Arctic meltdown modeled

Press coverage is rising of a large study that models the climate of the Arctic region over the coming century. As usual, most stories give almost no supporting information--that's because the study won't be released until next week--but trumpet the worst case, in which the Arctic will be ice-free in summer by 2070. New Scientist's article does note that the worst case is from a single climate model out of five used by the authors, and that it's based on a CO2 scenario "where global warming gas emissions are double their pre-industrial level." That statement isn't quite clear. But you can delve into the detail yourself starting November 9, when material will be released on the Arctic Climate Impact Assessment site. American media will see the report the day before.