Risk of Warming via Methane Release by Permafrost Degradation
Gao, X., Schlosser, C.A., Sokolov, A., Anthony, K.W., Zhuang, Q. and Kicklighter, D. 2013. Permafrost degradation and methane: low risk of biogeochemical climate-warming feedback. Environmental Research Letters 8: 10.1088/1748-9326/8/3/035014.
To better evaluate this line of reasoning, Gao et al. set out to employ an integrated earth-system model framework to "examine the degradation of near-surface permafrost, temporal dynamics of inundation (lakes and wetlands) induced by hydro-climatic change, subsequent methane emission, and potential climate feedback." In doing so, the six scientists found that "increases in atmospheric CH4 and its radiative forcing, which result from the thawed, inundated emission sources, are small, particularly when weighed against human emissions," while adding "the additional warming, across the range of climate policy and uncertainties in the climate-system response, would be no greater than 0.1°C by 2100." What is more, they calculate that "for this temperature feedback to be doubled (to approximately 0.2°C) by 2100, at least a 25-fold increase in the methane emission that results from the estimated permafrost degradation would be required." In light of such findings, it appears the so-called methane problem is actually no problem at all.
Anisimov, O.A. 2007. Potential feedback of thawing permafrost to the global climate system through methane emission. Environmental Research Letters 2: 10.1088/1748-9326/2/4/045016.
Shindell, D., Walter, B.P. and Faluvegi, G. 2004. Impacts of climate change on methane emissions from wetlands. Geophysical Research Letters 31: 10.1088/1748-9326/8/3/035014.
Walter, K.M., Zimov, S.A., Chanton, J.P., Verbyla, D. and Chapin III, F.S. 2006. Methane bubbling from Siberian thaw lakes as positive feedback to climate warming. Nature 443: 71-75.
Zimov, S.A., Voropaev, Y.V., Semiletov, I.P., Davidov, S.P., Prosiannikov, S.F., Chapin, F.S., Chapin, M.C., Trumbore, S. and Tyler, S. 1997. North Siberian lakes: a methane source fuelled by Pleistocene carbon. Science 277: 800-802.