Arctic sea ice may disappear by 2013: Arctic sea ice is in trouble and the implications of the global feedback caused by the lack of sea ice are extreme. Open water absorbs eight times more heat than does ice. Ice reflects the heat harmlessly back to space. Water keeps the heat to melt more ice and to add heat to the atmosphere that then stays in the atmosphere because of the greenhouse effect. Polar ice is the Earth’s air conditioner. The warming feedback caused by melting polar ice, because of this unprecedented ice melt in the Arctic, is not represented in the global climate models. This is happening 70 years ahead of schedule (see here).