Millions of Americans at risk of flooding as sea levels rise

The seas are creeping higher as the planet warms. But how high will they go? In Bermuda and the Bahamas, researchers have gone looking for answers; By pinpointing where shorelines stood during a warm period 400,000 years ago, they hope to narrow the range of projections. After correcting for apparent sinking of the islands, the authors of a new study estimate the seas rose 20 to 43 feet higher than today — far less than previous estimates, but still drastic.

Nearly four million Americans, occupying a combined area larger than the state of Maryland, find themselves at risk of severe flooding as sea levels rise in the coming century, new research suggests. Researchers say that with so many communities concentrated on US coasts, the odds for major storm damage get bigger every year.