Arctic ice melting rapidly, study says

By SETH BORENSTEIN, AP Science WriterThu Sep 14, 5:41 AM ET

Arctic sea ice in winter is melting far faster than before, two new NASA studies reported Wednesday, 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 Arcticsea ice in the summer, but they had not seen a big winter drop in sea ice, even though they expected it.