Scientists find dramatic increase in Arctic methane release
January 7th, 2010Scientists have uncovered a dramatic increase in methane gas seeping from the Arctic seabed.
A team of scientists led by Igor Semiletov from the University of Alaska at Fairbanks measured carbon fluxes around the north of Russia. Semiletov tells what they found:
Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be].
Methane seepage recorded last summer was the highest ever measured in the Arctic Ocean.
Higher concentrations of atmospheric methane are contributing to global temperature rise; this in turn is projected to cause further permafrost melting and the release of yet more methane in a feedback loop. A worst-case scenario is one where the feedback passes a tipping point and billions of tonnes of methane are released suddenly, resulting in rapid increases in global temperatures and mass extinction of species.
Siberia’s shallow shelf areas act as a giant frozen depository of carbon in the form of CO2 and methane (often stored as compacted solid gas hydrates). This undersea permafrost was until recently considered to be stable, and much of the gas that did escape was absorbed by the sea. But Semiletov’s team found, due to the shallow depth of arctic shelves, methane is reaching the atmosphere without reacting to become CO2 or dissolving in the ocean.
Methane measured in the atmosphere around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.
Estimates of the amount of carbon trapped in shelf permafrost are in the range of 1,600 billion tonnes – roughly twice as much carbon as in the atmosphere now. The release of this carbon from destabilized ocean sediments and permafrost would have catastrophic effect on our climate and life on Earth.