Worldwide, millions of people live in river deltas that are sinking faster than sea levels are rising, research suggests. This exacerbates the risk of catastrophic coastal flooding and land loss.

Many different countries have long rivers, and the U.S. is no exception, but that river is more complicated and unique than you might have expected.

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. River deltas around the ...