edu.ucar.opensky::articles:18212 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:38:53.299005 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d73f4r79 Three decades of global methane sources and sinks 2013-10-01T00:00:00Z publication https://n2t.org/ark:/85065/d73f4r79 https://doi.org/10.1038/ngeo1955 Kirschke, S. author Bousquet, P. author Ciais, P. author Saunois, M. author Canadell, J. author Dlugokencky, E. author Bergamaschi, P. author Bergmann, D. author Blake, D. author Bruhwiler, L. author Cameron-Smith, P. author Castaldi, S. author Chevallier, F. author Feng, L. author Fraser, A. author Heimann, M. author Hodson, E. author Houweling, S. author Josse, V. author Fraser, P. author Krummel, P. author Lamarque, Jean-François author Langenfelds, R. author Le Quéré, C. author Naik, V. author O'Doherty, S. author Palmer, I. author Pison, I. author Plummer, D. author Poulter, B. author Prinn, R. author Rigby, M. author Ringeval, B. author Santini, M. author Schmidt, M. author Shindell, D. author Simpson, I. author Spahni, R. author Steele, L. author Strode, S. author Sudo, K. author Szopa, S. author van der Werf, G. author Voulgarakis, A. author Van Weele, M. author Weiss, R. author Williams, E. author Zeng, G. author UCAR/NCAR - Library publisher Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios — which differ in fossil fuel and microbial emissions — to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication An edited version of this article was published by the Nature Publishing Group. Copyright 2013 Author(s). None eng geoscientificInformation