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Role of regional wetland emissions in atmospheric methane variability
Author(s) -
McNorton J.,
Gloor E.,
Wilson C.,
Hayman G. D.,
Gedney N.,
ComynPlatt E.,
Marthews T.,
Parker R. J.,
Boesch H.,
Chipperfield M. P.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070649
Subject(s) - atmospheric methane , methane , environmental science , methane emissions , wetland , greenhouse gas , atmospheric sciences , climatology , meteorology , geology , geography , oceanography , ecology , biology
Abstract Atmospheric methane (CH 4 ) accounts for ~20% of the total direct anthropogenic radiative forcing by long‐lived greenhouse gases. Surface observations show a pause (1999–2006) followed by a resumption in CH 4 growth, which remain largely unexplained. Using a land surface model, we estimate wetland CH 4 emissions from 1993 to 2014 and study the regional contributions to changes in atmospheric CH 4 . Atmospheric model simulations using these emissions, together with other sources, compare well with surface and satellite CH 4 data. Modeled global wetland emissions vary by ±3%/yr ( σ = 4.8 Tg), mainly due to precipitation‐induced changes in wetland area, but the integrated effect makes only a small contribution to the pause in CH 4 growth from 1999 to 2006. Increasing temperature, which increases wetland area, drives a long‐term trend in wetland CH 4 emissions of +0.2%/yr (1999 to 2014). The increased growth post‐2006 was partly caused by increased wetland emissions (+3%), mainly from Tropical Asia, Southern Africa, and Australia.