Arctic ice melted to record low this summer
It's official: The annual summer melting of sea ice at the top of the world hit a record low this year, with ice only covering an area some 39 percent smaller than the long-term median from 1979-2000. To put it in perspective, that means we lost the equivalent of six Californias in sea ice this year beyond that median ice extent.
The National Snow and Ice Data Center (NSIDC) issued a press release about it Oct. 1, noting that if ship and aircraft observation data from before the satellite era are taken into account, the sea ice might have dwindled by 50 percent since the 1950s. As a result of all of this melting, the fabled Northwest Passage opened for the first time in human memory.
The New York Times had an excellent article today describing the melt and what scientists attribute it to. It turns out there are many causes, including clouds and water vapor, warm winds, unusually sunny days in June and July, the movement of older, thicker sea ice to the North Atlantic, and climate change.
Times writer Andrew Revkin notes that "Some scientists who have long doubted that a human influence could be clearly discerned in the Arctic's changing climate now agree that the trend is hard to ascribe to anything else."
NSIDC Senior Scientist Mark Serreze adds (in the press release), "While a number of natural factors have certainly contributed to the overall decline in sea ice, the effects of greenhouse warming are now coming through loud and clear."
The sea ice could totally melt during summer by the year 2030. The danger of massive sea ice melt is that open ocean water absorbs heat. Normally the white sea ice reflects a lot of solar energy back into space. Losing that control on solar energy could hit the climate hard, warming up the ocean and causing sea levels to rise – because warm water expands and takes up more space. As the Arctic Ocean warms and the melting season lasts longer, it becomes more difficult for the sea ice to refreeze. It's a nasty feedback loop.
The later freeze and earlier ice breakup is affecting people who live in the Arctic in terms of when they can hunt and travel. The melting also affects polar bears, which normally hunt seals from the sea ice. One scientist says two-thirds of all polar bears could die by mid-century.
View our Greenland photo gallery to see how ice melt is affecting people there.
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