Read here, here and here. Arctic sea ice is affected by a number of powerful forces other than air temperatures. Although polar sea ice could have disappeared for short spans during the very warm summers in the past, the present Arctic sea ice condition remains quite large, even at its minimum during the summer months. For a historical perspective of the melting Arctic sea ice saga, this is an excellent piece. And despite the climate "expert predictions" that the South Pole sea ice would also soon disappear, since 1979 nothing could be further from the truth as 2009 was a record sea ice extent year. (click on image to enlarge)