Apocalypse Soon?

Dahr Jamail follows up on previous reports to describe a study published in Palaeoworld called
"Methane Hydrate: Killer cause of Earth's greatest mass extinction".  From the abstract:

Global warming triggered by the massive release of carbon dioxide may be catastrophic, but the release of methane from hydrate may be apocalyptic.

Oh, and for the third straight year, Arctic sea ice is at a record-low maximum.

Update (January 14, 2018):  An Arctic News report says methane levels as high as 2764 ppb were recorded this month. A Science News story indicates that at least some of the methane hydrate breakdown is attributed to post-glacial uplift.

Update (January 19, 2020):  Robert Hunziker explains how the East Siberian Arctic Shelf may become a troublesome source of methane.