A. A. Bloom et al., Science, 327(5963), Large-scale controls of methanogenesis inferred from methane and gravity spaceborne data

Science (15 January 2010), Vol. 327, No. 5963, pp. 322–325; DOI: 10.1126/science.1175176

Reports

Large-scale controls of methanogenesis inferred from methane and gravity spaceborne data

A. Anthony Bloom,¹ Paul I. Palmer,^1,* Annemarie Fraser,¹ David S. Reay,¹ and Christian Frankenberg²

Abstract

Wetlands are the largest individual source of methane (CH₄), but the magnitude and distribution of this source are poorly understood on continental scales. We isolated the wetland and rice paddy contributions to spaceborne CH₄ measurements over 2003–2005 using satellite observations of gravity anomalies, a proxy for water-table depth , and surface temperature analyses T_S. We find that tropical and higher-latitude CH₄ variations are largely described by and T_S variations, respectively. Our work suggests that tropical wetlands contribute 52 to 58% of global emissions, with the remainder coming from the extra-tropics, 2% of which is from Arctic latitudes. We estimate a 7% rise in wetland CH₄ emissions over 2003–2007, due to warming of mid-latitude and Arctic wetland regions, which we find is consistent with recent changes in atmospheric CH₄.

¹ School of GeoSciences, University of Edinburgh, Edinburgh, U.K.
² SRON Netherlands Institute for Space Research, Utrecht, The Netherlands. 


^*Correspondence e-mail: pip@ed.ac.uk

Link:  http://www.sciencemag.org/cgi/content/abstract/327/5963/322