Permafrost “tipping point” in less than 20 years?

I have been concerned about the effect of melting permafrost on the climate for quite some time, not least in the wake of encounters with scientists working in Greenland (this picture is Zackenberg, Greenland, 2009) and Alaska. Now research results published by the National Snow and Ice Data Centre (NSDIC) in Boulder, Colorado are indicating that there could be a “tipping point” or a “starting point”, as Professor Kevin Schaefer prefers to call it, in less than 20 years. That means a point when the vast areas of permafrost in Alaska, Canada, Siberia and parts of Europe go from being a “carbon sink” to a carbon source. The study indicates as much as two-thirds of the carbon frozen into the permafrost could be released.
There’s more info on the NSIDC website and on the ips news website, based on an interview with Prof. Schaefer. Not happy reading, but without big reductions in emissions, it will probably be impossible to prevent this. On top of that come the methane emissions, not included in the study. Methane is much more powerful than CO2 as a greenhouse gas.