Jeffrey Peterson

A Changing Climate Means A Changing Society. The Island Press Urban Resilience Project, Supported By The Kresge Foundation And The JPB Foundation, Is Committed To A Greener, Fairer Future.​ This Article Was Originally Published January 7, 2020 in U.S. News and World Report.

In the last democratic presidential debate, Minnesota Sen. Amy Klobuchar fielded a question about whether rising seas and other climate change risks would force cities to move. "I very much hope we're not going to have to relocate entire cities," she responded. Most Americans would agree that coastal cities are simply too big to move and thus will stay pretty much where they are, perhaps with fortified sea walls or some modest retreat from the lowest ground.

Could that change? Might there come a day when some coastal cities decide that fighting to stay, come hell or high water, is simply not a sustainable strategy? It is hard to imagine, but there are several factors that may eventually shift thinking from staying at any cost to moving at a high cost.

Climate change is delivering a one-two punch of more severe storms and rising seas to coastal cities. In 2017, three major storms – Hurricanes Harvey, Irma and Maria – generated some $265 billion in damages and more than 3,000 deaths. Scientists predict that coastal storms will become more intense, bringing widespread flooding as a result of higher storm surges.

A warmer climate is also melting glaciers and ice sheets and accelerating the rate of sea level rise. Unlike storm flooding, the coastal flooding that comes with rising sea levels occurs everywhere and comes to stay. Globally, sea levels are likely to rise between 1 and 4 feet by 2100 and could rise by as much as 8 feet in a worst-case scenario. And seas will keep rising for several centuries after 2100, with as much as 30 feet possible by 2200.

American coastal cities face varying degrees of risk from storms and rising seas over the decades and centuries to come. Also varied are the financial resources available to pay for response actions. What people in all these cities have in common is a strong attachment to the place they call home. Not only do people want to stay, coastal cities represent huge investments in public infrastructure and private property and the logistics and costs of moving are daunting.

Today, the common experience with coastal flooding is that water rises due to a storm and then retreats. Damages are repaired and rebuilding can begin, perhaps with elevated structures and hardened defenses. It is human nature to want to repair and replace homes or communities lost to random acts of nature.

In the decades ahead, the coastal flood experience will change as rising sea levels push more severe storms farther inland and permanently inundate some coastal areas. Permanent inundation could make rebuilding on the old site impractical from the point of view of utilities, emergency services and daily living. As coastal flooding is recognized as permanent inundation, the determination to rebuild at the same location will fade.

At the same time, sea walls and other structures built to provide protection from rising waters come with big limitations. Although sea walls have a reassuring quality of engineered permanence, getting the size right is hard. Bigger sea walls will work longer but cost much more. And, a sea wall can work for a time, but in the long term, even a monster sea wall will not be enough to save some cities.

As major coastal protection projects take a larger and larger share of city budgets, other city services, such as schools, transportation and housing may suffer and quality of life decline. The high costs and foregone services that come with these projects will force governments to make hard decisions about which areas to protect. Areas with high property values might look like the best investment, but low-income communities may strongly object to being offered less or no protection.

It seems likely that, faced with costs of building ever-higher sea walls to protect everyone, even the wealthiest cities will seek help from the federal government. With requests for major funding from rich and poor communities, the federal government will need to decide where and how to spend limited funds. Given that sea walls are often at best a temporary solution, federal taxpayers may be wary of major investments.

Federal taxpayers may be circumspect of more than costs. Structural protection projects for big cities will need to be coordinated with neighboring communities with fewer resources. Without a coordinated approach to the shape of the coastline, it is hard to maintain efficient transportation networks and other infrastructure. Decisions about how to support inland migration of beaches and wetlands as sea level rises become more complicated.

Unsatisfactory experiences with structural protection may make the idea of moving look a bit more attractive. Having a good plan for where to relocate might make moving look even better.

A new place should not just be safer, it should feel like home. American coastal cities are rich in culture and diverse communities. This social capital – the heart and spirit of a city – need not be lost even if the physical infrastructure is left to rising waters. A key challenge for the future is developing creative ways to transfer the social capital of coastal cities to safer locations.

The obstacles to moving even part of a major city to safer ground are legion. In addition to saving the heart and spirit of a community, a new location must be found, the nuts and bolts of infrastructure and utilities need to be designed, property rights must be considered, and the interests of neighboring communities and ecosystems need to be addressed. The financial costs are intimidating, although likely less in the long run than failed sea walls followed by inundation.

Microsoft Corporation is famous for asking job applicants, "How would you move Mount Fuji?" The question suggests that there may be answers to impossible-sounding problems and that a first step toward doing the impossible is asking how it might be done. Can a major coastal city successfully relocate to a safer place? We do not know. But, the stakes for America's coastal cities are high and it is time to ask the question.