Sea’s rise may prove the greater in Northeast

In the debate over global warming, one thing is clear: as the planet gets warmer, sea levels will rise. But how much, where and how soon? Those questions are notoriously hard to answer.

Scientists at the National Center for Atmospheric Research, in Boulder, Colo., are now adding to the complexity with a new prediction. If the melting of Greenland’s ice sheets continues to accelerate, they say, sea levels will rise even more in the northeastern United States and Maritime Canada than in other areas around the world.

The researchers, Aixue Hu and Gerald A. Meehl, based their predictions on runoff data from Greenland and an analysis of ocean circulation patterns.

They said that if Greenland melting continued to accelerate, it would alter ocean currents in a way that sends warmer water toward the northeastern and Maritime coasts. Because water expands as it warms, this influx of warmer water would raise sea levels as much as a foot or two more than in other coastal regions by the end of the century.

These rises in sea level, if they occur, would be on top of an overall increase of one to two feet predicted by 2100 as a result of global warming. That prediction, by the Intergovernmental Panel on Climate Change, a United Nations body, was rendered in a 2007 report that more or less ignored the question of melting glaciers and ice sheets because the process is so hard to forecast. As a result, many researchers regard the prediction as unrealistically optimistic.

(Via NYT)