[cripplecreek]

"Global warming, causing an alarming melt in the ice under the soil, released gas causing an effect like the popping of a Champagne cork," the news report said, citing an expert at the Subarctic Scientific Research Center.

In other words they aren't really sure so they used the catch all phrase.

[IMR 4350]

Probably methane hydrate same as found on the bottom of the ocean.

Reaches a saturation point then pop!

[gleeaikin]

What worries scientists is that when the permafrost melts, vast amounts of CO2 are released, and if CO2 causes global warming then you have a self perpetuating temperature rise phenomenon. I hope they are wrong.