An anonymous reader writes: 'No alarm' says a scientist although the sci-fi scenario of melting of methane hydrates seems to be going on in the Arctic seabed. Methane — a strong greenhouse gas — is stored in a large quantities as compacted solid gas hydrates in the Siberia's shallow shelf areas. From the article: "methane measured in the atmosphere [during the last year's expedition] around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.". The release of all methane from the region could accelerate global warming, in the worst case the process could pass a tipping point and become catastrophic leading to a rapid global temperature rise. According to the article it would not be the first time in Earth's history.