NASA spots 'unstoppable' Antarctic ice sheet melt

NASA spots 'unstoppable' Antarctic ice sheet melt

 

Two new studies indicate that part of the huge West Antarctic ice sheet is starting a slow collapse in an unstoppable way. Alarmed scientists say that means even more sea level rise than they figured.

 

By The Associated Press

 

WASHINGTON —

The huge West Antarctic ice sheet is starting a glacially slow collapse in an unstoppable way, two new studies show. Alarmed scientists say that means even more sea level rise than they figured.

 

The worrisome outcomes won't be seen soon. Scientists are talking hundreds of years, but over that time the melt that has started could eventually add 4 to 12 feet to current sea levels.

 

A NASA study looking at 40 years of ground, airplane and satellite data of what researchers call "the weak underbelly of West Antarctica" shows the melt is happening faster than scientists had predicted, crossing a critical threshold that has begun a domino-like process.

 

"It does seem to be happening quickly," said University of Washington glaciologist Ian Joughin, lead author of one study. "We really are witnessing the beginning stages."

 

It's likely because of man-made global warming and the ozone hole which have changed the Antarctic winds and warmed the water that eats away at the feet of the ice, researchers said at a NASA news conference Monday.

 

"The system is in sort of a chain reaction that is unstoppable," said NASA glaciologist Eric Rignot, chief author of the NASA study in the journal Geophysical Research Letters. "Every process in this reaction is feeding the next one."