August 13, 2008

West Antarctica Rapidly Melting Away

Four years of scientific research on ice core data has brought to light the warming trend in West Antarctica, the world's coldest climate. 

According to the study, the West Antarctic warmed in response to higher temperatures in the tropical Pacific, which itself has been warming due to weather patterns including an El Nino event from 1939 to 1942 and greenhouse emissions from cars and factories.

"An increasingly large part of the signal is becoming due to human activity," said the study's lead author David Schneider of the National Center for Atmospheric Research.

The study appeared on Tuesday in the journal Proceedings of the National Academy of Sciences.

Previous researchers had found the West Antarctic cooled partly due to winds caused by depletion of the ozone layer.

Air pressure accompanied by oceanic warming in the tropical Pacific is responsible for producing El Nino.

Scientists are investigating if warming will destabilize the West Antarctic ice sheet.

It covers a region the size of Mexico and averages about 6,500 feet deep. If it all melted, it would raise sea levels by 8 to 16 feet.

The study, supported by the National Science Foundation, showed the West Antarctic warned about 1.6 degrees Fahrenheit (0.9 C) over the 20th century.

That's slightly higher than the global average of about 1.3 degrees F (0.7 C), though there was some uncertainty in the estimate.

The U.N. Intergovernmental Panel on Climate Change said in 2007, the Antarctica would not contribute to rising sea levels. The panel instead predicted a growth of the big ice sheet the covers much of the continent from enhanced precipitation.

Schneider said there are parts of Antarctica that are gaining snowfall and ice, but the overall trend for the continent is that the ice is disappearing.


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