Unusual Ice Melting Man-made or Natural Cycle?
These two images show Arctic sea ice extent from January 1, 1990 (left), and January 1, 1999, (Right) respectively. These images were created using data from the Defense Meteorological Satellite Program's (DMSP) Special Scanning Microwave Imager (SSM/I). Credit: NASA
For more info read the report from 2003
The Arctic Perennial Sea Ice Could Be Gone by End of the Century
September 14, 2006
Fast-melting Arctic ice alarms NASA scientists
THE ASSOCIATED PRESS
appeared in the Cape Cod Times
Arctic sea ice in winter is melting far faster than before, two new NASA studies reported yesterday, a new and alarming trend that researchers say threatens the ocean's delicate ecosystem.
Scientists point to the sudden and rapid melting as a sure sign of man-made global warming.
''It has never occurred before in the past,'' said NASA senior research scientist Josefino Comiso in a phone interview. ''It is alarming. ... This winter ice provides the kind of evidence that it is indeed associated with the greenhouse effect.''
Scientists have long worried about melting Arctic sea ice in the summer, but they had not seen a big winter drop in sea ice, even though they expected it.
For more than 25 years Arctic sea ice has slowly diminished in winter by about 1.5 percent per decade. But in the past two years, the melting has occurred at rates 10 to 15 times faster. From 2004 to 2005, the amount of ice dropped 2.3 percent; and over the past year, it's declined by another 1.9 percent, according to Comiso.
A second NASA study by other researchers found the winter sea ice melt in one region of the eastern Arctic has shrunk about 40 percent in just the past two years.
This is partly because of local weather but also partly because of global warming, Comiso said.
The loss of winter ice is bad news for the ocean because this type of ice, when it melts in summer, provides a crucial breeding ground for plankton, Comiso said. Plankton are the bottom rung of the ocean's food chain.
''If the winter ice melt continues, the effect would be very profound especially for marine mammals,'' Comiso said.
The ice is melting even in subfreezing winter temperatures because the water is warmer and summer ice covers less area and is shorter-lived, Comiso said.
(Published: September 14, 2006)