On March 7th, the Arctic sea ice most likely reached its maximum extent for the year -- signaling the beginning of the melt season -- and that maximum tied for the lowest ever seen on the satellite record. The maximum extent was 5.65 million square miles, which may sound like a lot, until you consider that's 463,000 square miles less than the average recorded between 1979 and 2000. That's a little more than 8% less than the average -- and it gives us some more good evidence that warming is continuing to cause the Arctic to melt at a rather profound rate. Here's the most recent report from the National Snow Ice and Data Center (NSIDC):
On March 7, 2011, Arctic sea ice likely reached its maximum extent for the year, at 14.64 million square kilometers (5.65 million square miles). The maximum extent was 1.2 million square kilometers (471,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles), and equal (within 0.1%) to 2006 for the lowest maximum extent in the satellite recordYou can see for yourself the difference between this year's maximum extent and the average extent from 1979-2000 (the orange line indicates ice extent in years past):
Both images via NSIDC
And here's the data charted out:
It's impossible to look at this data and even try to argue, with a straight face, that we're not seeing a major warming trend -- or more absurdly, though I still hear it sometimes, that we're entering a 'cooling period'. The Arctic is melting, not-so-slowly but surely, boys and girls.