Arctic continues to warm at rapid rate

Arctic air temperatures continue to warm at more than twice the rate of global air temperatures, which could result in broad impacts on trade and climate, federal scientists announced Wednesday.

"We are an Arctic nation. ... What happens up there in the Arctic matters to us down here," said Martin Jeffries, a scientist with the Office of Naval Research and the lead editor of the annual "Arctic Report Card." The report was issued Wednesday by scientists with the National Oceanic and Atmospheric Administration.

The warmth in the Arctic was caused partly by the Arctic amplification of global warming, which results from the loss of summer sea ice.

"When bright and reflective ice melts, it gives way to a darker ocean; this amplifies the warming trend because the ocean surface absorbs more heat from the sun than the surface of snow and ice, " according to NASA.

The sea ice in question is frozen ocean water that melts each summer, then refreezes each winter. The Arctic's drop in reflectivity is crucial because "it plays a role like a thermostat in regulating global climate," Jeffries said.

In as few as five to 10 years or as many as several decades, summer sea ice could disappear entirely across the Arctic, Jeffries said. There's no way to pinpoint a more exact time frame, he added.

The rising warm temperatures and reduction in sea ice will create additional opportunities for activities such as shipping, fishing and resource extraction from countries around the Arctic, said Craig McLean, acting assistant administrator for the NOAA Office of Oceanic and Atmospheric Research.

Other items from the report, which covers the months from October 2013 to September 2014:

• Melting occurred across almost 40% of the surface of the Greenland ice sheet, a rate that is above average.

• Record warm temperatures were recorded in Alaska in January.

• Spring snow cover in Eurasia reached a record low in April.

• June snow cover in North America was the third-lowest on record.

• Arctic summer sea ice in 2014, while not setting a new record low, continued its long-term, steady decline.

At the same time, while the population of polar bears shrunk in parts of Alaska, they were more or less stable elsewhere, the report said. Polar bears are largely dependent on sea ice to travel, hunt and mate, making their population size an indicator of how climate change is affecting wildlife in the region.

The number of polar bears in the entire Arctic is not known because the area is so large and it's difficult to count and track the animals, said Geoff York, senior director of conservation with Polar Bears International.

Contributing: The Associated Press