A man tries to jump to a shallow spot as he crosses a flooded street in Miami Beach, Florida, in September. Photograph: Joe Raedle/Getty Images
Combination of coastal population growth and rising sea levels could drive a shift comparable to the 20th century’s Great Migration
Oliver Milman @olliemilman
Monday 14 March 2016 12.00 EDT Last modified on Thursday 17 March 2016 08.26 EDT
US coastal areas occupied by more than 13 million people will be at risk of being completely swamped by the sea under a worst-case climate change scenario, new research predicts, potentially leading to a population upheaval comparable to the Great Migration of the 20th century.
Population growth in coastal areas over the course of this century, particularly in vulnerable areas of Florida, is likely to collide with the reality of rising seas caused by melting glaciers and thermal expansion as the planet warms.
Research led by the University of Georgia has provided the first glimpse of how demographic changes in America will place greater numbers of people at the frontline of sea level rises. In a severe scenario involving a 6ft (1.8m) rise in sea levels by 2100, fuelled by the gradual collapse of the Antarctic ice sheets, a total of 13.1 million people would risk seeing their homes inundated.
A less dramatic sea level rise of 0.9m, still considered at the upper end of IPCC projections, would risk land occupied by 4.2 million people being claimed by the sea.