North Pole Meets South Pole: Earth  Is Melting at Both Ends
Melting Ice Caps Could Spell  Disaster for Coastal Cities
By BILL BLAKEMORE


(March 2) - For the first time, scientists have  confirmed Earth is melting 
at both ends, which could have disastrous effects for  coastal cities and 
villages.

Antarctica has been called "a slumbering giant" by a  climate scientist who 
predicts that if all the ice melted, sea levels would rise  by 200 feet. Other 
scientists believe that such a thing won't happen, but new  studies show that 
the slumbering giant has started to stir.

Melting at Both Ends

Recent studies have confirmed that the North Pole and  the South Pole have 
started melting.

Experts have long predicted that global warming would  start to melt 
Greenland's two-mile-thick ice sheet, but they also thought the  more massive ice 
sheet covering Antarctica would increase in the 21st  century.

It seems they were wrong.

Two new studies find that despite the increasing  snowfall that comes with 
global warming as a result of the increased moisture in  the air, Antarctica's 
ice sheets are losing far more than the snow is  adding.

According to the National Academy of Sciences, Earth's  surface temperature 
has risen by about 1 degree Fahrenheit in the last century,  with accelerated 
warming during the last two decades. Most of the warming over  the last 50 
years is attributable to human activities through the buildup of  greenhouse gases 
— primarily carbon dioxide, methane and nitrous oxide. Although  the 
heat-trapping property of these gases is undisputed, uncertainties exist  about 
exactly how Earth's climate responds to them.
 
 
 
 (http://reference.aol.com/nowyouknow/globalwarming/photos)  
The melting rate of Greenland glaciers has doubled since 1996. See  images of 
global warming effects. 
 






"The warming ocean comes underneath the ice shelves and  melts them from the 
bottom, and warmer air from the top melts them from the  top," said NASA 
glaciologist Jay Zwally. "So they're thinning and eventually  they get to a point 
where they go poof!"

Zwally explains that the ice shelves, which the  Antarctic ice cap pushes out 
into the ocean, are responding more than they  expected to Earth's warming 
air and water. If the melting speeds up to a rapid  runaway process called a 
"collapse," coastal cities and villages could be in  danger.

James Hansen, director of NASA's Earth Science  Research, said that disaster 
could probably be avoided, but that it would  require dramatically cutting 
emission outputs. If the proper actions aren't  taken, Hansen said, the sea level 
could rise as much as 80 feet by the time  today's children reach middle age.

"We now must choose between a serious problem that we  can probably handle 
and, if we don't act soon, unmitigated disaster down the  road," Hansen said.
 



Scientists looking at ice cores can now read Earth's  temperatures from past 
millennia and match them to sea levels from those  eras.

"Based on the history of the Earth, if we can keep the  warming less than 2 
degrees Fahrenheit, I think we can avoid disastrous ice  sheet collapse," 
Hansen said.

Hansen and other scientists point out that a rise of at  least 1 degree 
Fahrenheit — and another few feet of sea level — seem virtually  certain to happen 
because of the carbon that mankind has already put in the  atmosphere.

Copyright 2006 ABCNEWS.com


2006-03-02  12:18:22