Despite a cool, cloudy summer, the ice levels in the Arctic have shrunk enough to tie with the second-lowest Arctic sea ice minimum, recorded in 2007. "Historically such weather conditions slow down the summer ice loss, but we still got down to essentially a tie for second lowest on the satellite record," reports US National Snow and Ice Data Center (NSIDC) director Mark Serreze.

In a joint report released by the NSIDC and NASA, the agencies reported that ice levels hit their nadir this year on September 10, with only 4.4 million square kilometers (1.6 million square miles) covering the Arctic. The lowest recorded levels were observed in September of 2012, at 3.39 million square km. It is estimated that if this season hadn’t been as cool as it was, ice loss would have exceeded 2012’s record low. As it was, the ice melt accelerated faster than normal over the first ten days of September this year, melting 62 percent faster than the 1981-2010 average rate.

As an example of how much ice has melted thus far, the Swedish icebreaker Oden has been able to navigate open water to within three-quarters of a nautical mile of the geographic North Pole itself, according to a photograph of the vessel posted in a Tweet by the Canadian Coast Guard.

Earth’s polar ice is important in that it helps reflect solar radiation back into space, helping to keep temperatures stable. However, as the ice melts, it exposes open water that absorbs solar radiation much easier than the ice would have, contributing to the planet’s absorption of yet even more heat.