National Geographic News
Arctic warming has become so dramatic that the North Pole may melt this summer, report scientists studying the effects of climate change in the field.
"We're actually projecting this year that the North Pole may be free of ice for the first time [in history]," David Barber, of the University of Manitoba, told National Geographic News aboard the C.C.G.S. Amundsen, a Canadian research icebreaker.
Firsthand observations and satellite images show that the immediate area around the geographic North Pole is now mostly annual, or first-year, ice—thin new ice that forms each year during the winter freeze.
Such ice is much more prone to melting during the summer months than perennial, or multiyear, ice, which is thick and dense ice that has lasted through multiple cycles of thawing and refreezing.
"I would say the ice in the vicinity of the North Pole is primed for melting, and an ice-free North Pole is a good possibility," Sheldon Drobot, a climatologist at the Colorado Center for Astrodynamics Research at the University of Colorado, said by email.
The melt would be mostly symbolic—thicker ice, pushed against the Canadian continental shelf by weather and Earth's rotation, would still survive the summer.
Recent models suggest that the Arctic won't see its first completely ice-free summer until somewhere between 2013 and 2030.
But this summer's forecast—and unusual early melting events all around the Arctic—serve as a dire warning of how quickly the polar regions are being affected by climate change.
Scientists are particularly interested in the North and South Poles because they are expected to show the most dramatic effects of global warming.
Models predict that the regions will see temperature increases roughly three times as quickly as the rest of the globe because of an effect known as ice albedo feedback, which occurs when highly reflective ice gives way to dark water.
The water absorbs much more of the sun's energy, increasing temperatures and causing further ice melting.
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