CHARLOTTE, N.C. — This summer the North Carolina Senate passed a bill banning researchers from reporting predicted increases in the rate of sea level rise. But the ocean, unbound by legislation, is rising anyway — and in North Carolina this rise is accelerating, researchers reported here yesterday (Nov. 6) at the annual meeting of the Geological Society of America.
On the coast of North Carolina and at other so-called "hotspots" along the U.S. East Coast, sea levels are rising about three times more quickly on average than they are globally, researchers reported during a session devoted to sea level rise.
That's the fastest rise in the world.
"What we're seeing here is unique," said Asbury Sallenger, an oceanographer at the U.S. Geological Survey in St. Petersburg, Fla.
The accelerating rise
And this rise is accelerating, said Tal Ezer, a researcher at Old Dominion University in Norfolk, Va.
His colleague, Larry Atkinson, said computer models suggest that if this acceleration continues at the same pace, the rise along the East Coast — from North Carolina to Massachusetts — could be 5.3 feet (1.6 meters) by 2100.
Sea levels on this stretch of land have climbed as much as 1.5 inches (3.7 centimeters) per decade since 1980, while globally they've risen up to 0.4 inches (1.0 cm) per decade, according to a study by Sallenger published in June.
Why is the rise accelerating? Researchers said it's due in part to the sinking of land in the mid-Atlantic, a process called subsidence. Also, warming oceans have decreased the flow rate of the Gulf Stream, a current that ferries warm water from the Caribbean and Gulf of Mexico northeast across the Atlantic. With a less intense Gulf Stream, water is backed up toward the shore, causing sea level rise. Differences in coastal geography, temperature and salinity (salt content) cause different rates of rise along the East Coast, Atkinson said.
Sea levels worldwide are rising due to melting of glaciers in the Arctic and Antarctic, as well as expansion of water caused by heating, researchers said. [8 Ways Global Warming Is Already Changing the World] More
