Category Archives: Sea Level Rise

Barrier islands and sea-level rise

Orrin Pilkey Barrier Islands

By Orrin H. Pilkey, Professor Emeritus of Earth Science at Duke University’s Nicholas School of the Environment.

It had to happen. As more and more buildings are built along the North Carolina shoreline and as shoreline-retreat catches up with these buildings (many of which are rentals), the pressure to bend the coastal regulations to save buildings becomes almost unbearable. But maintaining the shoreline status quo and protecting all buildings eventually means loss of our developed beaches. It also means we will be ill- prepared for sea-level rise.

Currently in North Carolina sea level is rising about 1.5 feet per century over a land slope that averages 1: 2000. This means a 1-foot rise could cause a shoreline retreat of more than a third of a mile (in theory). Already some of the erosion on our shoreline is due to sea-level rise, which explains why a spring high tide flooded N.C. 12 last year near Rodanthe.

Over the next 100 years, according to recent estimates by Professor Hal Wanless of the University of Miami, we should expect 5 to 6 feet of sea-level rise. This is close to the North Carolina sea-level rise panel’s maximum estimate of 4.6 feet over the same time frame. The Wanless projection is a bit more up-to-date because it considers a whole series of warming events related to disappearing sea ice in the Arctic Ocean that may contribute 1 foot of rise.

Projections of the rise by scientists and government agencies are always on a century basis, but our problems will arise much quicker than that. To put this into a practical context, a 2- to 3-foot rise, which may be reached as soon as 40 to 60 years from now, means the end of barrier island development.

Why? Erosion rates will be even faster than at present, and “nourished” beaches will no longer stay put. Our barrier islands will have to be surrounded in their entirety by seawalls to protect them from storm waves and inundation. At the same time funding for local beach communities is in doubt, because protecting major coastal cities and infrastructure will be a higher government priority.

Here in North Carolina, efforts to preserve our beaches climaxed when the Coastal Resources Commission ordered sandbags removed a couple of years ago. Sandbags are no different than concrete walls in terms of the erosion they cause to a beach (take a walk or drive along Seagull Drive on South Nags Head for an example). Shortly after the sandbag removal order was issued, however, a moratorium on it was declared, and was renewed this year.

At the same time the beachfront communities, especially exclusive Figure Eight island, began pushing for terminal groins (jetties) against the advice of the state’s marine geology and oceanography community.

Terminal groins and sandbags aren’t the only problems. The proposed new Oregon Inlet bridge assures that the state will face long and costly decades of holding an island in place solely to protect a single road. High-rises continue to be built on various barrier islands, effectively preventing any sort of flexible response to the rising sea.

Now is not the time to drop the ball. Global change is already upon us.

North Carolina needs to preserve the regulations that have served us well for decades. This includes removal of sandbags as regulations require. We need to go further and prohibit all high-rises on any barrier island. And when the time comes, we must accept that buildings that can no longer be protected through reasonable means must be demolished or moved back.

If we don’t do these things we eventually will be Florida-ized. That state has hundreds of miles of shorefront lined with high-rises protected by beach-destroying seawalls. This type of shortsighted barrier island development has a dismal future 40 years from now.

North Carolina’s coastal management program needs more backbone now than ever before. Gov. Beverly Perdue is about to appoint new members of the CRC. If the new appointees maintain the status quo and continue to protect all beachfront development, the state’s beaches will continue their downward plunge. Perdue should take the long view.

Original Article


Op Ed, The Rising Sea, Orrin Pilkey and Rob Young

By Orrin H. Pilkey, Professor Emeritus of Earth Science at Duke University’s Nicholas School of the Environment.

Tuesday, August 25, 2009

What little serious attention that has been paid to the rising sea level in North Carolina has mainly focused on the beaches and barrier islands and the threat to beachfront Mcmansions. But sea level rise is a major threat to the lands behind the barrier islands, to the towns and villages scattered about and especially to the states agricultural industry.

In our new book, The Rising Sea, we suggest that coastal areas can expect a minimum of 3 feet of sea level rise by the year 2100. This is made all the more significant because the average slope of the land in the lower coastal plain of North Carolina is 1 to 2000 meaning that a sea level rise of 1 foot will move the shoreline back 2000 feet. The slope of the mainland behind Pamlico and Albermarle Sounds however is typically 1 to 10,000 and even less, meaning that a 1 foot rise will flood more than 2 miles inland.

A number of small towns along the sounds and estuaries will be impacted. If you can see a marsh from your town you may be in trouble. Some like Plymouth, Washington and Columbia are entirely at low elevations and could be completely inundated by a 3 foot rise. Dozens of other small towns and even Wilmington will soon find their storm drainage systems and sewage plants in need of replacement.

But mainland flooding is only part of the problem. Storm surges from future Hurricanes and northeasters as well as spring tides will intrude ever further into the mainland as seas rise. Salt water intrusion will occur both into the groundwater and up the rivers and streams and render much agricultural land completely useless. River floods will increase in magnitude as the rising sea level provides a higher base level at the river mouth. As sea level inches up, the efficiency of drainage from many farmers fields will decrease and water logging will be prolonged. As the ground water table moves up the roots of certain tree species will be flooded and large scale killing of forests will occur even before salinization. Already too many trees are dying from this cause along estuarine shorelines in NC.

Shoreline erosion along estuarine shorelines will increase and since restrictions on shoreline stabilization on such shorelines are effectively non-existant in NC. Sea walls will sprout leading eventually to widespread loss of salt marshes.

All of these things are already happening on a small scale in our lower coastal plain. Salt water is extending ever further up rivers, salt water is intruding ion some areas and fields are draining more poorly than a decade ago.

There aren’t many things that can be done to mitigate the serious damage that will be caused to agriculture in North Carolina’s lower coastal plain. Perhaps the most likely to succeed at least temporarily would be changing to crops that are more resistant to a higher water table. A more costly and also temporary approach would be to increase the efficiency of field drainage by excavating new ditches and even installing pumps. Levee construction is already being carried out for a number of small towns (such as Swan Quarter) but this most likely wont work for agricultural areas. Installing gates at river or inlet mouths in Dutch-like fashion is clearly out of the question because of the huge costs involved. Its important to remember when North Carolina farmers are in trouble so will also be the farmers all along the East Coast and Gulf coast coastal plain from New Jersey to Texas. Considering that the cities such as New York, Boston and Philadelphisa will be in trouble it is likely that government help to solve the problem will not be impressively large.

North Carolina has instituted a new sea level rise panel to examine the impact of sea level rise. We hope the fate of thousands of beach cottages wont overshadow the future of North Carolina lower coastal plain farmers. They are important too.

In Low-Lying Bangladesh, The Sea Takes a Human Toll

flood-bangladesh
Too wet to live on. One of the flood victims in Bangladesh shows the ground of his hut that is yet unlivable.Captions and Photo source: ©© Amio James Ascension

Excerpts;

Jonathan Bjerg Møller, 2 videos: “Aila’s Victims” and “Wahidul’s Story.”

Danish photographer and filmmaker Jonathan Bjerg Møller recently spent nine months in Bangladesh, chronicling the lives of people struggling to survive just a few feet above sea level…

Read Full Article And Watch Video, Yale E360

Sea Level to Rise Even With Aggressive Geo-Engineering

waves-storm-coastal-care
Photograph: © SAF — Coastal Care

Excerpts;

New findings by international research group of scientists from England, China and Denmark just published suggest that sea level will likely be 30-70 centimetres higher by 2100 than at the start of the century even if all but the most aggressive geo-engineering schemes are undertaken to mitigate the effects of global warming and greenhouse gas emissions are stringently controlled…

Read Full Article, Science Daily

Proceedings of the National Academy of Sciences
Excerpt published August 23 in the journal PNAS Proceedings of the National Academy of Sciences, Efficacy of geoengineering to limit 21st century sea-level rise..

Kingscliff Battles Beach Erosion, Australia

coastal-erosion
Coastal erosion. Photograph: © SAF — Coastal Care

Excerpts

Two months ago, photographer Tania Phillips stood where the Cudgen Creek meets the Pacific Ocean at Kingscliff on the far north coast and noticed that the beach was washing away.

Kingscliff residents fear their idyllic seaside village may never be restored to its former glory after the besieged coastline copped a further battering this week…

Read Full Article, Gold Coast News

Watch a Slideshow, Science Daily

Erosion doubles along Alaska’s Arctic coast:: Cultural and Historical Sites Lost

alaska-erosion-usgs
A cabin along the Arctic Alaska coastline was recently washed into the ocean because the bluff it was sitting on top of was eroded away. Captions and Photo source: ©© Benjamin Jones, USGS

Excerpt, from USGS.

Coastal erosion has more than doubled in Alaska, up to 45 feet per year, in a 5-year period between 2002 and 2007 along a 40-mile stretch of the Beaufort Sea. A U.S. Geological Survey-led study reveals that average annual erosion rates along this part of the Beaufort Sea climbed from historical levels of about 20 feet per year between the mid-1950s and late-1970s, to 28 feet per year between the late-1970s and early 2000s, to a rate of 45 feet per year between 2002 and 2007. The study was published in the February,18th 2009 issue of Geophysical Research Letters, a publication of the American Geophysical Union.

USGS scientist and lead author Benjamin Jones cautioned that it is possible that the recent patterns documented in their study may represent a short-term episode of enhanced erosion. However, they may well represent the future pattern of coastline erosion in the Arctic. “Erosion of coastlines is a natural process, and this segment of coastline has historically eroded at some of the highest rates in the circum-Arctic, so the changes occurring on this open-ocean coast might not be occurring in other Arctic coastal settings,” said Jones.

The authors proposed that these recent shifts in the rate and pattern of land loss along this coastline segment are potentially a result of changing arctic conditions, including declining sea ice extent, increasing summertime sea-surface temperature, rising sea level, and increases in storm power and corresponding wave action.

“Taken together, these factors may be leading to a new era in ocean-land interactions that seem to be repositioning and reshaping the Arctic coastline,” wrote Jones and his colleagues. “And any increases in the current rates of coastal retreat will have further ramifications on Arctic landscapes – including losses in freshwater and terrestrial wildlife habitats, and in disappearing cultural sites, as well as adversely impacting coastal villages and towns. In addition, oil test wells are threatened.”

Alaska Coastal Erosion2

In fact, in another recent study along the same stretch of the Beaufort Sea, Jones and his co-authors verified “disappearing” cultural and historical sites, including Esook, a turn-of-the-century trading post now part of the Alaskan seafloor and Kolovik (Qalluvik), an abandoned Inupiaq village site that may soon be lost. At another site, near Lonely, Alaska, Jones snapped a picture of a wooden whaling boat that had rested on a bluff overhanging the ocean for nearly a century. A few months later the boat had washed away to sea. This study was published in the journal Arctic.

Understanding contemporary erosion rates is important because Arctic climate change is leading to rapid and complex environmental responses in both terrestrial and marine ecosystems in ways that will almost certainly affect the rate and pattern of coastline erosion in the Arctic, the authors wrote. “For example,” said Jones, “the recent trends toward warming sea-surface temperatures and rising sea-level may act to weaken the permafrost-dominated coastline by ‘helping’ more quickly thaw ice-rich coastal bluffs and may potentially explain the disproportionate increase in erosion along ice-rich coastal bluffs relative to ice-poor coastal bluffs that we documented in our study.”

The authors also documented sections of coastline that eroded more than 80 feet during 2007. Interestingly, there were no westerly storm events during the summer of 2007, traditionally believed to be the drivers of coastal erosion in this region the Arctic. However, 2007 did boast the minimum arctic sea-ice extent on record and relatively warm ocean temperatures. The authors emphasized that monitoring of coastal erosion should continue to better understand the causes for these heightened erosion rates, particularly as Arctic regions are being targeted for additional hydrocarbon development.

Alaska Coastal Erosion

Original Article And Learn More, USGS

Climate change threatens life in Shishmaref, Alaska; CNN
“When the arctic winds howl and waves pummel the shore of this Inupiat Eskimo village, Shelton and Clara Kokeok fear that their house, already at the edge of the Earth, finally may plunge into the gray sea below. “The land is going away,” said Shelton Kokeok, 65, whose home is on the tip of a bluff that’s been melting in part because of climate change. “I think it’s going to vanish one of these days.”
A dozen Alaskan villages, including Shishmaref, are at some stage of moving because of climate-change-related impacts like coastal erosion and flooding…Around the world, as many as 150 million people may become “climate refugees” because of global warming, according to an Environmental Justice Foundation report, which attributes some of the moves to rising sea levels…”

Alaska Coastal Erosion
Photo source: USGS

Indian Ocean Sea Level Rise Threatens Millions

Indian Ocean
This image shows the key player in the process, the Indo-Pacific warm pool, in bright orange. This enormous, bathtub-shaped area spans a region of the tropical oceans from the east coast of Africa to the International Date Line in the Pacific. The warm pool has heated by about 1 degree Fahrenheit, or 0.5 degrees Celsius, in the past 50 years, primarily because of human-generated emissions of greenhouses gases.I mage Source: NASA Earth Observatory

Excerpts;

Newly detected rising sea levels in parts of the Indian Ocean, including the coastlines of the Bay of Bengal, the Arabian Sea, Sri Lanka, Sumatra and Java, appear to be at least partly a result of human-induced increases of atmospheric greenhouse gases, says a study led by the University of Colorado at Boulder.

The study, which combined sea surface measurements going back to the 1960s and satellite observations, indicates anthropogenic climate warming likely is amplifying regional sea rise changes in parts of the Indian Ocean, threatening inhabitants of some coastal areas and islands, said CU-Boulder Associate Professor Weiqing Han, lead study author. The sea level rise, which may aggravate monsoon flooding in Bangladesh and India, could have far-reaching impacts on both future regional and global climate.

The key player in the process is the Indo-Pacific warm pool, an enormous, bathtub-shaped area of the tropical oceans stretching from the east coast of Africa west to the International Date Line in the Pacific. The warm pool has heated by about 1 degree Fahrenheit, or 0.5 degrees Celsius, in the past 50 years, primarily caused by human-generated increases of greenhouse gases, said Han…

Read Full Article, Science Daily

Article in, UC Arts and Sciences Magazine

A 500 million euros Plan to strengthen levees in France


Seawall, Courseulles-sur-mer, Basse Normandie. Photo source: ©© Olivier Engel

Un plan de 500 millions d’euros pour consolider les digues en France.

By Bertrand d’Armagnac, Le Monde.

Quatre mois et demi après la catastrophe provoquée par la tempête Xynthia en Vendée et en Charente-Maritime, le Gouvernement a annoncé ce mardi 13 juillet, la mise en place d’un “plan digues” destiné à mieux répondre aux risques de crues et d’inondations en France.

Présenté ce mardi en Conseil des ministres par le ministre du Développement durable, Jean-Louis Borloo, ce plan prévoit le renforcement de 1200 kilomètres de digues fluviales et maritimes.

Sur la période 2011-2016, l’Etat souhaite mobiliser environ 500 millions d’euros afin d’aider au confortement de 1 200 km de digues sur un parc de près de 9 000 km. Le plan, dont la mise en place est prévue dès 2010, fera l’objet, dans les mois à venir, d’une concertation visant à l’enrichir et à le préciser. Il reprend notamment des pistes lancées lors des auditions devant le Parlement, sur les causes de la tempête Xynthia.

Read Original Article, Le Monde


A plan of 500 million euros to strengthen the levees in France.
Google English Translation

Four and a half months after the disaster caused by storm Xynthia in the Vendée and Charente-Maritime, the French Government presented Tuesday, July 13, in Council of Ministers, proposals for the development of a “Plan Digues” intended to better respond to flood risk and flooding in France.

Over the period 2011-2016, the State wants to raise about 500 million euros to aid in reinforcement of 1,200 km of sea walls and levees, on a fleet of nearly 9000 km. The plan, whose implementation is planned from 2010, will be in the coming months, an action designed to enrich and to clarify that. It includes such tracks launched at the hearings before the Parliament on the causes of the storm Xynthia.

“The state of protection works, overall concern and the lack of a suitable project management, pose real problems today,” said French Minister of Ecology, Francois Borloo. The system devised by the Department of Ecology take into consideration sea walls and levees along coastlines and rivers, as well as the natural lines of defense such as dunes, lagoons and swamps.

It encompasses not only the upgrading of the park dykes and restructuring of its management, but also reducing the vulnerability of areas at risk and better use of weather forecasting and warnings.

The plan to establish by 2011 a list of high-risk flood areas, identified as priorities, which will trigger the diagnosis and the securing of levees and natural systems involved. However, certain protective structures require urgent action and therefore the initiation of work before the spring tides in August and September. This is the case of dams damaged by the storm Xynthia who are already the subject of work launched in March, which should lead to a consolidation before reliable high tides.

For other works, the identification process is being completed in respect of river levees, and will be completed by the end of 2010. The diagnostic techniques for detecting the most dangerous structures will be established by end-2010 for all works damaged by Xynthia and before the end of 2011 for the entire coastline. This diagnostic work will be done on the sea walls and levees between late 2010 and late 2011.

The organization of project management is another issue to be addressed urgently. In France, almost one third of the sea walls has no known owner or is in the hands of local residents or municipalities with insufficient means.

Devices are to be found in order to ensure that sea walls’ maintenance and repairs are completed specifically when faced with owners with reduced technical and financial capabilities, or if they are unknown. A working group of State and local Governments Representatives, is to make proposals on this topic by the end of 2010, including a better definition of the legal framework for community response.

Another element of the Plan: the urbanization of areas at high risk. A greater control of these areas, including the ban on further construction in low-lying areas, is now recommended by the Ecology Minister. In order to manage urbanization, plans to prevent natural hazards (NRPP) will be completed or be reviewed within a maximum period of three years.

How High Will Seas Rise? Get Ready for Seven Feet

Sea Level Rise Glacier

By Robert Young and Orrin Pilkey.

The reports from the Intergovernmental Panel on Climate Change (IPCC) are balanced and comprehensive documents summarizing the impact of global warming on the planet. But they are not without imperfections, and one of the most notable was the analysis of future sea level rise contained in the latest report, issued in 2007.

Given the complexities of forecasting how much the melting of the Greenland and West Antarctic ice sheets will contribute to increases in global sea level, the IPCC chose not to include these giant ice masses in their calculations, thus ignoring what is likely to be the most important source of sea level rise in the 21st century. Arguing that too little was understood about ice sheet collapse to construct a mathematical model upon which even a rough estimate could be based, the IPCC came up with sea level predictions using thermal expansion of the oceans and melting of mountain glaciers outside the poles. Its results were predictably conservative — a maximum of a two-foot rise this century — and were even a foot lower than an earlier IPCC report that factored in some melting of Greenland’s ice sheet.

The IPCC’s 2007 sea level calculations — widely recognized by the academic community as a critical flaw in the report — have caused confusion among many in the general public and the media and have created fodder for global warming skeptics. But there should be no confusion about the serious threat posed by rising sea levels, especially as evidence has mounted in the past two years of the accelerated pace of melting of the Greenland and West Antarctic ice sheets.

The message for the world’s leaders and decision makers is that sea level rise is real and is only going to get worse. Indeed, we make the case in our recent book, The Rising Sea, that governments and coastal managers should assume the inevitability of a seven-foot rise in sea level. This number is not a prediction. But we believe that seven feet is the most prudent, conservative long-term planning guideline for coastal cities and communities, especially for the siting of major infrastructure; a number of academic studies examining recent ice sheet dynamics have suggested that an increase of seven feet or more is not only possible, but likely. Certainly, no one should be expecting less than a three-foot rise in sea level this century.

In the 20th century, sea level rise was primarily due to thermal expansion of ocean water. Contributions of melting mountain glaciers and the large ice sheets were minor components. But most climate scientists now believe that the main drivers of sea level rise in the 21st century will be the melting of the West Antarctic Ice Sheet (a potential of a 16-foot rise if the entire sheet melts) and the Greenland Ice Sheet (a potential rise of 20 feet if the entire ice cap melts). The nature of the melting is non-linear and is difficult to predict.

Melting Ice

Seeking to correct the IPCC’s failure to come up with a comprehensive forecast for sea level increase, a number of state panels and governmentcommittees have produced sea level rise predictions that include an examination of melting ice sheets. For example, sea level rise panels in Rhode Island and Miami-Dade County have concluded that a minimum of a three- to five-foot sea level rise should be anticipated by 2100. A California report assumes a possible 4.6-foot rise by 2100, while the Dutch assume a 2.5-foot rise by 2050 in the design of their tidal gates.

Given the growing consensus about the major sea level rise on the way in the coming century or two, the continued development of many low-lying coastal areas — including much of the U.S. east coast — is foolhardy and irresponsible.

Who is at risk?

Rising seas will be on the front lines of the battle against changing climate during the next century. Our great concern is that as the infrastructure of major cities in the industrialized world becomes threatened, there will be few resources left to address the dramatic impacts that will be facing the citizens of the developing world.

The ramifications of a major sea level rise are massive. Agriculture will be disrupted, water supplies will be salinized, storms and flood waters will reach ever further inland, and millions of environmental refugees will be created — 15 million people live at or below three feet elevation in Bangladesh, for example. Governments, especially those in the developing world, will be disrupted, creating political instability.

The most vulnerable of all coastal environments are deltas of major rivers, including the Mekong, Irrawaddy, Niger, Ganges-Brahmaputra, Nile, andMississippi. Here, land subsidence will combine with global sea level rise to create very high rates of what is known as “local, relative sea level rise.” The rising seas will displace the vast majority of people in these delta regions. Adding insult to injury, in many parts of Asia the rice crop will be decimated by rising sea level — a three-foot sea level rise will eliminate half of the rice production in Vietnam — causing a food crisis coincident with the mass migration of people.

The Mississippi Delta is unique because it lies within a country with the financial resources to fight land loss. Nevertheless, we believe multibillion-dollar engineering and restoration efforts designed to preserve communities on the Mississippi Delta are doomed to failure, given the magnitude of relative sea level rise expected. Former Secretary of the Interior Bruce Babbitt said in 2008 that it was an “ineluctable fact” that within the lifespan of some people alive today, “the vast majority of that land will be underwater.” He also faulted federal officials for not developing migration plans for area residents and for not having the “honesty and compassion” to tell Louisiana residents the “truth”: Someday, they will have to leave the delta. The city of New Orleans can probably be protected into the next century, but only at great expense and with little guarantee that future storms like hurricane Katrina will not inundate the city again.

Sea Level Rise Maldives

Pacific and Indian Ocean atoll nations are already being abandoned because of the direct and indirect effects of sea level rise, such as saltwater intrusion into groundwater. In the Marshall Islands, some crops are being grown in abandoned 55-gallon oil drums because the ground is now too salty for planting. New Zealand is accepting, on a gradual basis, all of the inhabitants of the Tuvalu atolls. Inhabitants of Carteret Atoll have all moved to Papua, New Guinea. The forward-looking government of the Maldives recently held a cabinet meeting underwater to highlight the ultimate fate of their small island nation.

The world’s major coastal cities will undoubtedly receive most of the attention as sea level rise threatens infrastructure. Miami tops the list of most endangered cities in the world, as measured by the value of property that would be threatened by a three-foot rise. This would flood all of Miami Beach and leave downtown Miami sitting as an island of water, disconnected from the rest of Florida. Other threatened U.S. cities include New York/Newark, New Orleans, Boston, Washington, Philadelphia, Tampa-St Petersburg, and San Francisco. Osaka/Kobe, Tokyo, Rotterdam, Amsterdam, and Nagoya are among the most threatened major cities outside of North America.

Preserving coastal cities will require huge public expenditures, leaving smaller coastal resort communities to fend for themselves. Manhattan, for example, is likely to beat out Nags Head, North Carolina for federal funds, a fact that recreational beach communities must recognize when planning a response to sea level rise.

Twelve percent of the world’s open ocean shorelines are fronted by barrier islands, and a three-foot sea level rise will spell doom for development on most of them — save for those completely surrounded by massive seawalls.Impacts in the United States, with a 3,500-mile long barrier island shoreline extending from Montauk Point on Long Island to the Mexican border, will be huge. The only way to preserve the barrier islands themselves will be to abandon them so that they may respond naturally to rising sea level. Yet, most coastal states continue to allow massive, irresponsible development of the low-lying coast.

Ironically, low-elevation Florida is probably the least prepared of all coastal states. Hundreds of miles of high rises line the state’s shoreline, and more are built every year. The state pours subsidies into coastal development through state-run insurance and funding for coastal protection. If a portion of those funds were spent adapting to sea level rise rather than ignoring it, Florida might be ready to meet the challenge of the next century. Let’s hope the state rises to the challenge.

Sea Level Rise

Despite the dire facts, the next century of rising sea level need not be an economic disaster. Thoughtful planning can lead to a measured retreat from vulnerable coastal lowlands. We recommend the following:

Immediately prohibit the construction of high-rise buildings and major infrastructure in areas vulnerable to future sea level rise. Buildings placed in future hazardous zones should be small and movable — or disposable.

Relocation of buildings and infrastructure should be a guiding philosophy. Instead of making major repairs on infrastructure such as bridges, water supply, and sewer and drainage systems, when major maintenance is needed, go the extra mile and place them out of reach of the sea. In our view, no new sewer and water lines should be introduced to zones that will be adversely affected by sea level rise in the next 50 years. Relocation of some beach buildings could be implemented after severe storms or with financial incentives.

Stop government assistance for oceanfront rebuilding. The guarantee of recovery is perhaps the biggest obstacle to a sensible response to sea level rise. The goal in the past has always been to restore conditions to what they were before a storm or flood. In the United States, hurricanes have become urban renewal programs. The replacement houses become larger and larger and even more costly to replace again in the future. Those who invest in vulnerable coastal areas need to assume responsibility for that decision. If you stay, you pay.

Get the Corps off the shore. The U.S. Army Corps of Engineers, more or less by default, is the government agency in charge of much of the planning and the funding for the nation’s response to sea level rise. It is an agency ill-suited to the job. Part of the problem is that the engineers’ “we can fix it” mentality is the wrong mindset for a sensible approach to responding to changing sea level.

Local governments cannot be expected to take the lead. The problems created by sea level rise are international and national, not local, in scope. Local governments of coastal towns (understandably) follow the self-interests of coastal property owners and developers, so preservation of buildings and maintaining tax base is inevitably a very high priority. In addition, the resources needed to respond to sea level rise will be far beyond those available to local communities.

Responding to long-term sea level rise will pose unprecedented challenges to the international community. Economic and humanitarian disasters can be avoided, but only through wise, forward-looking planning. Tough decisions will need to be made regarding the allocation of resources and response to natural disasters. Let us hope that our political leadership can provide the bold vision and strong leadership that will be required to implement a reasoned response.

Article in Yale E