March 24, 2006 in Nation/World

Studies show ice caps are melting faster

Dennis O'brien Baltimore Sun
 
Associated Press photo

A section of the ice sheet covering much of Greenland is seen last August. Scientists say the ice is thinning and blame global warming.
(Full-size photo)

Polar ice sheets are melting faster than authorities realize and could eventually submerge coastal communities worldwide, according to two studies released today.

Researchers from the University of Arizona and the National Center for Atmospheric Researchers noted that sea levels rose 20 feet during a warming period about 130,000 years ago – and said the waters could rise just as high sometime after 2100 if global temperatures continue to climb.

Scientists have been warning for decades that carbon dioxide and other so-called greenhouse gases from power plants and car exhaust are warming the planet and raising the seas. They say the best way to minimize the damage is to drastically reduce smokestack and tailpipe emissions.

The two studies published today in the journal Science argue that the impact of melting from Antarctica’s ice sheets has been underestimated.

That melting will exacerbate the effects of global warming and play a major role in submerging many coastal communities if nothing is done to curb the emissions, the researchers say.

No one is sure of the extent of the melting or the timing of its effects. But the researchers say that with the warming climate, melting ice sheets in Greenland, the Arctic and Antarctica could inundate coastal areas around the world.

Maps released with the studies show extensive coastal areas in Florida, New Orleans and Cape Cod, Mass., that the researchers say might one day be submerged.

“As (Hurricane) Katrina pointed out, we only need a meter of sea level rise to make much of New Orleans unlivable. The same goes for a number of coastal areas,” said Jonathan T. Overpeck, a geosciences professor at the University of Arizona and lead author of one study.

In Maryland, rising sea levels are washing away islands in the Chesapeake Bay and threatening hundreds of homes, roads and businesses, said J. Court Stevenson, a professor at the University of Maryland Center for Environmental Sciences at Horn Point who has been studying the regional effects of rising sea levels since the 1980s.

Earth’s average temperature has increased about 1 degree Fahrenheit over the past 30 years, a relatively rapid rise, scientists say, and sea levels are rising about 1 inch each decade.

The seas have risen and fallen significantly since Earth was formed more than 4 billion years ago. Sea levels rise and fall based on long-term climate patterns and the amount of ice in polar ice sheets, experts say.

But by focusing on a particularly warm stretch about 130,000 years ago, researchers say they found how much sea levels will rise as temperatures continue to climb.

“We estimate the high end is 3 feet per century, but it could be faster,” Overpeck said.


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