>Their paper initially included the line that the "release of up to 50 gigatonnes of predicted amount of hydrate storage [is] highly possible for abrupt release at any time". A release on this scale would increase the methane content of the planet's atmosphere by a factor of twelve,[62][63] equivalent in greenhouse effect to a doubling in the 2008 level of CO2.

https://en.wikipedia.org/wiki/Arctic_methane_emissions