often incompatible in type, location, data format,
and communication links. That existing network, such as it is, is an unfinished
patchwork quilt; many pieces are in place, some are not. Before we truly
understand the ocean's role in global warming, we will need to pull all the
existing pieces together and begin "sewing" the quilt. We are on our way to
doing just this.

Major international programs such as the Tropical Ocean Global Atmosphere
(TOGA), and the World Ocean Circulation Experiment (WOCE), have begun to provide
the needed scientific bases for defining the network. And they have begun to
assemble some preliminary pieces. But there is still much to be done.
Satellites, for example, can only do part of the job. They are wonderful for
looking at the atmosphere; satellites cannot be used to penetrate the ocean --
they can only look at the surface of the ocean. For example, satellite
measurements cannot tell us anything significant about the movement of heat from
one ocean basin to another.

Once the observational network is complete, we must identify the
intergovernmental mechanisms needed to maintain it.

As the U.S. Earth systems agency, we at NOAA have the responsibility for
monitoring and predicting environmental change. We have a major role in the
scientific examination of global warming and attendant sea level rise. NOAA
has already begun a comprehensive effort to improve the global ocean-observing
system. One part of that task is to improve our tide gauge network so we can
better monitor changes in sea level.

NOAA has been in the business of measuring tides and water levels for more
than 140 years. Our longest continuous series of measurements began at San
Francisco in 1854. And, of course, compared to some of our European colleagues,
we are rather "Johnny-come-latelys" in the business of measuring sea level.

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Sea level measurement is going through a revolutionary change at present.
Because of recent advances in geodetic positioning, it is now possible to measure
the true sea level with a precision never before possible. That is, we can
distinguish the movement of the tide gauge caused by the land from movement
caused by actual change in sea level.

In summary, understanding and predicting global change requires a truly
global partnership. International organizations are defining the requirements

for a global ocean observing system and will play a pivotal role in maintaining
that observing system over the long term.

It is a challenge for each of us personally to work within our country for
increased scientific research and intergovernmental support for a global
observation network.

Your task this week is to consider the consequences of sea level rise
resulting from global change, to identify rational approaches to climate change
and sea level rise, and to consider the policy implications of such responses.
If we think that solving the scientific riddle is a challenge, I expect that the
search for responses and solutions will be even more of a challenge. It is a
process that we need to begin now.

It may be the task of science to provide us with high-quality information
and predictions that can guide our efforts, but we cannot wait for science to
give us definitive answers before we get on with the planning and the assessing
of our options.

392

LUNCHEON REMARKS

JOHN DOYLE
Office of the Assistant Secretary
for Civil Works
U.S. Army
Washington, DC

It is a distinct pleasure for me to represent the Assistant Secretary of the
Army for Civil Works and, with my co-hosts from NOAA and U.S. EPA, to welcome
this distinguished body of international delegates and to participate with you
in the exchange of information and ideas at this IPCC Sea Level Rise Workshop.

Let me begin by explaining that my office oversees the civil-oriented work
of the U.S. Army Corps of Engineers which is the principal U.S. agency for
development of water resources projects throughout the United States. The Army
has been doing such work since 1824, when it had the country's only organized
group of engineers and was charged by the Congress to develop navigation
projects.

Since 1824, the Army's responsibilities have been expanded by the Congress
to encompass virtually all types of water resources development projects
including single purpose navigation, flood control, and coastal projects.
Multipurpose projects also include features that provide for industrial and
municipal water supply, hydroelectric power production, irrigation, resource
conservation, and recreation. We also have regulatory responsibilities, which
include management of the nations' waters, including controls associated with
tidal and non-tidal wetlands.

I must emphasize that in the process of executing our water resources
development and regulatory responsibilities, the Department of the Army, through
the Corps of Engineers, works with a wide spectrum of other federal agencies,
as well as state and local governments, and public interest groups. Through this
cooperative and collaborative process we in effect, join in multiple partnerships
with others to evaluate and decide on the broad social, economic and
environmental implications of alternative public investment options related to
water resources development and conservation. Hence, we and our companion
agencies of the U.S. Government find the IPCC a familiar and comfortable forum
in which to participate and to join with you as partners in formulating solutions
to problems that could arise in the event of human-induced climate change.

With that brief background, I would now like to share with you the views
of the U.S. Department of the Army concerning the implications of a possible
future accelerated ri se i n sea level , and what we are doing at present to address

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the consequences of that potential phenomenon in terms of planning adaptive
options.

First, we do not view the potential for accelerated sea level rise with
either alarm or complacency. In general , there does not appear to be a
substantive basis for broad and immediate emergency action. Moreover, in many
situations in the United States and throughout the world, the effects of an
increase in the level of the seas could be accommodated in the normal course of
maintaining or replacing existing facilities or protective structures without
extraordinary added costs related to sea level rise. However, near-term action
may be warranted in limited geographic areas having low topographic elevations
and/or significant land subsidence rates.

The options available for adapting to sea level rise with respect to
developed areas are those traditionally used for responding to threats of storm
tides and wave action in coastal and estuarial zones, namely: (1) stabilization
measures, such as seawalls, bulkheads, revetments, beach fills, groins,
breakwaters, flood walls, levees, and estuarial or sea-entrance tidal barriers;
(2) elevating of lands and facilities usually with the application of
stabilization measures; and (3) retreat from hazardous or threatened areas.
Advanced measures such as land use management can be employed in areas which are
presently extremely hazardous or would become so in the event of a marked rise
in sea level.

In regard to the choice of an option or set of options, most developed
areas that would be exposed to the impacts of a rising sea level possess their
own singular mixes of physical, social, economic, political and environmental
characteristics. These composite characteristics would, case by case, govern
the choice, initiation, and phasing-in of an adaptive response or set of
responses to a rise of sea level. Doubtless, the implementation of responses,
from national or global perspectives, would be a slowly evolving process
following the anticipated gradual rise in sea level, should enhanced greenhouse
effects occur.

In any case, those charged with planning, design, or management
responsibilities in the coastal and estuarial zones should be aware of and
sensitized to the possibilities and quantitative uncertainties pertaining to
future sea level rise. It may be some time before we know what changes, if any,
are taking place in the levels of the seas vis-a-vis climate change. Moreover,
if this phenomenon does occur and is detected, additional time will transpire
before definite rates and trends of the rise are established relative to land
surfaces in specific areas of concern.

In the-meantime, we should, wherever possible, conduct our activities so
as to leave options open for the most appropriate future response without undue
current investments, social and economic disruption, or environmental damage.
I realize that this is not an easy task, even when the involved institutional
establishment has a common viewpoint on the potential problem. Certain realities
and constraints must be recognized. For example, traditional benefit-cost
analyses, with the high discount rates currently in use, do not generate
significant benefit values for the prevention of damage events that are expected

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Doy7e

to occur 35 to 50 years i n the f uture even when the I i kel i hood of such events
can be strongly supported by past events and statistical analyses. Thus, water
resources projects for which benefits are long term are normally deferred in
favor of more certain, near-term benefits.

Nevertheless, something can be done to prepare for potential future
problems. As an illustration, many protective structures such as levees,
seawalls, and breakwaters can be planned and designed with features that allow
for future incremental additions that, if needed, could accommodate increased
water levels and wave action. This can be done, in many cases, without
significant additional costs in the initial investments.

Other actions can be taken now, or strategies and technologies developed,
that require little investment and can in fact, reduce current operating
expenditures. One important example that comes to mind is the beneficial use
of material dredged from navigation projects in the creation of tidal wetland
habitats. We are vigorously pursuing this option at both the research and the
field application levels. This use of dredged material can, in proper
circumstances, reduce the costs of disposal of the material while offsetting
wetland losses due to sea level rise or other causes.

Though sea level rise would seemingly reduce navigation dredging
requirements by naturally providing deeper waters, such an effect would, if at
all, be short lived. In this connection, one has only to consider that vertical
shoaling rates of one meter per year are extremely common, and that little
advantage to navigation would be gained by a I- to 2-meter rise in sea level over
a 100-year period. In any case, we expect that overall navigation dredging
demands will not be significantly affected by changing sea level, albeit, long-
term changes in areal distributions of shoaling may attend a gradual rise in sea
level.

In this country, the possibility of a large-scale program to create tidal
wetlands with dredged material is evident in considering that over the past
decade, the Army Corps of Engineers has excavated an average annual quantity of
250 million cubic meters of uncontaminated dredged material from navigation
projects. Moreover, most of this material is removed from channels and harbors
in the coastal and Great Lakes regions. If placed to a thickness of I cm, 250
million cubic meters of dredged material each year would cover an area of about
25,000 hectares. Admittedly, all uncontaminated dredged material could not be
effectively used for purposes of wetland creation, but a substantial amount could
be applied in that way and would significantly offset loss of tidal wetland due
to sea level rise.

Now a few words about what we are doing to address the basis issue.

To assure a consistent approach to considerations of possible accelerated
sea level rise, the Army Corps of Engineers has adopted uniform planning
procedures. The procedures require that potential sea level change be considered
in every project feasibility study undertaken within the coastal and estuarial
zones. Study areas are to extend as far inland as the potential future limits
of tidal influence. This applies primarily to the study and formulation of
shore protection, flood control, and navigation projects.

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The future head' of tides is based on the sea level rise scenario considered
most probable by the National Research Council in its 1987 report on the subject
of responding to changes in sea level. S' pecifically, the rate of rise of sea
level' is represented by an exponential curve resulting in a 1-meter rise by the
year'2100. Also to be considered is the National Research Council's most likely
high envelope of sea level rise, which again, is represented by an exponential
curve, but one that reaches a rise level of 1.5 meters by the year 2100. Where
land areas are experiencing subsidence or uplift, those respective rates of
change must be added to or subtracted from the previously mentioned curve values
in order to obtain a tota-1 relative sea level change.

On the basis of these possibilities, our procedures call for the performance
of sensitivity tests or analyses to determine what effects (if any) the changes
in the rate of sea level rise would have on the evaluation and selection of a
plan. Emphasis is placed on developing strategies that would be appropriate for
the largest possible range@'of uncertainty with regard to future sea levels. It
is important to mention, however, that the planning process in which sea level
rise is being evaluated embraces many project-related social, economic, and
environmental considerations that may or may not be influenced by the question
of future sea level. Accordingly, sea level is only one of many factors to be
considered in the weighing and balancing necessary to arrive at optimal project
formulation.

The Response Strategies Work Group of IPCC met in Geneva in early October
and developed five papers that are to be used by the subgroups as guidance in
developing subgroup reports. All those papers are important to the work going
on here. However, the paper dealing with technology development and transfer
is particularly relevant. In summarizing my remarks today, I would like to
emphasize several themes in that paper.

First, we are discussing adaptive techniques. Some discussions in Geneva
indicated that if climate and sea level changes occur in significant measure,
the changes will be sufficiently far in the future and sufficiently gradual that
we do not have to be concerned about them now. The Geneva meeting wisely
rejected that notion. While we agree with the assessment that significant change
is not imminent, we do not agree that we can wait until some uncertain future
time to address the need for new technologies and new institutional and
management mechanisms to advance those technologies. It can certainly be argued-,
that we may never need new technologies or new management mechanisms. But the
counter argument is that we do not anticipate potential problems, we may not
have time to react intelligently if they should arise.

In connection with addressing the technology, we must also improve and
refine our ways of assessing the economic, environmental, and social impacts of
these potential changes. The interrelationships are complex. We will need to
put the best mi nds to work on these probl ems. That i s why you peopl e are here.
The task ahead is monumental. I urge you to continue your work in earnest. Good
luck, and best wishes.

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