The Rising Sea

The RISING SEA

Orrin H. Pilkey and Rob Young

Island Press - Shearwater Books

Washington | Covelo | London

A Shearwater Book

Published by Island Press

Copyright © 2009 Orrin H. Pilkey and Rob Young

All rights reserved under International and Pan-American Copyright Conventions. No part of this book may be reproduced in any form or by any means without permission in writing from the publisher: Island Press, 1718 Connecticut Ave., NW, Suite 300, Washington, DC 20009.

SHEARWATER BOOKS is a trademark of The Center for Resource Economics.

Library of Congress Cataloging-in-Publication Data

Pilkey, Orrin H., 1934–

The rising sea / Orrin H. Pilkey and Rob Young.

p. cm.

A Shearwater Book.

Includes bibliographical references and index.

ISBN-13: 978-1-59726-191-3 (cloth : alk. paper)

ISBN-10: 1-59726-191-2 (cloth : alk. paper)

ISBN-13: 978-1-59726-643-7 (Electronic)

1. Sea level. 2. Coast changes. I. Young, Rob. II. Title.

GC89.P48 2009         363.34′93—dc22

2009006152

Printed on recycled, acid-free paper img_03

Design by David Bullen

Manufactured in the United States of America

Keywords: Sea level rise, West Antarctic ice sheet, Greenland ice sheet, shoreline erosion, flooding, barrier islands, global warming, climate change, climate skeptics, coastal hazards, coastal management

To Walter Pilkey

for a lifetime of friendship and inspiration

To David Robert Young

who taught me more than he would ever know

Contents

Preface

Chapter 1: Living on the Edge

Chapter 2: Why the Sea Is Rising

Chapter 3: Predicting the Unpredictable

Chapter 4: The 800-Pound Gorillas

Chapter 5: A Sea of Denial

Chapter 6: The Living Coasts

Chapter 7: People and the Rising Sea

Chapter 8: Ground Zero: The Mississippi Delta

Chapter 9: Sounding Retreat

References

Acknowledgments

Index

Preface

During the past 2.5 million years, massive continental ice sheets advanced and retreated many times across planet Earth's northern hemisphere. With each advance, the amount of water bound in ice increased, and the level of the sea dropped. With each retreat of the ice sheets, meltwater was released, and the level of the sea rose. Over this time, ocean level has fluctuated across a range of more than 500 feet (150 m), and shorelines have moved landward or seaward tens of miles as a result. In fact, sea level change has been a constant part of earth history as long as there has been an ocean.

So, why all the fuss about the seemingly small sea level rise today? Simply put, the difference is us. Modern sea level rise is encountering for the first time a densely developed shoreline, putting the ways of life of millions of people at risk.

As the current rate of sea level rise accelerates, it imperils our cities, ports, and resorts that are jammed up against the shore. Most of this massive infrastructure is virtually unmovable, or very difficult to move. Future flooding of some cities such as Miami and Singapore is a certainty with rises as little as 2 feet (0.6 m), as is the mass migration of large numbers of refugees from low-lying delta regions to higher ground. In some cases, plans are afoot to move entire cultures back from the sea, such as the Alaskan Inupiat Eskimos and the atoll dwellers of the Maldives in the Indian Ocean and Tuvalu in the Pacific Ocean. Several experts now believe that some communities in the Mississippi Delta should be moved in their entirety to new and higher sites.

In one sense, the human species has been through this before. There is ample evidence of Native American settlement on what are now submerged continental shelves. The ruins of ancient Alexandria on the Nile Delta and other once important cities lie submerged on the floor of the Mediterranean Sea. Alexandria fell into the sea, not as a result of a gradual sea level rise but because of a catastrophic and instantaneous sinking of the land surface during an earthquake. Ancient migration routes like the one across the Bering Strait between Siberia and Alaska were submerged and effectively closed by the rising sea many thousands of years ago.

The current sea level rise of about 1/8 inch (0.3 cm) per year is not perceptible to the casual observer. And because it's not visible, it doesn't impress. But anyone who frequents the coast can see much evidence of recent sea level change. For example, entire island communities have disappeared from parts of the Chesapeake Bay. On Portsmouth Island on North Carolina's Outer Banks, a cemetery used by early English settlers has become a salt marsh, while the old pipes that are supposed to drain surface water runoff from South Carolina's Charleston Peninsula are now partially blocked at high tides. And in the Marshall Islands, salinization of the soil caused by rising sea levels has halted centuries-old gardening practices. Vegetables once grown in small family plots now are planted in abandoned fifty-gallon oil drums filled with soil. And geologists who study the polar ice sheets of Greenland and Antarctica have been recording changes that have momentous implications.

All indications are that we should be alarmed about the future of sea level rise and should be doing something about it now. We chose to write this book because we believe the public needs to have a clear guide to the critical but basic facts about sea level rise and its implications, in order to make intelligent decisions. The existence of a huge manufactured-doubt industry is part of the reason for the relative lack of societal concern about sea level rise. In fact, we were both unaware of the extent of this industry until we started researching this volume. One book written for children even argues that melting of the Antarctic and Greenland ice sheets won't affect sea level rise much. The author is actually off by 200 feet (61 m), which is the amount the sea level will rise if the ice sheets melt!

Between us we have sixty-five years of experience studying marine and coastal processes, and we both have long been involved in the societal debates over eroding shorelines. Rob Young spent his childhood on the Virginia shores of Chesapeake Bay, where he was fascinated by stories of disappearing islands. As a doctoral student at Duke University under Pilkey's supervision, Young studied the response of wetlands to sea level rise along the shores of Pamlico and Albemarle sounds in North Carolina. Wetlands such as salt marshes move inland in response to rising sea level in spurts, he discovered, corresponding either to forest fires or to storms from the sea. Forest fires removed the vegetation that resisted shoreline retreat, and storms overcame that resistance.

Orrin Pilkey grew up in the desert of Washington State, far from the sea. Even though he lived near the West Coast, his first childhood view of a beach was in Atlantic City, New Jersey, where feeding the pigeons left the strongest impression. Pilkey has looked at sea level rise evidence and the mode of island response on many of the world's barrier islands. He has observed Colombian Pacific fishing villages where sea level rise rates are so high (due to sinking land) that homes have been designed to be moved to a new location by a small work crew without the help of any machinery. Both authors have investigated heavily developed coasts from Dubai to Daytona, where sea level rise will have a huge impact on the beaches lined with immovable seawalls and high-rise buildings.

In the text that follows, we hope to make the case that the world is poised on the edge of a cliff (of its own making). We must act now by responding to the challenges of sea level rise in a planned and rational way, taking a long-term view. If we don't start planning now, a huge natural disaster is facing us. It comes down to accepting the challenge of the rising sea or ignoring it until it is too late and we drive over the cliff.

Chapter 1

Living on the Edge

All the rivers run into the sea; yet the sea is not full.…

Ecclesiastes 1:7

A RISING SEA is not something that may happen in the future. It is already upon us. Planners turned down construction of a large residential development on the Yorke Peninsula, South Australia, because it would be flooded by rising seas. In England, regulators declared that six small villages on the Norfolk Broads northeast of London will need to be abandoned as sea level rises. To avoid the rising sea, the 580 Inupiat Eskimo inhabitants of Shishmaref, Alaska, will likely be moved to the mainland at a cost of several hundred thousand dollars per resident. On barrier islands along the Pacific coast of Colombia where the sea level is rising with particular rapidity (because the land is also sinking), moving buildings and entire villages to higher ground is already a routine matter. In rural Cape Town, South Africa, a blue line may be established seaward of which nothing can be built because it would lie within an expected flood zone from sea level rise. Plans to abandon many Pacific atolls are now on the drawing board because they will soon be flooded by the expanding oceans. And in South Carolina, retreat from the shoreline in response to the sea level rise is now official state policy.

Still, despite strong evidence of global warming and attendant sea level rise, many communities, governments, and developers continue to ignore the inevitability of a continued rise in sea level and the corresponding increase in shoreline erosion. Singapore continues to fill in its bays to create more low-elevation land for development. In a stunning act of developmental hubris, the government of Dubai has constructed spectacular, palm-shaped artificial islands along the Persian Gulf providing space for hundreds of homes, all at low elevation and immediately susceptible to even modest sea level rise. In the United States, the State of Florida seems content to spend billions of dollars in a losing battle to hold the shoreline in place with artificial beaches, breakwaters, and seawalls while high-rise beachfront construction continues apace. And state and federal officials continue to insist that most Mississippi Delta communities can be maintained in their present location despite recent rapid sea level rise augmented by subsidence (sinking) of the land.

Global warming is changing many things: the extent of ice on the surface of the Arctic Ocean, the extent of mountain glaciers, patterns of rainfall and drought around the world, and routes of ocean currents. As the oceans warm, wide swaths of coral reefs, responsible for much of the diversity of marine life, may be degraded as human activities prevent their natural expansion to the north or to the south away from the equator. Shoreline-hugging and biologically important salt marshes and their warm-water equivalent, mangroves, already seriously reduced by the activities of humans, will further degrade as sea level rises. The distribution and the migration pathways of land mammals, birds, and insects will change, and some species will disappear entirely. Mosquitoes will appear in the high Arctic.

Of all the ongoing and expected changes from global warming, however, the increase in the volume of the oceans and accompanying rise in the level of the sea will be the most immediate, the most certain, the most widespread, and the most economically visible in its effects.

Substantial sea level change will play a critical role in humankind's future just as it sometimes has in the past, when it even became the subject of myth. Plato, for example, suggested that nine thousand years before his time an ancient civilization had existed on an island called Atlantis, only to disappear somehow beneath the waves. Some writers today cling to a belief that the Bahama Banks hold the answer to the island's disappearance, that the long, narrow bands of underwater limestone there (actually cemented beach sand) are remnants of either the mythical city's roadways or its building foundations. Others of the Atlantis faithful believe that a cataclysmic event such as a volcanic eruption destroyed the island, perhaps the same eruption that destroyed the Aegean island of Thera about 1500 BC. Still others believe Plato made up the whole thing.

In any case, it has been established that during a period forty thousand to sixty thousand years ago in which sea level was considerably lower than it is today, Aborigines walked across an exposed land bridge between New Guinea and Australia, and some of these early Australians walked on from Australia to Tasmania. The first Americans may also have taken advantage of a more recent comparatively low sea level, perhaps eleven thousand years ago, to cross the Bering Land Bridge from Asia to North America. Stone Age people at the same time must have crossed back and forth between the British Isles and Europe. Eventually, as we know, the sea rose and covered these ancient access routes, changing the face of the earth and the lives of its people.

Many societies are candidates to be the first in our time to suffer catastrophic impacts from impending sea level changes. Eventually, every nation with a coast will feel the effects of sea level rise, but in this chapter, we tell the stories of a few that are most immediately and tragically vulnerable. It's a cruel irony that many of these societies, for the most part non-industrial, have played almost no role in the global warming that lies behind so much of current sea level rise; in that sense, they are truly innocent victims of the industrialized world.

Arctic Islands: Abandoning a Sinking Ship

The Arctic seaside villages of Alaska are made up mostly of clusters of government-issue small homes. Houses there are tightly closed and heavily insulated with vestibules between outer and inner doors to prevent the extreme Arctic cold from penetrating the house when someone opens the outer door. These houses stand in sharp contrast to the thatched-roof dwellings perpetually open to the ocean breezes on the atolls of the South Pacific that are also in danger from sea level rise.

Satellite measurements show that the level of the sea is rising in the Arctic Ocean, but that's only part of the problem facing these high-latitude shoreline dwellers. In earlier times, Arctic islands were completely protected from the ocean by ice for most of the year. Because of warming atmospheric and oceanic temperatures, ice-free conditions—normally only two to three months in extent—have lengthened to four and even five months along the North Slope of Alaska and even longer along the shores of the Chukchi and Bering seas to the south. Longer ice-free periods subject the shoreline day after day to the high waves associated with fall and winter storms.

Summertime melting of permafrost (permanently frozen and therefore solid ground) underlying shoreline bluffs and beaches compounds the problem: melting of the ice effectively removes the cement that made the beach a natural seawall and thus greatly facilitates erosion at the shoreline. Add an ever-rising sea level to this picture and the situation becomes dire indeed.

Two Alaskan shoreline villages that have garnered considerable attention are Kivalina and Shishmaref. Kivalina is an eight-mile-long (13 km) Arctic barrier island northwest of Kotzebue in the Chukchi Sea. This community of four hundred was originally a winter encampment for Inupiat Eskimos but is now inhabited year-round. Besides a rapidly receding shoreline on both sides of the island, the village suffers from serious local river pollution emanating from the Red Dog zinc mine, located up the Kivalina River on the mainland. The villagers have filed a lawsuit against the Environmental Protection Agency (EPA) claiming the agency is not enforcing clean water regulations; ironically, the mine itself is on Native Corporation land.

Shishmaref, also on the shores of the Chukchi Sea, is located just south of the Arctic Circle. There are 580 people in this subsistence village located on 4-mile-long (6 km) Sarichef Island, one of the islands that make up the Shishmaref barrier island chain.

A close look at Shishmaref's options and deliberations can give us some perspective on many of the issues that will confront island beachfront communities everywhere in the uncertain future of global change. For Shishmaref, the future is now; and for the hundreds of other beachfront communities on barrier islands from Maine to Texas, and around the world, the future is not far off.

The plight of Shishmaref has attracted global attention. In fact, it has become the poster child of the Arctic global change and sea level rise problem. Since 2002, more than sixty-five media crews from as far away as Sweden and Japan have come to the relatively remote island. Its particular attractiveness to the media may come from a combination of relatively easy access by small plane from Nome or Kotzebue and the welcoming presence of Tony Weyiouanna, community transportation manager and a spokesperson of exceptional skill.

Shishmaref is a village of contrasts. During a February 2007 visit to the village, accompanied by Alaskan geologist Owen Mason, we entered our rented house through a heat-saving vestibule and stepped past a freshly killed white Arctic hare on the floor. A recently skinned and frozen reindeer carcass hung over the balcony on the front of the house. The house had no running water, and the toilet consisted of a large pail in a bathroom. But the