I had a Skype chat Wednesday about Siberian permafrost in the context of climate change with Marina Leibman, a top Russian permafrost expert who had just returned from examining the unusual crater spotted on the Yamal Peninsula in Siberia late last week.

We talked just before fresh reports circulated about reindeer herders finding another such hole in the region.....

Leibman, the chief scientist at the Earth Cryosphere Institute of the Siberian Branch of the Russian Academy of Sciences, has studied permafrost since 1973 and has a remarkable publication record.

She describes how the first hole (and presumably the new one) appear to have formed as methane is released from a warming mix of ice, water and soil, building up pressure that explosively pushed out the top of the hole, heaving chunks of earth many yards in some directions.....

She said there were no signs of combustion, that the hole had to be at least a year old because there was fresh greenery from this summer season with no overlying layer of mud or the like.

Leibman stressed that there were no indications that such events were more than the normal process of lake formation in the area and predicted that the hole she inspected would end up being a lake in coming years.

She also stressed that she sees no signs of current or imminent warming producing a great destabilization of permafrost in the Arctic: “You can’t say in 20 years it will be 2 degrees warmer so permafrost will be thawing. It will make it 2 degrees warmer, but not thawing – at least in the far north.....