So are you claiming that you know of some proxy data that indicates that local temperatures specifically over major permafrost areas were higher some time in the past than they are today? (realclimate.org)
Larry Hinzman, a permafrost hydrologist at the University of Alaska in Fairbanks and director of the International Arctic Research Center, says that such craters could become more common in permafrost areas as the region heats up. (nature.com)
Experiments with warmed permafrost areas have so far been lacking, but now the true situation can be calculated. (earthtimes.org)