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Constraints and potentials of future irrigation water availability on agricultural production under climate change

  1. Dominik Wisserv
  1. aUniversity of Chicago Computation Institute, Chicago, IL 60637;
  2. bMath and Computer Science Division, Argonne National Laboratory, Lemont, IL 60439;
  3. cColumbia University Center for Climate Systems Research, New York, NY 10025;
  4. dTyndall Center for Climate Change Research, University of East Anglia, Norwich NR4 7TJ, United Kingdom;
  5. ePotsdam Institute for Climate Impact Research, 14473 Potsdam, Germany;
  6. fDepartment of the Geophysical Sciences, University of Chicago, Chicago, IL 60637;
  7. gCenter for Environmental Systems Research, University of Kassel, 34109 Kassel, Germany;
  8. hDepartment of Physical Geography, Utrecht University, 3584 CS, Utrecht, The Netherlands;
  9. iThe City College of New York, New York, NY 10031;
  10. jSwiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland;
  11. kUniversity of Nottingham, Nottingham NG7 2RD, United Kingdom;
  12. lNorwegian Water Resources and Energy Directorate, N-0301 Oslo, Norway;
  13. mEcosystems Services and Management Program (ESM), International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria;
  14. nWageningen University and Research Centre, 6708 PB, Wageningen, The Netherlands;
  15. oNational Institute for Environmental Studies, Tsukuba 305-8506, Japan;
  16. pLund University, 223 62 Lund, Sweden;
  17. qNational Aeronautics and Space Administration Goddard Institute for Space Studies, New York, NY 10025;
  18. rUniversity of Tokyo, Tokyo 153-8505, Japan;
  19. sUniversity of Natural Resources and Life Sciences, 1180 Vienna, Austria;
  20. tMax Planck Institute for Meteorology, 20146 Hamburg, Germany;
  21. uInstitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; and
  22. vCenter for Development Research, University of Bonn, 53113 Bonn, Germany

  1. Edited by Hans Joachim Schellnhuber, Potsdam Institute for Climate Impact Research, Potsdam, Germany, and accepted by the Editorial Board October 4, 2013 (received for review January 31, 2013)

Significance

Freshwater availability is relevant to almost all socioeconomic and environmental impacts of climate and demographic change and their implications for sustainability. We compare ensembles of water supply and demand projections driven by ensemble output from five global climate models. Our results suggest reasons for concern. Direct climate impacts to maize, soybean, wheat, and rice involve losses of 400–2,600 Pcal (8–43% of present-day total). Freshwater limitations in some heavily irrigated regions could necessitate reversion of 20–60 Mha of cropland from irrigated to rainfed management, and a further loss of 600–2,900 Pcal. Freshwater abundance in other regions could help ameliorate these losses, but substantial investment in infrastructure would be required.

Abstract

We compare ensembles of water supply and demand projections from 10 global hydrological models and six global gridded crop models. These are produced as part of the Inter-Sectoral Impacts Model Intercomparison Project, with coordination from the Agricultural Model Intercomparison and Improvement Project, and driven by outputs of general circulation models run under representative concentration pathway 8.5 as part of the Fifth Coupled Model Intercomparison Project. Models project that direct climate impacts to maize, soybean, wheat, and rice involve losses of 400–1,400 Pcal (8–24% of present-day total) when CO2 fertilization effects are accounted for or 1,400–2,600 Pcal (24–43%) otherwise. Freshwater limitations in some irrigated regions (western United States; China; and West, South, and Central Asia) could necessitate the reversion of 20–60 Mha of cropland from irrigated to rainfed management by end-of-century, and a further loss of 600–2,900 Pcal of food production. In other regions (northern/eastern United States, parts of South America, much of Europe, and South East Asia) surplus water supply could in principle support a net increase in irrigation, although substantial investments in irrigation infrastructure would be required.

Footnotes

  • ↵1To whom correspondence should be addressed. E-mail: jelliott{at}ci.uchicago.edu.

  • Author contributions: J.E., K.F., D.G., C.R., and A.C.R. designed research; J.E., D.D., C.M., M.K., D.G., M.G., M.F., Y.W., N.B., S.E., B.M.F., C.F., S.N.G., I.H., N.K., F.L., Y.M., S.O., Y.S., E.S., T.S., Q.T., and D.W. performed research; J.E., D.D., C.M., D.G., M.F., Y.W., S.E., C.F., S.N.G., I.H., N.K., F.L., Y.M., S.O., Y.S., E.S., T.S., and Q.T. contributed new analytic tools; J.E., K.F., and M.K. analyzed data; and J.E., D.D., C.M., and I.F. wrote the paper.

  • The authors declare no conflict of interest.

  • This article is a PNAS Direct Submission.

  • Data deposition: The data reported in this paper associated with the Inter-Sectoral Impact Model Intercomparison Project is hosted at http://esg.pik-potsdam.de.

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1222474110/-/DCSupplemental.

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