ACP Atmospheric Chemistry and Physics ACP Atmos. Chem. Phys. 1680-7324 Copernicus Publications Göttingen, Germany 10.5194/acp-8-3291-2008 Can we reconcile differences in estimates of carbon fluxes from land-use change and forestry for the 1990s? Ito A. 1 Penner J. E. 2 Prather M. J. 3 de Campos C. P. 4 Houghton R. A. 5 Kato T. 1 Jain A. K. 6 Yang X. 6 Hurtt G. C. 7 Frolking S. 7 Fearon M. G. 7 Chini L. P. 7 Wang A. 8 Price D. T. 9 Frontier Research Center for Global Change, JAMSTEC, Yokohama, Japan Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan, USA Earth System Science Department, University of California at Irvine, Irvine, California, USA Petrobras Research & Development Center, Rio de Janeiro, Brazil The Woods Hole Research Center, Woods Hole, Massachusetts, USA Department of Atmospheric Science, University of Illinois, Urbana, Illinois, USA Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USA Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada Natural Resources Canada, Northern Forestry Centre, Edmonton, Alberta, Canada 27 06 2008 8 12 3291 3310 Copyright: © 2008 A. Ito et al. 2008 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://acp.copernicus.org/articles/8/3291/2008/acp-8-3291-2008.html The full text article is available as a PDF file from https://acp.copernicus.org/articles/8/3291/2008/acp-8-3291-2008.pdf

The effect of Land Use Change and Forestry (LUCF) on terrestrial carbon fluxes can be regarded as a carbon credit or debit under the UNFCCC, but scientific uncertainty in the estimates for LUCF remains large. Here, we assess the LUCF estimates by examining a variety of models of different types with different land cover change maps in the 1990s. Annual carbon pools and their changes are separated into different components for separate geographical regions, while annual land cover change areas and carbon fluxes are disaggregated into different LUCF activities and the biospheric response due to CO<sub>2</sub> fertilization and climate change. We developed a consolidated estimate of the terrestrial carbon fluxes that combines book-keeping models with process-based biogeochemical models and inventory estimates and yields an estimate of the global terrestrial carbon flux that is within the uncertainty range developed in the IPCC 4th Assessment Report. We examined the USA and Brazil as case studies in order to assess the cause of differences from the UNFCCC reported carbon fluxes. Major differences in the litter and soil organic matter components are found for the USA. Differences in Brazil result from assumptions about the LUC for agricultural purposes. The effects of CO<sub>2</sub> fertilization and climate change also vary significantly in Brazil. Our consolidated estimate shows that the small sink in Latin America is within the uncertainty range from inverse models, but that the sink in the USA is significantly smaller than the inverse models estimates. Because there are different sources of errors at the country level, there is no easy reconciliation of different estimates of carbon fluxes at the global level. Clearly, further work is required to develop data sets for historical land cover change areas and models of biogeochemical changes for an accurate representation of carbon uptake or emissions due to LUC.

 References Achard, F., Eva, H. D., Stibig, H. J., Mayaux, P., Gallego, J., Richards, T., and Malingreau, J. P.: Determination of deforestation rates of the world's humid tropical forests, Science, 297, 999–1002, 2002. Achard, F., Eva, H. D., Mayaux, P., Stibig, H.-J., and Belward, A.: Improved estimates of net carbon emissions from land cover change in the tropics for the 1990s, Global Biogeochem. Cy., 18, GB2008, https://doi.org/10.1029/2003GB002142, 2004. Albani, M., Medvigy, D., Hurtt, G. C., and Moorcroft, P. R.: The contributions of land-use change, CO<sub>2</sub> fertilization, and climate variability to the Eastern US carbon sink, Global Change Biol., 12, 2370–2390, 2006. Amichev, B. Y. and Galbraith, J. M.: A revised methodology for estimation of forest soil carbon from spatial soils and forest inventory data sets, Environ. Manage., 33(Suppl 1), S74–S86, 2004. Amundson, R.: The carbon budget in soils. Annu. Rev. Earth Planet. Sci., 29, 535–562, 2001. Asner, G. P., Knapp, D. E., Broadbent, E. N., Oliveira, P. J. C., Keller, M., and Silva, J. N.: Selective Logging in the Brazilian Amazon, Science, 310, 480–482, 2005. Baker, D. F., Law, R. M., Gurney, K. R., et al.: TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO<sub>2</sub> fluxes, 1988–2003, Global Biogeochem. Cy., 20, GB1002, https://doi.org/10.1029/2004GB002439, 2006. Bartholomé, E. and Belward, A. S.: GLC2000: a new approach to global land cover mapping from Earth observation data, Int. J. Remote Sens., 26, 1959–1977, 2005. Betts, R. A., Falloon, P. D., Klein Goldewijk, K., and Ramankutty, N.: Biogeophysical effects of land use on climate: Model simulations of radiative forcing and large-scale temperature change, Agr. For. Metetorol., 142, 216–233, 2007. Birdsey, R. A., and Heath, L. S.: Carbon changes in US forests, in: Productivity of America's Forests and Climate Change, edited by: Joyce, L. A., USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, GTR-RM-271, Fort Collins, Colorado, USA, 56–70, 1995. Birdsey, R. and Heath, L. S.: Forest inventory data, models, and assumptions for monitoring carbon flux, in: Soil Carbon Sequestration and the Greenhouse Effect, SSSA Special Publication No 57. Soil Science Society of America, Madison, Wisconsin, USA, 125–135, 2001. Brazil Ministry of Science and Technology: Brazil's initial National Communication to the United Nations Framework Convention on Climate Change, report, General Coordination on Global Climate Change, Brazilia, Brazil, 2004. Brown, S. and Lugo, A. E.: Tropical secondary forests, J. Trop. Ecol., 6, 1–32, 1990. Brown, S., Lugo, A. E., and Chapman, J.: Biomass of tropical tree plantations and its implications for the global carbon budget, Can. J. Forest Res., 16 390–16 394, 1986. Caspersen, J. P., Pacala, S. W., Jenkins, J. C., Hurtt, G. C., Moorcroft, P. R., and Birdsey, R. A.: Contributions of land-use history to carbon accumulation in U.S. forests, Science, 290, 1148–1151, 2000. Chevallier, F., Breon, F.-M., and Rayner, P. J.: Contribution of the Orbiting Carbon Observatory to the estimation of CO<sub>2</sub> sources and sinks: Theoretical study in a variational data assimilation framework, J. Geophys. Res., 112, D09307, https://doi.org/10.1029/2006JD007375, 2007. Cramer, W., Bondeau, A., Woodward, F. I., et al.: Global response of terrestrial ecosystem structure and function to CO<sub>2</sub> and climate change: Results from six dynamic global vegetation models, Global Change Biol., 7, 357–373, 2001. Davidson E. A. and Janssens, I. A.: Temperature sensitivity of soil carbon decomposition and feedbacks to climate change, Nature, 440, 165–173, 2006. de Campos, C. P.: Historical land use change CO<sub>2</sub> emissions from land use change to agriculture and pasture and the climate change contributions by country - the Proposal by Brazil to the Climate Convention, Ph.D. thesis, Energy Planning Program of Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, 2007. de Campos C. P., Muylaert, M. S., and Rosa, L. P.: Historical CO<sub>2</sub> emission and concentrations due to land use change of croplands and pastures by country, Sci. Tot. Environ., 346, 149–155, 2005. DeFries, R. S., Houghton, R. A., Hansen, M. C., et al.: Carbon emissions from tropical deforestation and regrowth based on satellite observations for the 1980s and 1990s, Proc. Natl. Acad. Sci., U.S.A., 99, 14 256–14 261, 2002. Denman, K. L., Brasseur, G., Chidthaisong, A., et al.: Couplings between changes in the climate system and biogeochemistry, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, United Kingdom and New York, New York, USA, 2007. Enting, I. G.: Inverse Problems in Atmospheric Constituent Transport, Cambridge U. Press, USA, 2002. Eva, H. D., Belward A. S., De Miranda E., Di Bella C. M., Gond V., Huber O., Jones S., Sgrenzaroli M., and Fritz S.: A land cover map of South America, Global Change Biol., 10, 731–744, 2004. FAO: Forest resources assessment 1990; Tropical countries, FAO, Rome. Report FP-112, Italy, 1993. FAO: Assessing state and change in global forest cover: 2000 and beyond, Forest Resources Assessment Programme, Working Paper 31, FAO, Rome, Italy, 2000. FAO: Global Forest Resources Assessment 2005, FAO Forestry Paper 147, FAO, Rome Italy, 2006. FAOSTAT: Statistical Database of the United Nations Food and Agricultural Organization, http://apps.fao.org/, access: February 2004. FAOSTAT: Statistical Database of the United Nations Food and Agricultural Organization, http://apps.fao.org/, access: October 2005. Farquhar, G. D., Von Caemmerer, S., and Berry, J. A.: A biochemical model of photosynthetic CO<sub>2</sub> assimilation in leaves of C<sub>3</sub> species, Planta, 149, 78–90, 1980. Fearnside, P. M.: Global warming and tropical land-use change: Greenhouse gas emissions from biomass burning, decomposition and soils in forest conversion, shifting cultivation and secondary vegetation, Clim. Change, 46, 115–158, 2000. Friedlingstein, P., Cox, P., Betts, R., et al.: Climate-carbon cycle feedback analysis: Results from the C4MIP model intercomparison, J. Clim., 19, 3337–3353, 2006. Gerbig, C., Lin, J. C., Wofsy, S. C., Daube, B. C., Andrews, A. E., Stephens, B. B., Bakwin, P. S., and Grainger, C. A.: Toward constraining regional-scale fluxes of CO<sub>2</sub> with atmospheric observations over a continent: 2. Analysis of COBRA data using a receptor-oriented framework, J. Geophys. Res., 108, 4757, https://doi.org/10.1029/2003JD003770, 2003. Giardina, C. P. and Ryan, M. G.: Evidences that decomposition rates of organic carbon in mineral soil do not vary with temperature, Nature, 404, 858–861, 2000. Gruber, N. and Galloway, J. N.: An Earth-system perspective of the global nitrogen cycle, Nature, 451, 293–296, 2008 Gullison, R. E., Frumhoff, P. C., Canadell, J. G., et al.:, Tropical forests and climate policy, Science, 316, 985–986, 2007. Guo Y. Y., Gong, P., Amundson, R., and Yu, Q.: Analysis of factors controlling soil carbon in the conterminous United States, Soil Sci. Soc. Amer. J., 70, 601–612, 2006. Gurney, K. R., Law, R. M., Denning, A. S., et al.: Towards robust regional estimates of CO<sub>2</sub> sources and sinks using atmospheric transport models, Nature, 415, 626–630, 2002. Gurney, K. R., Law, R. M., Denning, A. S., et al.: Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks, Global Biogeochem. Cy., 18, GB1010, https://doi.org/10.1029/2003GB002111, 2004. Harmon, M. E. and Hua, C.: Coarse woody debris dynamics in two old-growth ecosystems, BioScience, 41, 604– 610, 1991. Harmon, M. E., Krankina, O. N., Yatskov, M., and Matthews, E.: Predicting broad-scale carbon stores of woody detritus from plot-level data, in: Assessment Methods for Soil Carbon, edited by: Lal, R., Kimble, J. M., Follett, R. F., and Stewart, B. A., Lewis Publishers, 533–552, Boca Raton, Fla, USA, 2001. Heath, L. S., Smith, J. E., and Birdsey, R. A.: The potential of US forest soils to sequester carbon and mitigate the greenhouse effect carbon trends in U. S. Forestlands, in: A Context for the Role of Soils in Forest Carbon Sequestration, edited by: Kimble, J. M., Heath, L. S., Birdsey, R. A., and Lal, R., Lewis Publishers, 383–394, Boca Raton, FL, USA, 2003. Heimann, M. and Reichstein, M.: Terrestrial ecosystem carbon dynamics and climate feedbacks, Nature, 451, 289–292, 2008 Houghton, R. A.: Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use 1850–2000, Tellus, Ser. B, 55, 378– 390, 2003. Houghton, R. A. and Hackler, J. L.: Emissions of carbon from forestry and land-use change in tropical Asia, Global Change Biol., 5, 481–492, 1999. Houghton, R. A. and Hackler, J. L.: Sources and sinks of carbon from land-use change in China, Global Biogeochem. Cy., 17, 1034, https://doi.org/10.1029/2002GB001970, 2003. Houghton, R. A., Hackler, J. L., and Lawrence, K. T.: The US carbon budget: Contributions from land-use change, Science 285, 574–578, 1999. Houghton, R. A. and Ramakrishna, K.: A review of national emissions inventories from select non-Annex I countries: Implications for counting sources and sinks of carbon, Ann. Rev. Energy Environ., 24, 571–605, 1999. Houghton, R. A., Hobbie, J. E., Melillo, J. M., Moore, B., Peterson, B. J., Shaver, G. R., and Woodwell, G. M.: Changes in the carbon content of terrestrial biota and soils between 1860 and 1980: A net release of CO<sub>2</sub> to the atmosphere. Ecol. Monogr. 53, 235–262, 1983. Houghton R. A., Skole, D. L., Nobre, C. A., Hackler, J. L., Lawrence K. T., and Chomentowski, W H.: Annual fluxes of carbon from deforestation and regrowth in the Brazilian Amazon, Nature, 403, 301–304, 2000. House, J. I., Prentice, I. C., Ramankutty, N., Houghton, R. A., and Heimann, M.: Reconciling apparent inconsistencies in estimates of terrestrial CO<sub>2</sub> sources and sinks, Tellus, Ser. B, 55, 345– 363, 2003. Hurtt, G. C., Pacala, S. W., Moorcroft, P. R., Caspersen, J., Shevliakova, E., Houghton, R. A., and Moore III, B.: Projecting the future of the U.S. carbon sink, Proc. Natl. Acad. Sci., USA, 99, 1389–1394, 2002. Hurtt G. C., Frolking, S., Fearon, M. G., Moore, B., Shevliakova, E., Malyshev, S., Pacala, S. W., and Houghton, R. A.: The underpinnings of land-use history: Three centuries of global gridded land-use transitions, wood-harvest activity, and resulting secondary lands, Global Change Biol., 12, 1208–1229, 2006. IPCC: Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories. IPCC/OECD/IEA, Paris, France, 1997. IPCC: Land Use, Land-Use Change and Forestry: A special report of Working Group III of the Intergovernmental Panel on Climate Change, edited by: Watson, R. T., Noble, I. R., Bolin, B., Ravindranath, N. H., Verardo, D. J., and Dokken D. J., Cambridge University Press, Cambridge, UK, 2000. IPCC: Good Practice Guidance for Land Use, Land-Use Change, and Forestry. The Intergovernmental Panel on Climate Change, National Greenhouse Gas Inventories Programme, edited by: Penman, J., Gytarsky, M., Hiraishi, T., et al., http://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf.htm, 2003. IPCC: 2006 IPCC guidelines for National Greenhouse Gas Inventories, Agriculture, Forestry and Other Land Use, edited by: Eggleston, S., Buendia, L., Miwa, K., Ngara, T., and Tanabe, K., http://www.ipcc-nggip.iges.or.jp/public/2006gl/vol4.html, 2006. Ito, A., Ito, A., and Akimoto, H.: Seasonal and interannual variations in CO and BC emissions from open biomass burning in Southern Africa during 1998–2005, Global Biogeochem. Cy., 21, GB2011, https://doi.org/10.1029/2006GB002848, 2007a. Ito, A., Sudo, K., Akimoto, H., Sillman, S., and Penner, J. E.: Global modeling analysis of tropospheric ozone and its radiative forcing from biomass burning emissions in the twentieth century, J. Geophys. Res., 112, D24307, https://doi.org/10.1029/2007JD008745, 2007b. Ito, A. H., Muraoka, H., Koizumi, H., Saigusa, N., Murayama, S., and Yamamoto, S.: Seasonal variation in leaf properties and ecosystem carbon budget in a cool-temperate deciduous broad-leaved forest: Simulation analysis at Takayama site, Japan, Ecol. Res., 21, 137–149, 2006. Ito, A. H. and Oikawa, T.: A simulation model of the carbon cycle in land ecosystems (Sim-CYCLE): A description based on dry-matter production theory and plot-scale validation Source, Ecol. Model, 151, 143–176, 2002. Jacobson, A. R., Mikaloff Fletcher, S. E., Gruber, N., Sarmiento, J. L., and Gloor, M.: A joint atmosphere-ocean inversion for surface fluxes of carbon dioxide: 1. Methods and global-scale fluxes, Global Biogeochem. Cy., 21, GB1019, https://doi.org/10.1029/2005GB002556, 2007. Jain, A. K., Tao, Z., Yang, X., and Gillespie, C.: Estimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NO$_x)$ and CO<sub>2</sub>, J. Geophys. Res., 111, D06304, https://doi.org/10.1029/2005JD006237, 2006. Jain, A. K. and Yang, X.: Modeling the effects of two different land cover change data sets on the carbon stocks of plants and soils in concert with CO<sub>2</sub> and climate change, Global Biogeochem. Cy., 19, GB2015, https://doi.org/10.1029/2004GB002349, 2005. Janzen, H.: Carbon cycling in earth systems a soil science perspective. Agr. Ecosyst. Environ., 104, 399–417, 2004. Jenkinson, D. S.: The turnover of organic carbon and nitrogen in soil, Philos. Trans. R. Soc. London, Ser. B, 329, 361–368, 1990. Jones C., McConnell, C., Coleman, K., Cox, P., Falloon, P., Jenkinson, D., Powlson, D.: Global climate change and soil carbon stocks; predictions from two contrasting models for the turnover of organic carbon in soil, Global Change Biol., 11, 154–166, 2005. Kawamiya, M., Yoshikawa, C., Sato, H., Sudo, K., Watanabe, S., and Matsuno, T.: Development of an integrated earth system model on the Earth Simulator, J. Earth Simurator, 4, 18–30, 2005. Krankina, O. N., Harmon, M. E., Kukuev, Y. A., et al.: Coarse woody debris in forest regions of Russia, Can. J. For. Res., 32, 768–778, 2002. Klein Goldewijk, K.: Estimating global land use change over the past 300 years: The HYDE database, Global Biogeochem. Cy., 15, 417–433, 2001. Klein Goldewijk, K. and Ramankutty, N.: Land cover change over the last three centuries due to human activities: The availability of new global data sets, GeoJournal, 61, 335–344, 2004. Knorr W., Prentice, I. C., House, J. I., and Holland, E. A.: Long-term sensitivity of soil carbon turnover to warming, Nature, 433, 298–301, 2005. Luo, Y., Wan, S., Hui, D., and Wallace, L. L.: Acclimatization of soil respiration to warming in a tall grass prairie, Nature, 413, 622–625, 2001. Matthews, E.: Global vegetation and land use: New high-resolution data bases for climate studies, J. Clim. Appl. Meteorol., 22, 474–487, 1983. Matthews, E.: Global litter production, pools, and turnover times: Estimates from measurement data and regression models, J. Geophys. Res., 102, 18 771–18 800, 1997. McGuire, A. D., Sitch, S., Clein, J. S., et al.: Carbon balance of the terrestrial biosphere in the twentieth century: Analyses of CO<sub>2</sub>, climate and land use effects with four process based ecosystem models, Global Biogeochem. Cy. 15, 183–206, 2001. Nepstad, D. C, Verissimo, A., Alencar, A., Nobre, C., Lima, E., Lefebvre, P., Schlesinger, P., Potter, C., Moutinho, P., Mendoza, E., Cochrane, M., and Brooks, V.: Large-scale impoverishment of Amazonian forests by logging and fire, Nature, 398, 505–508, 1999. Norby, R. J., DeLucia, E. H., Gielen, B., et al.: Forest response to elevated CO<sub>2</sub> is conserved across a broad range of productivity, Proc. Natl. Acad. Sci., USA, 102, 18 052–18 056, 2005. Oliveira, P. J. C., Asner, G. P., Knapp, D. E., Almeyda, A., Galván-Gildemeister, R., Keene, S., Raybin, R. F., and Smith, R. C.: Land-use allocation protects the Peruvian Amazon, Science, 31, 1233–1236, 2007. Olivier, J. G. J., and Berdowski, J. J. M.:Global emissions sources and sinks, in: The Climate System, Berdowski, J., Guicherit, R., and Heij, B. J. (Eds.), A. A. Balkema Publishers/Swets & Zeitlinger Publishers, Lisse, The Netherlands, 33–78, 2001. Pak, B. C. and Prather, M. J.: CO<sub>2</sub> source inversions using satellite observations of the upper troposphere, Geophys. Res. Lett., 28, 4571–4574, 2001. Pacala, S. W., Hurtt, G. C., Baker, D., et al.: Consistent land- and atmosphere-based US carbon sink estimates, Science, 292, 2316–2320, 2001. Pastor, J. and Post, W. M.: Development of a linked forest productivity-soil process model, Tech. Rep. ORNL/TM-9519, Oak Ridge Natl. Lab., Oak Ridge, Tenn, USA, 1985. Patra, P. K., Gurney, K. R., Denning, A. S., et al.: Sensitivity of inverse estimation of annual mean CO<sub>2</sub> sources and sinks to ocean-only sites versus all-sites observational networks, Geophys. Res. Lett., 33, L05814, https://doi.org/10.1029/2005GL025403, 2006. Pietsch, S. A. and Hasenauer, H.: Evaluating the self-initialization procedure for large-scale ecosystem models, Global Change Biol., 12, 1658–1669, 2006. Ramankutty, N. and Foley, J.: Characterizing patterns of global land use: An analysis of global croplands data, Global Biogeochem. Cy., 12, 667–685, 1998. Ramankutty, N. and Foley, J. A.: Estimating historical changes in global land cover: Croplands from 1700 to 1992, Global Biogeochem. Cy., 13, 997–1027, 1999. Ramankutty. N., Gibbs, H. K., Achard, F., DeFries, R., Foley, J. A., and Houghton, R. A.: Challenges to estimating carbon emissions from tropical deforestation, Global Change Biol., 13, 51–66, 2007. Reich, P. B., Hobbie, S. E., Lee, T., et al.: Nitrogen limitation constrains sustainability of ecosystem response to CO<sub>2</sub>, Nature, 440, 922–925, 2006. Sarrat, C., Noilhan, J., Lacarrèreet P., et al.: Atmospheric CO<sub>2</sub> modeling at the regional scale: Application to the CarboEurope Regional Experiment, J. Geophys. Res., 112, D12105, https://doi.org/10.1029/2006JD008107, 2007. Schulze, E.-D., Mollicone D., Achard F., Matteucci G., Federici S., Eva H. D., and Valentini R.: Making deforestation pay under the Kyoto protocol?, Science, 299, 1669, 2003. Smith, J. E., Heath, L. S., and Woodbury, P. B.: How to estimate forest carbon for large areas from inventory data, J. For., 102, 25–31, 2004a. Smith, W. B., Miles, P. D., Vissage, J. S., and Pugh, S. A.: Forest Resources of the United States, 2002. General Technical Report NC-241, US Department of Agriculture Forest Service, North Central Research Station, St. Paul, MN, USA, 2004b. Stephens, B. B., Gurney, K. R., Tans, P. P., et al.: Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO<sub>2</sub>, Science, 316, 1732–1735, 2007.Sitch, S., Cox, P. M., Collins, W. J., and Huntingford, C.: Indirect radiative forcing of climate change through ozone effects on the land-carbon sink, Nature, 448, 791–794, 2007. Takata, K., Emori, S., and Watanabe, T.: Development of the minimal advanced of the surface interaction and runoff, Global Planetary Change, 38, 209–222, 2003. Thornthwaite, C. W. and Mather, J. R.: Instructions and tables for computing potential evapotranspiration and the water balance, Publ. Climatol., 10, 183–311, 1957. Thornton, P. E., Lamarque, J.-F., Rosenbloom, N. A., and Mahowald, N. M.: Influence of carbon-nitrogen cycle coupling on land model response to CO<sub>2</sub> fertilization and climate variability, Global Biogeochem. Cy., 21, GB4018, https://doi.org/10.1029/2006GB002868, 2007. US Environmental Protection Agency: Inventory of U.S. greenhouse gas emissions and sinks: 1990–2005, report, Off. of Atmos. Programs, Washington, D. C., USA, 2007. USDA: State Soil Geographic (STATSGO) Data Base Data use information. Miscellaneous Publication Number 1492, National Soil Survey Center, Natural Resources Conservation Service, US Department of Agriculture, Fort Worth, TX, USA, 1991. UNFCCC (United Nations Framework Convention on Climate Change): Sixth compilation and synthesis of initial national communications from Parties not included in Annex I to the Convention. Note by the Secretariat, Subsidiary Body for Implementation, FCCC/SBI/2005/18, Montreal, 2005. UNFCCC (United Nations Framework Convention on Climate Change): National greenhouse gas inventory data for the period 1990–2005. Note by the Secretariat, Subsidiary Body for Implementation, FCCC/SBI/2007/30, Bali, 2007. van Aardenne, J. A., Dentener, F. J., Olivier, J. G. J., Klein Goldewijk, C. G. M., and Lelieveld, J: A 1$^\circ\times1^\circ$ resolution data set of historical anthropogenic trace gas emissions for the period 1890–1990, Global Biogeochem. Cy., 15, 909–928, 2001. van der Werf, G. R., Randerson, J. T., Collatz, G. J., Giglio, L., Kasibhatla, P. S., Arellano, Jr. A. F., Olsen, S. C., and Kasischke, E. S.: Continental-scale partitioning of fire emissions during the 1997 to 2001 El Niño/La Niña period, Science, 303, 73–76, 2004. Wang, A., Price, D. T., and Arora, V.: Estimating changes in global vegetation cover (1850–2100) for use in climate models, Global Biogeochem. Cy., 20, GB3028, https://doi.org/10.1029/2005GB002514, 2006. Wang, J.-W., Denning, A. S., Lu, L., Baker, I. T., Corbin, K. D., and Davis, K. J.: Observations and simulations of synoptic, regional, and local variations in atmospheric CO<sub>2</sub>, J. Geophys. Res., 112, D04108, https://doi.org/10.1029/2006JD007410, 2007. Woodbury, P. B., Heath, L. S., and Smith, J. E.: Effects of land use change on soil carbon cycling in the conterminous United States from 1900 to 2050, Global Biogeochem. Cy., 21, GB3006, https://doi.org/10.1029/2007GB002950, 2007.