Tuesday, August 5, 2008: 4:00 PM
103 AB, Midwest Airlines Center
Background/Question/Methods
More adequate estimates of soil methane consumption are needed as methanotrophy, next to atmospheric hydroxyl oxidation, plays a vital role in determining the atmospheric methane concentrations. Here we use a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to conduct a series of factorial simulations considering effects of changes of climate, land-cover and land-use, atmospheric methane concentrations, and atmospheric chemistry deposition on soil methane consumption on the globe.
Results/Conclusions
With an assumption of no land-use change and constant atmospheric methane concentrations, we estimate that the global soil consumption is 35 Tg CH4 per year in the 1990s and the consumption rate has increased 0.01 Tg CH4 per year during the last century. Our factorial simulations indicate that the changes of these factors alter the capacity of methanotrophs. In particular, the rising of atmospheric methane concentration increases soil methane consumption at 0.2 Tg CH4 per year during the last century. In contrast, our model simulation indicates that the
atmospheric ammonia deposition exerts minor effect on global methane consumption. Overall, our study suggests that factoring these influences into quantification of soil methane consumption will revise the existing estimates of methane burden in the atmosphere.
More adequate estimates of soil methane consumption are needed as methanotrophy, next to atmospheric hydroxyl oxidation, plays a vital role in determining the atmospheric methane concentrations. Here we use a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to conduct a series of factorial simulations considering effects of changes of climate, land-cover and land-use, atmospheric methane concentrations, and atmospheric chemistry deposition on soil methane consumption on the globe.
Results/Conclusions
With an assumption of no land-use change and constant atmospheric methane concentrations, we estimate that the global soil consumption is 35 Tg CH4 per year in the 1990s and the consumption rate has increased 0.01 Tg CH4 per year during the last century. Our factorial simulations indicate that the changes of these factors alter the capacity of methanotrophs. In particular, the rising of atmospheric methane concentration increases soil methane consumption at 0.2 Tg CH4 per year during the last century. In contrast, our model simulation indicates that the
atmospheric ammonia deposition exerts minor effect on global methane consumption. Overall, our study suggests that factoring these influences into quantification of soil methane consumption will revise the existing estimates of methane burden in the atmosphere.
