HR: 13:55h
AN: B33F-02 INVITED    [Abstracts]
TI: A synergistic effect of anthropogenic N and CO2 on land carbon uptake and its implications for global warming
AU: * Churkina, G
EM: churkina@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knohl str. 10, Jena, 07745, Germany
AU: * Churkina, G
EM: churkina@bgc-jena.mpg.de
AF: University of Michigan, School of Natural Resources and Environment, Dana Building, 440 Church str., Ann Arbor, MI 48109, United States
AU: Brovkin, V
EM: victor@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, P.O.Box 601203, Potsdam, 14412, Germany
AU: von Bloh, W
EM: bloh@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, P.O.Box 601203, Potsdam, 14412, Germany
AU: Trusilova, K
EM: ktrusilova@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knohl str. 10, Jena, 07745, Germany
AU: Jung, M
EM: mjung@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knohl str. 10, Jena, 07745, Germany
AU: Dentener, F
EM: frank.dentener@jrc.it
AF: European Commission, Institute for Environment and Sustainability, Joint Research Center, TP290, Ispra, 21020, Italy
AB: Increased carbon uptake of land in response to elevated atmospheric CO2 concentration and nitrogen deposition could offset the future rate of increase in CO2 levels and mitigate climate warming. None of the coupled climate- carbon cycle models used for analysis of climate-biogeochemistry feedbacks in the C4MIP intercomparison and the Fourth IPCC Assessment Report explicitly treats nitrogen cycle. Using a coupled model of climate, ocean, and land biogeochemistry driven by SRES scenarios of CO2 emissions and anthropogenic N deposition, we show that neither increasing nitrogen deposition nor physiological effect of CO2 alone can enhance global carbon uptake considerably to dampen the rising atmospheric CO2 concentration. Atmospheric nitrogen deposition and atmospheric CO2 have however a strong synergetic effect on the carbon uptake of land (~30 percent). We show that this synergetic effect increases strongly carbon uptake of land and has a potential to reduce atmospheric CO2 concentration by 30-40 ppmv by 2030. This potential depends on prevailing ecosystem types in areas with high nitrogen deposition and their responses to simultaneous increases in atmospheric CO2 and nitrogen deposition.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1622 Earth system modeling (1225)
DE: 1630 Impacts of global change (1225)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting