Permafrost, Lakes, and Climate-Warming Methane Feedback: What is the Worst We Can Expect?
Author(s)
Gao, X.; Schlosser, C.A.; Sokolov, A.; Walter Anthony, K.; Zhuang, Q.; Kicklighter, D.W.; ... Show more Show less
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Permafrost degradation is likely enhanced by climate warming. Subsequent landscape subsidence and
hydrologic changes support expansion of lakes and wetlands. Their anaerobic environments can act as
strong emission sources of methane and thus represent a positive feedback to climate warming. Using an
integrated earth-system model framework, which considers the range of policy and uncertainty in climatechange
projections, we examine the influence of near-surface permafrost thaw on the prevalence of lakes,
its subsequent methane emission, and potential feedback under climate warming. We find that increases in
atmospheric CH4 and radiative forcing from increased lake CH4 emissions are small, particularly when
weighed against unconstrained human emissions. The additional warming from these methane sources,
across the range of climate policy and response, is no greater than 0.1 C by 2100. Further, for this temperature
feedback to be discernable by 2100 would require at least an order of magnitude larger methaneemission
response. Overall, the biogeochemical climate-warming feedback from boreal and Arctic lake
emissions is relatively small whether or not humans choose to constrain global emissions.
Description
http://globalchange.mit.edu/research/publications/2275
Date issued
2012-05Publisher
MIT Joint Program on the Science and Policy of Global Change
Citation
Report no. 218
Series/Report no.
Joint Program Report Series;218
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