Arctic Just Witnessed Fastest August Ice Retreat in History
Images from NSIDC
While we may have narrowly avoided setting a new record high in Arctic ice loss this year, it look as though we may have still hit a dubious milestone: achieving the fastest rate of melting during a four-week period in August than at any time in recent history. Between August 1 and August 31, sea ice declined at a rate of 32,700 square miles per day compared to a rate of roughly 24,400 square miles per day last year. The historical average for that period is 19,700 square miles per day.
As Matthew noted in a recent post, we barely missed passing the record set last year. According to the U.S. National Snow and Ice Data Center (NSIDC), sea ice covered around 4.5 million square kilometers at its lowest point on September 12; by comparison, sea ice covered 4.1 million square kilometers the same time last year.
Not that we should consider this temporary reprieve an auspicious sign. The BBC article Matthew cited quoted the NSIDC's Walt Meier as saying: "(...) so people might be tempted to call it a recovery, but I don't think that's a good term, we're still on a downwards trend towards ice-free Arctic summers." Indeed, most climate scientists still believe that, if present trends continue, all arctic sea ice will be gone by the end of the century.
Researchers believe that the uptick in melting could be due in part to conditioning taking place in the region; in a study published in Geophysical Research Letters, Jennifer Kay of the National Center for Atmospheric Research (NCAR) and her colleagues found that diminished cloud cover in 2007 allowed more sunlight to reach Earth, which caused more ice melting at the surface and, by warming sea surface temperatures, melting from below as well. This trend is likely to continue as the sea ice, besieged by warming surface water temperatures on one side and a higher albedo effect on the other, becomes thinner and loses the capacity to regenerate.
More about Arctic ice cap melting
::Arctic Ice Is Melting At Record Highs
::Melting Arctic Ice Increases Permafrost Thaw Farther Inland Than Previously Thought
::Oh! So Close: Arctic Sea Ice Summer Melt Fails to Set Record in 2008