Climate Central: If youd asked permafrost researcher Vladimir Romanovsky five years ago if he thought the permafrost of the North Slope of Alaska was in danger of substantial thaw this century because of global warming, he would have said no. The permanently frozen soils of the northern reaches of the state are much colder, and so more stable than the warmer, more vulnerable permafrost of interior Alaska, he would have said. I cannot say it anymore he told journalists last month at the annual meeting of the American...