Sea-level rise may pose greatest threat to Northeast US and Canada this century

Washington, May 28 (ANI): A new research has suggested that the melting of the Greenland Ice Sheet this century may drive more water than previously thought toward the already threatened coastlines of New York, Boston, Halifax and other cities in the northeastern United States and Canada.

The researchers suggest that moderate to high rates of ice melt from Greenland may shift ocean circulation by about 2100, causing sea levels off the northeast coast of North America to rise by about 30 to 51 centimeters (12 to 20 inches) more than other coastal areas.

The research builds on recent reports that have found that sea level rise could adversely affect North America, and its findings suggest that the situation is even more urgent than previously believed.

"If the Greenland melt continues to accelerate, we could see significant impacts this century on the northeast U.S. coast from the resulting sea level rise," said scientist Aixue Hu, the research paper's lead author.

"Major northeastern cities are directly in the path of the greatest rise," Hu added.

To assess the impact of Greenland ice melt on ocean circulation, Hu and his coauthors used the Community Climate System Model, an NCAR-based computer model that simulates global climate.

They considered three scenarios: the melt rate continuing to increase by 7 percent a year, as has been the case in recent years, or the melt rate slowing down to an increase of either 1 or 3 percent a year.

If Greenland's melt rate slows down to a 3 percent annual increase, the study team's computer simulations indicate that the runoff from its ice sheet could alter ocean circulation in a way that would direct about a foot of water toward the northeast coast of North America by 2100.

This would be on top of the average global sea level rise expected as a result of global warming.

Although the study team did not try to estimate that mean global sea level rise, their simulations indicated that melt from Greenland alone under the 3 percent scenario could raise sea levels by an average of 53 centimeters (21 inches).

But if the melt rate continued at its present 7 percent increase per year through 2050 and then leveled off, the study suggests that the northeast coast could see as much as 51 centimeters (20 inches) of sea level rise above a global average that could be several feet.

According to NCAR scientist Gerald Meehl, "Ocean dynamics will push water in certain directions, so some locations will experience sea level rise that is larger than the global average." (ANI)