Old carbon reservoirs were not important in the deglacial methane budget
Michael Dyonisius, V. V. Petrenko, Andrew Smith, Quan Hua, Bin Yang, J. H. M. M. Schmitt, Jonas Beck, Barbara Seth, Michael Böck, Benjamin Hmiel, Isaac Vimont, J. A. Menking, Sarah Shackleton, Daniel Baggenstos, Thomas Bauska, Rachael H. Rhodes, Peter Sperlich, Ross Beaudette, Christina M. Harth, Michael Kalk, Edward J. Brook, Hubertus Fischer, Jeffrey P. Severinghaus, Ray F. Weiss
Abstract
Small burden from old sources Methane is a potent greenhouse gas with large natural sources, reservoirs, and sinks. Dyonisius et al. found that methane emissions from old, cold-region carbon reservoirs like permafrost and methane hydrates were minor during the last deglaciation (see the Perspective by Dean). They analyzed the carbon isotopic composition of atmospheric methane trapped in bubbles in Antarctic ice and found that methane emissions from those old carbon sources during the warming interval were small. They argue that this finding suggests that methane emissions in response to future warming likely will not be as large as some have suggested. Science , this issue p. 907 ; see also p. 846