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Climatic Effects of Methane Emissions from Alaska's North Slope

Paper Reviewed
Sweeney, C., Dlugokencky, E., Miller, C.E., Wofsy, S., Karion, A., Dinardo, S., Chang, R.Y.-W., Miller, J.B., Bruhwiler, L., Crotwell, A.M., Newberger, T., McKain, K., Stone, R.S., Wolter, S.E., Lang, P.E. and Tans, P. 2016. No significant increase in long-term CH4 emissions on the North Slope of Alaska despite significant increase in air temperature. Geophysical Research Letters 43: 6604-6611.

Lately, to quote Sweeney et al. (2016), "there has been significant speculation about how Arctic methane (CH4) emissions to the atmosphere might change as a result of anaerobic degradation of massive amounts of labile organic carbon that exist in the permafrost underlying large portions of the Arctic." And why the worry? Because, as they continue, "CH4 has almost 28 times the radiative impact of CO2 on a 100-year timescale," citing the assessment of Myhre et al. (2013), as is reported in Climate Change 2013: The Physical Science Basis.

In addition, the Sweeney et al. group of sixteen scientists reports that Tagesson et al. (2013) found only "very little sensitivity in CH4 emissions to surface air temperature changes in northeast Greenland from 1997 to 2010." And, therefore, they go on to conclude that "the observed short-term temperature sensitivity from the Arctic will have little impact on the global atmospheric CH4 budget in the long term if future trajectories evolve with the same temperature sensitivity." And that suggests there will be a whole lot less warming than the models are predicting.

Myhre, G., Shindell, D., Bréon, F.-M., Collins, W., Fuglestvedt, J., Huang, J., Koch, D., Lamarque, J.-F., Lee, D., Mendoza, B., Nakajima, T., Robock, A., Stephens, G., Takemura, T. and Zhang, H. 2013. Anthropogenic and natural radiative forcing. In Climate Change 2013: The Physical Science Basis.

Tagesson, T., Mastepanov, M., Molder, M., Tamstorf, M.P., Eklundh, L., Smith, B., Sigsgaard, D., Lund, M., Ekberg, A., Falk, J.M., Friborg, T., Christensen, T.R. and Strom, L. 2013. Modelling of growing season methane fluxes in a high-Arctic wet tundra ecosystem 1997-2010 using in situ and high-resolution satellite data. Tellus B Chemistry, Physics and Meteorology 65: doi:10.3402/tellusb.v65i0.19722.

Posted 21 December 2016