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Consumption of atmospheric methane by soils: A process‐based model
Author(s) -
Ridgwell Andy J.,
Marshall Stewart J.,
Gregson Keith
Publication year - 1999
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/1998gb900004
Subject(s) - sink (geography) , methane , soil water , environmental science , ecosystem , atmospheric sciences , limiting , flux (metallurgy) , soil science , environmental chemistry , atmospheric methane , anaerobic oxidation of methane , global warming , climate change , chemistry , ecology , biology , geology , organic chemistry , engineering , mechanical engineering , geography , cartography
A process‐based model for the consumption of atmospheric methane (CH 4 ) by soils was developed to identify the most important factors affecting uptake rates and to determine whether the current uncertainties in the estimated size of the global soil sink might be reduced. Descriptions of diffusion and microbial oxidation processes, which together determine the CH 4 flux, were included. The results suggest that the global sink strength lies within the range 20–51 Tg yr −1 CH 4 , with a preferred value of 38 Tg yr −1 CH 4 . Dry tropical ecosystems account for almost a third of this total. Here microbial activity rather than diffusion is limiting uptake. It is also in these areas that the impact of any intensification in agriculture will be the most pronounced, with a possible future reduction in uptake in excess of 3 Tg yr −1 CH 4 . This is in contrast to the overall impact of global warming, which is expected to leave the size of the global soil sink relatively unchanged.