Quantifying carbon‐nitrogen feedbacks in the Community Land Model (CLM4)

[1] Recent studies indicate that nitrogen biogeochemistry affects the carbon cycle feedback in climate simulations. We use the Community Land Model version 4 (CLM4) with carbon-only and carbon-nitrogen biogeochemistry to assess the influence of nitrogen on the land carbon budget for 1973–2004. Carbon-only simulations show that the carbon gain from increasing atmospheric CO2 (the concentration-carbon feedback) is four times greater than the warming-induced carbon loss (the climate-carbon feedback) over the period 1973–2004. Nitrogen reduces both feedbacks compared with carbon-only biogeochemistry. The decrease in the concentration-carbon feedback is three times greater than the effect on the climate-carbon feedback. Thus, the influence of nitrogen on the CLM4 concentration-carbon feedback is of greater importance for near-term climate change simulations than its effect on the climate-carbon feedback. Furthermore, the land use carbon flux greatly exceeds these carbon-nitrogen biogeochemical feedbacks.

[1]  Andrei P. Sokolov,et al.  Consequences of Considering Carbon–Nitrogen Interactions on the Feedbacks between Climate and the Terrestrial Carbon Cycle , 2008 .

[2]  Robert L. Sanford,et al.  Nutrient Cycling in Moist Tropical Forest , 1986 .

[3]  Corinne Le Quéré,et al.  Trends in the sources and sinks of carbon dioxide , 2009 .

[4]  Atul K. Jain,et al.  Nitrogen attenuation of terrestrial carbon cycle response to global environmental factors , 2009 .

[5]  Julia C. Hargreaves,et al.  Long-term climate commitments projected with climate-carbon cycle models , 2008 .

[6]  J. Randerson,et al.  Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model , 2009 .

[7]  G. Asner,et al.  Nitrogen Cycles: Past, Present, and Future , 2004 .

[8]  S. Malyshev,et al.  The underpinnings of land‐use history: three centuries of global gridded land‐use transitions, wood‐harvest activity, and resulting secondary lands , 2006 .

[9]  S. Solomon.  The Physical Science Basis : Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2007 .

[10]  J. Randerson,et al.  Systematic assessment of terrestrial biogeochemistry in coupled climate–carbon models , 2009 .

[11]  W. Collins,et al.  The Community Climate System Model Version 3 (CCSM3) , 2006 .

[12]  W. McDowell,et al.  Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests , 1999 .

[13]  Pierre Friedlingstein,et al.  Terrestrial nitrogen feedbacks may accelerate future climate change , 2010 .

[14]  Pierre Friedlingstein,et al.  Carbon and nitrogen cycle dynamics in the O‐CN land surface model: 2. Role of the nitrogen cycle in the historical terrestrial carbon balance , 2010 .

[15]  Peter E. Thornton,et al.  Improvements to the Community Land Model and their impact on the hydrological cycle , 2008 .

[16]  Peter M. Vitousek,et al.  Litterfall, Nutrient Cycling, and Nutrient Limitation in Tropical Forests , 1984 .

[17]  A. Townsend,et al.  Nutrient additions to a tropical rain forest drive substantial soil carbon dioxide losses to the atmosphere , 2006, Proceedings of the National Academy of Sciences.

[18]  K. Oleson,et al.  Use of FLUXNET in the Community Land Model development , 2008 .

[19]  Peter E. Thornton,et al.  Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model , 2009 .

[20]  Peter E. Thornton,et al.  Assessing future nitrogen deposition and carbon cycle feedback using a multimodel approach: Analysis of nitrogen deposition , 2005 .

[21]  W. McDowell,et al.  Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests , 1999 .

[22]  J. Gregory,et al.  Quantifying Carbon Cycle Feedbacks , 2009 .

[23]  R. Schnur,et al.  Climate-carbon cycle feedback analysis: Results from the C , 2006 .

[24]  W. Collins,et al.  Global climate projections , 2007 .

[25]  Peter E. Thornton,et al.  Influence of carbon‐nitrogen cycle coupling on land model response to CO2 fertilization and climate variability , 2007 .

[26]  Benjamin Z. Houlton,et al.  Nitrogen constraints on terrestrial carbon uptake: Implications for the global carbon‐climate feedback , 2009 .