Center for a New American Security

The average Arctic sea ice extent for July 2010 was the second lowest on record (the record low was in July 2007).  The total ice extent was 8.4 million square kilometers, which was 1.71 million square kilometers less than the 1979-2000 average (shown in the above image by the magenta line).  According to the National Snow and Ice Data Center, the ice retreat for this July is part of a trend that shows a linear rate of decline of 6.4 percent.  Translation? It’s official: Arctic ice data is suggesting a retreating trend, not just a random pattern of expansion and decline.  Worse (at least for the polar bears), this means that the oldest, thickest ice is now being lost, not just the ice that accumulates between summer melting.

Photo: Courtesy of the National Snow and Ice Data Center in Boulder, CO.