A new article in Nature warns that “the costs of a melting Arctic will be huge”, thanks in part to the likely release of “a 50-gigatonne (Gt) reservoir of methane, stored in the form of hydrates” beneath the East Siberian Arctic Shelf, “either steadily over 50 years or suddenly”. An abrupt release is “highly possible at any time”, says Natalia Shakhova of the University of Alaska at Fairbanks, who has observed plumes of methane up to a kilometre wide bubbling to the surface in the area.
We calculate that the costs of a melting Arctic will be huge, because the region is pivotal to the functioning of Earth systems such as oceans and the climate. The release of methane from thawing permafrost beneath the East Siberian Sea, off northern Russia, alone comes with an average global price tag of $60 trillion in the absence of mitigating action — a figure comparable to the size of the world economy in 2012 (about $70 trillion). The total cost of Arctic change will be much higher. (Gail Whiteman, Chris Hope and Peter Wadhams, “Vast costs of Arctic change”, Nature 499, 25 July 2013, p. 401)
A 50-gigatonne (Gt) reservoir of methane, stored in the form of hydrates, exists on the East Siberian Arctic Shelf. It is likely to be emitted as the seabed warms, either steadily over 50 years or suddenly. Higher methane concentrations in the atmosphere will accelerate global warming and hasten local changes in the Arctic, speeding up sea-ice retreat, reducing the reflection of solar energy and accelerating the melting of the Greenland ice sheet. (p. 402)
The methane pulse will bring forward by 15–35 years the average date at which the global mean temperature rise exceeds 2°C above pre-industrial levels — to 2035 for the business-as-usual scenario and to 2040 for the low-emissions case. (p. 402)
Methane hydrates (or clathrates) and Shakhova previously on Mefi.
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