The methane eruptions creating great craters in Siberia are a natural response to warming permafrost. Alaska’s permafrost (and probably Canada’s too) is subjected to the same conditions. There are already precursors that are being watched as scientists attempt to better understand and predict the phenomenon.
“Siberia’s Permafrost Is Exploding. Is Alaska’s Next?” – Slate
Pretending Not To Panic 
Pingback: Numbers For Thawing Permafrost | Pretending Not To Panic