As sea levels rise, the East Coast is also sinking

Enlarge / Chesapeake Bay is subsiding up to 5 millimeters a year, greatly exacerbating sea-level rise. It’s a growing problem up and down the Atlantic coast. (credit: Marli Miller/Getty Images)

Climate scientists already know that the East Coast of the United States could see around a foot of sea-level rise by 2050, which will be catastrophic on its own. But they are just beginning to thoroughly measure a “hidden vulnerability” that will make matters far worse: The coastline is also sinking. It’s a phenomenon known as subsidence, and it’s poised to make the rising ocean all the more dangerous, both for people and coastal ecosystems.

New research published in the journal Nature Communications finds that the Atlantic coast—home to more than a third of the US population—is dropping by several millimeters per year. In Charleston, South Carolina, and the Chesapeake Bay, it’s up to 5 millimeters (a fifth of an inch). In some areas of Delaware, it’s as much as twice that.