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Relative impacts of human-induced climate change and natural climate variability


Assessments of the regional impacts of human-induced climate change on a wide range of social and environmental systems are fundamental for determining the appropriate policy responses to climate change1,2,3. Yet regional-scale impact assessments are fraught with difficulties, such as the uncertainties of regional climate-change prediction4, the specification of appropriate environmental-response models5, and the interpretation of impact results in the context of future socio-economic and technological change6. The effects of such confounding factors on estimates of climate-change impacts have only been poorly explored3,4,5,6,7. Here we use results from recent global climate simulations8 and two environmental response models9,10 to consider systematically the effects of natural climate variability (30-year timescales) and future climate-change uncertainties on river runoff and agricultural potential in Europe. We find that, for some regions, the impacts of human-induced climate change by 2050 will be undetectable relative to those due to natural multi-decadal climate variability. If misleading assessments of—and inappropriate adaptation strategies to—climate-change impacts are to be avoided, future studies should consider the impacts of natural multi-decadal climate variability alongside those of human-induced climate change.

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Figure 1: Relative impact of climate change on runoff.
Figure 2: Relative changes in mean wheat yield at a national scale.

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  1. Parry, M. L., Carter, T. R. & Hulme, M. What is a dangerous climate change? Glob. Environ. Change, 6, 1–6 (1996).

    Article  Google Scholar 

  2. Wigley, T. M. L., Richels, R. & Edmonds, J. A. Economic and environmental choices in the stabilization of atmospheric CO2 concentrations. Nature 379, 240–243 (1996).

    Article  ADS  CAS  Google Scholar 

  3. IPCC (eds Watson, R. T., Zinyowera, M. C., Moss, R. H. & Dokken, D. J. The Regional Impacts of Climate Change: an Assessment of Vulnerability(Cambridge Univ. Press, (1998).

    Google Scholar 

  4. Kittel, T. G. F., Giorgi, F. & Meehl, G. A. Intercomparison of regional biases and doubled CO2—sensitivity of coupled atmosphere–ocean general circulation model experiments. Clim. Dyn. 14, 1–15 (1998).

    Article  Google Scholar 

  5. Shugart, H. H. & Smith, T. M. Areview of forest patch models and their applications to global change research. Clim. Change 34, 131–153 (1996).

    Article  ADS  Google Scholar 

  6. Dowlatabadi, H. Assessing the health impacts of climate change. Clim. Change 35, 137–144 (1997).

    Google Scholar 

  7. Watson, R. T., Zinyowera, M. C. & Moss, R. H. (eds Climate Change 1995: Impacts, Adaptations and Mitigation of Climate Change: Scientific–Technical Analyses(Cambridge Univ. Press, (1996).

    Google Scholar 

  8. Mitchell, J. F. B. & Johns, T. C. On the modification of global warming by sulphate aerosols. J.Clim. 10, 245–267 (1997).

    Article  ADS  Google Scholar 

  9. Arnell, N. W. The effect of climate change on hydrological regimes in Europe: a continental perspective. Glob. Environ. Change 9, 5–23 (1999).

    Article  Google Scholar 

  10. Harrison, P. A. & Butterfield, R. E. Effects of climate change on Europe-wide winter wheat and sunflower productivity. Clim. Res. 7, 225–241 (1996).

    Article  Google Scholar 

  11. Carter, T. R., Parry, M. L., Harasawa, H. & Nishioka, S. IPCC Technical Guidelines for Assessing Climate Change Impacts and Adaptations(UCL/CGER, London/Tsukuba, (1994).

    Google Scholar 

  12. Parry, M. L. & Carter, T. Climate Impact and Adaptation Assessment(Earthscan, London, (1998).

    Google Scholar 

  13. Hope, C., Anderson, J. & Wenman, P. Policy analysis of the greenhouse effect. Energy Policy 21, 327–338 (1993).

    Article  Google Scholar 

  14. Nordhaus, W. D. Optimal greenhouse gas reductions & tax policy in the ’DICE’ model. Am. Econ. Rev. Pap. Proc. 83, 313–317 (1993).

    Google Scholar 

  15. Fankhauser, S. Valuing Climate Change(Earthscan, London, (1995).

    Google Scholar 

  16. Tol, R. S. J. The damage costs of climate change: toward more comprehensive calculations. Environ. Resource Econ. 5, 353–374 (1995).

    Article  Google Scholar 

  17. Mitchell, J. F. B., Johns, T. C., Eagles, M., Ingram, W. J. & Davis, R. A. Towards the construction of climate change scenarios. Clim. Change(in the press).

  18. Hulme, M. et al. Construction of a 1961–90 climatology for Europe for climate change impacts and modelling applications. Int. J. Climatol. 15, 1333–1363 (1995).

    Article  Google Scholar 

  19. Wilby, R. & Wigley, T. M. L. Downscaling general circulation model output: a review of methods and limitations. Prog. Phys. Geogr. 21, 530–548 (1997).

    Article  Google Scholar 

  20. Richie, J. & Otter, S. in ARS Wheat Yield Project(ed.Willis, W. O.) 159–175 (Dept of Agriculture, Agriculture Research Service, ARS-38, Washington DC, (1985).

    Google Scholar 

  21. Godwin, D., Ritchie, J., Singh, U. & Hunt, L. A User's Guide to CERES-Wheat - V2.10(Simulation manual IFDC-SM-2, Int. Fertilizer Development Center, Muscle Shoals, AL, (1990).

    Google Scholar 

  22. Weir, A. H., Bragg, P. L., Porter, J. R. & Rayner, J. H. Awinter wheat crop simulation model without water or nutrient limitations. J. Agric. Sci. 102, 371–382 (1984).

    Article  Google Scholar 

  23. Porter, J. R. AFRCWHEAT2: a model of the growth and development of wheat incorporating responses to water and nitrogen Eur. J. Agronomy 2, 69–82 (1993).

    Article  Google Scholar 

  24. Harrison, P. A. Modelling the effects of climate change on wheat productivity in Europe. Aspects Appl. Biol. 45, 41–48 (1996).

    Google Scholar 

  25. Harrison, P. A., Butterfield, R. E. & Gawith, M. J. in Climate Change and Agriculture in Europe: Assessment of Impacts and Adaptations (eds Harrison, P. A., Butterfield, R. E. & Downing, T. E.) 370–379 (Res. Rep. No. 9, Environmental Change Unit, Univ. Oxford, (1995).

    Google Scholar 

  26. Cure, J. D. & Acock, B. Crop responses to carbon dioxide doubling: a literature survey. Agric. Forest Meteorol. 38, 127–145 (1986).

    Article  ADS  Google Scholar 

  27. Kimball, B. A. et al. Productivity and water-use of winter wheat under free-air CO2enrichment. Glob. Change Biol. 1, 429–442 (1995).

    Article  ADS  Google Scholar 

  28. Batts, G. R. et al. Yield and partitioning in crops of contrasting cultivars of winter wheat in response to CO2and temperature in field studies using temperature gradient tunnels. J. Agric. Sci. 130, 17–27 (1998).

    Article  Google Scholar 

  29. Tett, S. F. B., Johns, T. C. & Mitchell, J. F. B. Global and regional variability in a coupled AOGCM. Clim. Dyn. 13, 303–323 (1997).

    Article  Google Scholar 

  30. Leggett, J., Pepper, W. J. & Swart, R. J. in Climate Change 1992: the Supplementary Report to the IPCC Scientific Assessment(eds Houghton, J. T., Callander, B. A. & Varney, S. K.) 75–95 (Cambridge Univ. Press, (1992).

    Google Scholar 

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Model data were obtained through the Climate Impacts LINK Project. This work was supported by DGXII of the Commission of the European Community.

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Correspondence to Mike Hulme.

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Hulme, M., Barrow, E., Arnell, N. et al. Relative impacts of human-induced climate change and natural climate variability. Nature 397, 688–691 (1999).

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