Estimated sea level rise (SLR) net migrants (in-migrants minus out-migrants) for counties and core based statistical areas under the 1.8 m SLR scenario and no adaptation. Core based statistical areas. This graphic considers only counties located in Core Based Statistical Areas (CBSAs). Counties and CBSAs without expected SLR in-migration are in white. States are abbreviated to standard two-letter codes. Graphic: Hauer, 2017 / Nature Climate Change

By Jake Ellison
20 April 2017 (Seattle PI) – Whether humans, especially those living in America, will do anything to reduce global warming and salvage some of the world’s ice — as well as keep the oceans cooler so they don’t swell too darn much — remains to be seen. But, as of right now, the seas are forecast to rise as much as six feet by 2100, and we all need to think about what that means and begin planning. Coastal cities are already drawing up plans to mitigate higher sea levels, but a new study shows that inland, landlocked cities and towns will have to deal with a flood of their own … not water but people. By 2100, sea water could push some 13.1 million Americans from 319 coastal counties. “I find that unmitigated (sea level rise) is expected to reshape the U.S. population distribution, potentially stressing landlocked areas unprepared to accommodate this wave of coastal migrants — even after accounting for potential adaptation,” writes Mathew Hauer in the study published in Nature Climate Change. To get a fix on where those people might go, Hauer used current IRS data of where people move to establish current routes of migration and then built in other factors such as infrastructure adaption. Under his analysis, Seattle picks up an extra 92,062 folks, while San Francisco loses some 252,450 people. The hardest-hit metro area in the country is, of course, the Miami-Fort Lauderdale-West Palm Beach zone. This part of Florida will lose more than 2 million people, even with rigorous adaptation efforts. Texas gains the most humans on the run: Nearly 1.5 million. The Austin-Round Rock area alone is likely to need space for 818,938 more. [more]

Study: Seattle grows, San Francisco declines with climate change migration

ABSTRACT: Many sea-level rise (SLR) assessments focus on populations presently inhabiting vulnerable coastal communities1, 2, 3, but to date no studies have attempted to model the destinations of these potentially displaced persons. With millions of potential future migrants in heavily populated coastal communities, SLR scholarship focusing solely on coastal communities characterizes SLR as primarily a coastal issue, obscuring the potential impacts in landlocked communities created by SLR-induced displacement. Here I address this issue by merging projected populations at risk of SLR1 with migration systems simulations to project future destinations of SLR migrants in the United States. I find that unmitigated SLR is expected to reshape the US population distribution, potentially stressing landlocked areas unprepared to accommodate this wave of coastal migrants—even after accounting for potential adaptation. These results provide the first glimpse of how climate change will reshape future population distributions and establish a new foundation for modelling potential migration destinations from climate stressors in an era of global environmental change.

Migration induced by sea-level rise could reshape the US population landscape