An anonymous reader quotes a report from The Guardian: Scientists have found evidence that frozen methane deposits in the Arctic Ocean -- known as the "sleeping giants of the carbon cycle" -- have started to be released over a large area of the continental slope off the East Siberian coast, the Guardian can reveal. High levels of the potent greenhouse gas have been detected down to a depth of 350 meters in the Laptev Sea near Russia, prompting concern among researchers that a new climate feedback loop may have been triggered that could accelerate the pace of global heating. The slope sediments in the Arctic contain a huge quantity of frozen methane and other gases -- known as hydrates. Methane has a warming effect 80 times stronger than carbon dioxide over 20 years. The United States Geological Survey has previously listed Arctic hydrate destabilization as one of four most serious scenarios for abrupt climate change. The international team onboard the Russian research ship R/V Akademik Keldysh said most of the bubbles were currently dissolving in the water but methane levels at the surface were four to eight times what would normally be expected and this was venting into the atmosphere. The scientists -- who are part of a multi-year International Shelf Study Expedition -- stressed their findings were preliminary. The scale of methane releases will not be confirmed until they return, analyze the data and have their studies published in a peer-reviewed journal. But the discovery of potentially destabilized slope frozen methane raises concerns that a new tipping point has been reached that could increase the speed of global heating.
