The state of global polar sea ice at the beginning of October 2010 was once again very poor compared to climatological conditions (1979-2008). The Arctic ice extent was far, far below average for this time of year. The Antarctic sea ice extent wass above average, but not nearly so much as was the case in the Arctic. Unfortunately, global sea ice extent fell to ~17.5 million sq. km., something that has happened in only 2 previous Septembers: in 2007 and 2008. The Northwest Passage and the Northern Sea Route are largely free of ice, allowing the Arctic Ocean to potentially be circumnavigated.
This post will mostly concentrate on the extremely poor conditions found in the Arctic this fall. Antarctic conditions are not as extreme, largely and ironically thanks to the ozone hole over the continent which has kept stratospheric temperatures much cooler than they otherwise would be. Eventually, our forcing leading to global warming will overwhelm the ozone hole cooling effect (and the ozone hole will gradually be “healed” anyway), which will cause long-term changes to Antarctica just like the Arctic.