Millions projected to be at risk from sea-level rise in the continental United States

In terms of sheer number of people living in harm’s way [South Florida] is way at the top basically. It just pops out.

Jason Evans, Stetson University ecologist and one of three co-authors of the study

• Finds that the number of people threatened by rising seas fueled by climate change in the U.S. could be three times greater than previously estimated, with more than six million Floridians at risk under a worst-case scenario
• States that few studies have accounted for ongoing population growth when assessing the potential magnitude of future sea level rise impacts
• Addresses this issue by coupling a small-area population projection with a SLR vulnerability assessment across all United States coastal counties
• Finds that a 2100 SLR of 0.9 m places a land area projected to house 4.2 million people at risk of inundation, whereas 1.8 m affects 13.1 million people—approximately two times larger than indicated by current populations
• Results suggest that the absence of protective measures could lead to US population movements of a magnitude similar to the twentieth century Great Migration of southern African-Americans
• States that the population projection approach used can be readily adapted to assess other hazards or to model future per capita economic impacts