Arctic sea ice in winter is melting far faster than before -- a new and alarming trend that threatens the ocean's delicate ecosystem. The sudden and rapid melting is a sure sign of man-made global warming, said researchers in NASA studies Wednesday. "It has never occurred before," said NASA senior research scientist Josefino Comiso. "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 have 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 has declined by another 1.9 percent, according to Comiso. - RSOE HavariaThat ain't good.