In just the last six days, researchers say 69,000 square miles of Arctic ice has disappeared, roughly the size of the Sunshine State.Scientists say the rate of melting in 2007 has been unprecedented, and veteran ice researchers worry the Arctic is on track to be completely ice-free much earlier than previous research and climate models have suggested.
"If you had asked me a few years ago about how fast the Arctic would be ice free in summer, I would have said somewhere between about 2070 and the turn of the century," said scientist Mark Serreze, polar ice expert at the NSIDC. "My view has changed. I think that an ice-free Arctic as early as 2030 is not unreasonable."
Sea ice melt will likely reach the absolute minimum in the next few days as temperatures at the North Pole cool and refreezing begins.
Melting sea ice, unlike land-based glaciers like the ones in Greenland and elsewhere, does not raise sea level. But it does play a major role in regulating the planet's climate by affecting air and ocean currents.
"It will shift some of the weather patterns in ways that we are just beginning to understand," said Robert Correll, a scientist who chairs the Arctic Climate Impact Assessment and is also the climate change director at the Heinz Center for Science, Economics and the Environment in Washington, D.C.
Correll said that white sea ice also acts as a mirror at the top of the planet, reflecting much of the sun's energy back into space. As it melts, it reveals darker water that absorbs more energy from the sun -- further warming the ocean in a process scientists call a "feedback."
"If there is no ice, the ocean is going to continue to heat, and that is going to accelerate the global warming process," said Correll. (More)
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