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Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model

Naturevolume 408pages184187 (2000) | Download Citation


  • An Erratum to this article was published on 07 December 2000


The continued increase in the atmospheric concentration of carbon dioxide due to anthropogenic emissions is predicted to lead to significant changes in climate1. About half of the current emissions are being absorbed by the ocean and by land ecosystems2, but this absorption is sensitive to climate3,4 as well as to atmospheric carbon dioxide concentrations5, creating a feedback loop. General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon-cycle models that do not include climate change6. Here we present results from a fully coupled, three-dimensional carbon–climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century. We find that under a ‘business as usual’ scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, the ocean uptake rate of 5 Gt C yr-1 is balanced by the terrestrial carbon source, and atmospheric CO2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models2, resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback.

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  1. 1

    Houghton, J. T. et al. (eds) Climate Change 1995: The Science of Climate Change (Cambridge Univ. Press, Cambridge, 1996).

  2. 2

    Schimel, D. et al. in Climate Change 1995: The Science of Climate Change Ch. 2 (eds Houghton, J. T. et al.) 65–131 (Cambridge Univ. Press, Cambridge, 1995).

  3. 3

    Sarmiento, J., Hughes, T., Stouffer, R. & Manabe, S. Simulated response of the ocean carbon cycle to anthropogenic climate warming. Nature 393, 245–249 ( 1998).

  4. 4

    Cao, M. & Woodward, F. I. Dynamic responses of terrestrial ecosystem carbon cycling to global climate change. Nature 393, 249–252 (1998).

  5. 5

    Betts, R. A., Cox, P. M., Lee, S. E. & Woodward, F. I. Contrasting physiological and structural vegetation feedbacks in climate change simulations. Nature 387, 796–799 (1997).

  6. 6

    Enting, I., Wigley, T. & Heimann, M. Future Emissions and Concentrations of Carbon Dioxide; Key Ocean/Atmosphere/Land Analyses (Technical Paper 31, Division of Atmospheric Research, CSIRO, Melbourne, 1994).

  7. 7

    Gordon, C. et al. The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments. Clim. Dyn. 16, 147–168 (2000).

  8. 8

    Palmer, J. R. & Totterdell, I. J. Production and export in a global ocean ecosystem model. Deep-Sea Res. (in the press).

  9. 9

    Wilson, M. F. & Henderson-Sellers, A. A global archive of land cover and soils data for use in general circulation climate models. J. Clim. 5, 119–143 ( 1985).

  10. 10

    Zinke, P. J., Stangenberger, A. G., Post, W. M., Emanuel, W. R. & Olson, J. S. Worldwide Organic Soil Carbon and Nitrogen Data (NDP-018, Carbon Dioxide Information Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 1986).

  11. 11

    Cramer, W. et al. Global response of terrestrial ecosystem structure and function to CO2 and climate change: results from six dynamic global vegetation models. Glob. Change Biol. (in the press).

  12. 12

    VEMAP Members. Vegetation/ecosystem modelling and analysis project: comparing biogeography and biogeochemistry models in a continental-scale study of terrestrial responses to climate change and CO2 doubling. Glob. Biogeochem. Cycles 9, 407–437 (1995).

  13. 13

    Longhurst, A., Sathyendranath, S., Platt, T. & Caverhill, C. An estimate of global primary production in the ocean from satellite radiometer data. J. Plank. Res. 17, 1245– 1271 (1995).

  14. 14

    Field, C., Behrenfeld, M., Randerson, J. & Falkowski, P. Primary production of the biosphere: integrating terrestrial and oceanic components. Science 281, 237–240 (1998).

  15. 15

    Antoine, D., Andre, J.-M. & Morel, A. Oceanic primary production 2. Estimation at global scale from satellite (Coastal Zone Color Scanner) chlorophyll. Glob. Biogeochem. Cycles 10, 57–69 (1996).

  16. 16

    Tian, H. et al. Effects of interannual climate variability on carbon storage in Amazonian ecosystems. Nature 396, 664 –667 (1998).

  17. 17

    Keeling, C. D., Whorf, T., Whalen, M. & der Plicht, J. V. Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980. Nature 375, 666–670 ( 1995).

  18. 18

    Houghton, J. T., Callander, B. A. & Varney, S. K. (eds) Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment (Cambridge Univ. Press, Cambridge, 1992).

  19. 19

    Nicholls, N. et al. in Climate Change 1995: The Science of Climate Change Ch. 3 (eds Houghton, J. T. et al.) (Cambridge Univ. Press, Cambridge, 1996).

  20. 20

    Mitchell, J. F. B., Johns, T. C., Gregory, J. M. & Tett, S. F. B. Climate response to increasing levels of greenhouse gases and sulphate aerosols. Nature 376, 501– 504 (1995).

  21. 21

    Wood, R. A., Keen, A. B., Mitchell, J. F. B. & Gregory, J. M. Changing spatial structure of the thermohaline circulation in response to atmospheric CO2 forcing in a climate model. Nature 399, 572–575 (1999).

  22. 22

    Sarmiento, J. & Quere, C. L. Oceanic carbon dioxide uptake in a model of century-scale global warming. Nature 274 , 1346–1350 (1996).

  23. 23

    Giardina, C. & Ryan, M. Evidence that decomposition rates of organic carbon in mineral soil do not vary with temperature. Nature 404, 858–861 ( 2000).

  24. 24

    Orr, J. C. in Ocean Storage of Carbon Dioxide, Workshop 3: International Links and Concerns (ed. Ormerod, W.) 33–52 (IEA R&D Programme, CRE Group Ltd, Cheltenham, UK, 1996).

  25. 25

    Cox, P. M., Huntingford, C. & Harding, R. J. A canopy conductance and photosynthesis model for use in a GCM land surface scheme. J. Hydrol. 212–213 , 79–94 (1998).

  26. 26

    Cox, P. M. et al. The impact of new land surface physics on the GCM simulation of climate and climate sensitivity. Clim. Dyn. 15, 183–203 (1999).

  27. 27

    Collatz, G. J., Ball, J. T., Grivet, C. & Berry, J. A. Physiological and environmental regulation of stomatal conductance, photosynthesis and transpiration: a model that includes a laminar boundary layer. Agric. Forest Meteorol. 54, 107–136 ( 1991).

  28. 28

    Collatz, G. J., Ribas-Carbo, M. & Berry, J. A. A coupled photosynthesis-stomatal conductance model for leaves of C4 plants. Aust. J. Plant Physiol. 19 , 519–538 (1992).

  29. 29

    Raich, J. & Schlesinger, W. The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate. Tellus B 44, 81–99 ( 1992).

  30. 30

    McGuire, A. et al. Interactions between carbon and nitrogen dynamics in estimating net primary productivity for potential vegetation in North America. Glob. Biogeochem. Cycles 6, 101–124 (1992).

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We thank J. Mitchell and G. Jenkins for comments on earlier versions of the manuscript. This work was supported by the UK Department of the Environment, Transport and the Regions.

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  1. Hadley Centre, The Met Office, Bracknell, RG12 2SY, Berkshire, UK

    • Peter M. Cox
    • , Richard A. Betts
    • , Chris D. Jones
    •  & Steven A. Spall
  2. Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH, UK

    • Ian J. Totterdell


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Correspondence to Peter M. Cox.

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