Sea levels rising on US East Coast much faster than global average (+video)

The USGS study suggests the Northeast would get hit harder because of ocean currents. When the Gulf Stream and its northern extension slow down, the slope of the seas changes to balance against the slowing current. That slope then pushes up sea levels in the Northeast. It is like a see-saw effect, Sallenger theorizes.

Scientists believe that with global warming, the Gulf Stream and other ocean currents are slowing and will slow further, Sallenger said.

Jeff Williams, a retired USGS expert who wasn't part of the study, and Stefan Rahmstorf, a professor of ocean physics at the Potsdam Institute in Germany, said the study does a good job of making the case for sea level rise acceleration.

Margaret Davidson, director of the Coastal Services Center for the National Oceanic and Atmospheric Administration in Charleston, South Carolina, said the implications of the new research are "huge when you think about it. Somewhere between Maryland and Massachusetts, you've got some bodaciously expensive property at risk."

Sea level projections matter in coastal states because flood maps based on those predictions can result in restrictions on property development and affect flood insurance rates.

Those estimates became an issue in North Carolina recently when the Legislature proposed using historic figures to calculate future sea levels, rejecting higher rates from a state panel of experts. The USGS study suggests an even higher level than the panel's estimate for 2100.

The North Carolina proposal used data from University of Florida professor Robert Dean, who had found no regional differences in sea level rise. Dean said he can't argue with the results from Sallenger's study showing accelerating sea level rise in the region, but he said it's more likely to be from natural cycles. Sallenger said there is no evidence to support that claim.

[Editor's note: An earlier headline mischaracterized the sea level rise. The study found that the seas on the East Coast are have been rising at an annual rate three times to four times faster than the global average.]

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Associated Press writers Allen Reed in Raleigh, North Carolina, and Jeff Barnard in Grants Pass, Oregon, contributed to this report.

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