“A new daily record … would be likely by the end of August,” said Ted Scambos, lead scientist at the data center, which monitors ice in the Arctic and elsewhere. “Chances are it will cross the previous record while we’re still in sea ice retreat.”
The amount of sea ice in the Arctic is important because this region is a potent global weather-maker, sometimes characterized as the world’s air conditioner. This year, the loss of sea ice in the Arctic has suggested a possible opening of the Northwest Passage north of Canada and Alaska and the Northern Sea Route by Europe and Siberia.
As parts of the Arctic melted, 2012 also set records for heat and drought in much of the Northern Hemisphere temperate zone, especially the continental United States.
This summer could see the ice retreat to less than 1.5 million square miles (4 million square km), an unprecedented low, Scambos said.
The previous record was set in 2007, when Arctic ice cover shrank to 1.66 million square miles (4.28 million square km), 23 percent below the earlier record set in 2005 and 39 percent below the long-term average from 1979 to 2000. …
If the sea ice record is broken this month, that would be unusually early in the season; last year’s low point came on September 9, 2011.
Typically, the melting of Arctic sea ice slows down in August as the Northern Hemisphere moves toward fall, but this year, it has speeded up, Scambos said. “I doubt there’s been another year that had as rapid an early August retreat,” he said.
Overall, the decline of Arctic sea ice has happened faster than projected by the United Nations Intergovernmental Panel on Climate Change five years ago, according to NSIDC data ( here ).
To Scambos, these are clear signs of climate change spurred by human activities, notably the emission of heat-trapping greenhouse gases including carbon dioxide.
“Everything about this points in the same direction: we’ve made the Earth warmer,” he said. …