Besides the utter devastation of the Bahamas, today we are seeing tragic images of U.S Atlantic coastal flooding from Hurricane Dorian. Flooding that will only become worse as water and air temperatures continue rise from increasing greenhouse gas concentrations.

In a second study, a team of distinguished scientists argues that the US should face the inevitable and begin to plan for a managed, strategic retreat from its own coasts.

At the heart of both studies is a set of new realities imposed by a rapidly-heating ocean and higher air temperatures worldwide. As the icecaps of Greenland and Antarctica melt, and as the glaciers of Canada and Alaska retreat, so sea levels have begun to rise inexorably.

But as the oceans increase in average temperature, thanks to an ever-warmer atmosphere driven by greenhouse gases from profligate combustion of fossil fuels, so the oceans have begun to expand: warmer waters are less dense, and thus higher.

“We need to stop picturing our relationship with nature as a war. We’re not winning or losing, we’re adjusting to changes in nature”
And there is a third factor. With warmer seas there will be more frequent and more violent hurricanes and windstorms, more damaging storm surges and yet more torrential rainfall.

Worse US Atlantic floods need planned retreat by Tim Radford, Climate News Network, September 3rd, 2019

By the century’s end, millions of US citizens could become climate refugees. A study of US counties vulnerable to sea level rise warns that if the coasts are not protected, the movement of people could match the scale of the 20th-century “Great Migration” of African-Americans from the south to the northern states.

Altogether, the new research concludes, more than 13 million people could be affected by a sea level rise of 1.8 metres. This is the high end of climate science projections for sea level rise, but even at the low end a rise of 0.9 metres will put more than 4 million people at risk.

US faces floods of climate refugees by Tim Radford, Climate New Network, March 23rd, 2016

We’re seeing thousands of cars traveling away from the flood zones, both sides of Interstate highways moving in the same direction. It is good to see shelters open for people who have evacuated, and transportation to those shelters in some cases.

Faced with global warming, rising sea levels, and the climate-related extremes they intensify, the question is no longer whether some communities will retreat—moving people and assets out of harm’s way—but why, where, when, and how they will retreat. To the extent that retreat is already happening, it is typically ad hoc and focused on risk reduction in isolation from broader societal goals. It is also frequently inequitable and often ignores the communities left behind or those receiving people who retreat. Retreat has been seen largely as a last resort, a failure to adapt, or a one-time emergency action; thus, little research has focused on retreat, leaving practitioners with little guidance. Such a narrow conception of retreat has limited decision-makers’ perception of the tools available and stilted innovation. We propose a reconceptualization of retreat as a suite of adaptation options that are both strategic and managed. Strategy integrates retreat into long-term development goals and identifies why retreat should occur and, in doing so, influences where and when. Management addresses how retreat is executed. By reconceptualizing retreat as a set of tools used to achieve societal goals, communities and nations gain additional adaptation options and a better chance of choosing the actions most likely to help their communities thrive.

The case for strategic and managed climate retreat, A.R. Siders, Miyuki Hino, Katharine J. Mach
Science 23 Aug 2019: Vol. 365, Issue 6455, pp. 761-763

After the storm passes,it appears these climate refugees get little help to figure out what their next steps should be. The first decision is whether to return and rebuild, or leave. If the decision is to rebuild, houses and communities should be built for the future, with the ability to withstand hurricane force winds, rising water. Serious consideration should be given to the self contained renewable energy generation and storage.

I’ve wondered how wise it was to try to rebuild Puerto Rico after Hurricane Maria. The damage there was not nearly as severe as it is in the Bahamas, where it seems less likely significant rebuilding can, or perhaps should, occur.

“One major challenge with retreat is that we’re so focused on getting people out of harm’s way, we miss the chance to help them move to opportunity.”

The researchers take the long view, noting that retreat may be the answer to climate change in some areas, but it may not be a step that’s necessary this year or even this decade.

“The challenge is to prepare for long-term retreat by limiting development in at-risk areas,” they write, and making plans for further action based on responding to specific triggers and constantly monitoring and evaluating conditions.

“The story of retreat as a climate response is just beginning,” Mach said. “Retreat is compelling because it brings together so many aspects of how societies work, what individuals are trying to achieve and what it takes to ensure preparedness and resilience in a changing climate.”

The paper makes note of a variety of areas where additional work is needed, including coordination of various levels of government and support for relocation assistance programs. First, Siders said, communities must identify which areas they most want to protect and how to encourage and assist relocation.

“Managed retreat needs to be embedded in larger conversations and social programs,” she said. “Retreat can’t be just about avoiding risk. It needs to be about moving toward something better.”

The case for strategic and managed climate retreat, A.R. Siders, Miyuki Hino, Katharine J. Mach
Science 23 Aug 2019: Vol. 365, Issue 6455, pp. 761-763