New satellite observations show that sea ice in the Arctic is melting faster while air temperatures in the region are rising sharply.
Since 2002, satellite data have revealed unusually early springtime melting in areas north of Siberia and Alaska. Now the melting trend has spread throughout the Arctic, according to a national collaboration of scientists.
The latest observations through September show that melting in 2005 began a record 17 days earlier than usual.
The observations showed 2.06 million square miles of sea ice as late as Sept. 19. That's the lowest measurement of Arctic sea ice cover ever recorded, the researchers said. It's also 20 percent less than the average of end-of-summer ice pack cover measurements recorded since 1978.
At the same time, average air temperatures across most of the Arctic region from January to August 2005 were as much as 5.4 degrees warmer than average temperature over the last 50 years, said the team of researchers from two universities and NASA.
The scientists stopped short of directly blaming the melting trend on global warming but said they have few other explanations at this point.
"Something has fundamentally changed here, and the best answer is warming," the AP quoted Mark Serreze, another researcher at the snow and ice data center.