Scientists from the University of Stockholm have detected gigantic methane plumes escaping from the sea floor of the Laptev continental slope. It is believed that this is due to the melting of methane hydrates that have been frozen on the floor of the ocean. They are now melting and releasing the gas because the Arctic Ocean, along with the rest of the arctic, is warming rapidly.
In the past, interglacials such as the one we are in now have ended with a sudden release of methane from Arctic Ocean hydrates, which has been followed by a period of extreme global heating that, when the methane dissipates, transforms violently into a much colder regime that brings on another ice age. Whitley Strieber and Art Bell detailed this process in Superstorm, which was generally dismissed as nonsense.
Methane is a potent greenhouse gas. It retains 50 times more heat in the atmosphere than carbon dioxide, and will cause global heating that will make the planet non-viable for humans in some areas, most notably the world's deserts, the US Southwest, southern China and southern India. Once all the methane hydrates are melted and methane stops releasing, it will dissipate, and the heat trapped in the atmosphere will be released into space. As human activity by that time will no longer be extensive enough to contribute any significant warming effect, the Holocene interglacial will end and the planet will return to a much colder regime than we now enjoy.
If the methane releases slowly, it will dissipate faster than it accumulates in the atmosphere, and the process won't generate a dramatic climate shift. This hopeful outcome seems unlikely, however, because the methane plumes already appearing are 'vast' according to the SWERUS-C3 scientists who made the observations. It is believed that an incursion of warmer Atlantic water that stretches deep into the Arctic Ocean has become warmer, causing the hydrates to release.