Arctic sea ice extent for August 26, 2012 (right) was 4.10 million square kilometers, which was 70,000 square kilometers below the September 18, 2007 daily extent of 4.17 million square kilometers. Illustration: National Snow and Ice Data Center
Three weeks before the likely minimum, the melting of Arctic sea ice has already broken the record set in 2007. The daily rate of loss is now 50 percent higher than it was that year.
An area the size of Finnmark and Troms counties disappears every day.
According to a report released on Monday by the U.S. National Snow and Ice Data Center, Arctic sea ice area has shrunk to 4.10 million square kilometers, breaking the previous minimum of 4.17 million square kilometers. With weeks still to go in the summer melting season, it is clear that the record will be beaten by a wide margin.
After tracking near 2007 levels through July, the extent declined rapidly in early August. Since then, the loss rate has slowed some, averaging about 75,000 square kilometers per day - equivalent to the size of Norway’stwo northernmost counties of Troms and Finnmark together.
The amount of sea ice in the summer season has declined more than 40 percent since satellite tracking began in the late 1970s.
The fast melt of the Arctic ice is self-reinforcing. Since sea ice is white, it reflects 80 percent of the sunlight hitting it back into space; the less of it is the more heat the darker Arctic will absorb. Instead of reflecting 80 percent, it will absorb 90 percent of the sunlight, which will accelerate the thaw, scientists say.
Scientific forecasts based on computer modeling have long suggested that the Arctic could be completely free of ice in the summer by the middle of the century. This year’s prodigious melting is lending credibility to more pessimistic analyses that that moment may come much sooner, perhaps by the end of this decade.