Climate change and sea level rise could put 13.1 million Americans at risk of flooding by 2100, according to a new study in the journal Nature Climate Change.
Nearly half of the at-risk population resides in Florida, and 70 percent in the southeastern United States. Unlike previous assessments that looked only at sea level rise, the study examines both climate and population projections for all 319 coastal U.S. counties over the next century. Three feet of sea level rise puts 4.2 million Americans at risk. Six feet—the high end of estimates by the National Oceanic and Atmospheric Administration—puts 13.1 million at risk. “The impact projections are up to three times larger than current estimates, which significantly underestimate the effect of sea level rise in the United States,” said Mathew Hauer, lead author of the study and a demographer at the University of Georgia.