Regional Disparities in the Beneficial Effects of Rising CO2 Concentrations on Crop Water Productivity

Research output: Contribution to journalArticlepeer-review

Authors

  • Delphine Deryng
  • Joshua Elliott
  • Christian Folberth
  • Christoph Mueller
  • Kenneth Boote
  • Declan Conway
  • Alex Ruane
  • Dieter Gerten
  • James Jones
  • Nikolay Khabarov
  • Stefan Olin
  • Sibyll Schaphoff
  • Erwin Schmid
  • Hong Yang
  • Cynthia Rosenzweig

Colleges, School and Institutes

External organisations

  • Univ E Anglia
  • University of Chicago
  • Swiss Federal Institute of Aquatic Science and Technology (EAWAG), 8600 Duebendorf, Switzerland
  • International Institute for Applied Systems Analysis
  • Potsdam Institute for Climate Impact Research
  • Karlsruhe Institute of Technology

Abstract

Rising atmospheric CO2 concentrations [CO2] are expected to enhance photosynthesis and reduce crop water use1. However, there is high uncertainty about the global implications of these effects for future crop production and agricultural water requirements under climate change. Here we combine results from networks of field experiments1,2 and global crop models3 to present a spatially explicit global perspective on crop water productivity (CWP, the ratio of crop yield to evapotranspiration) for wheat, maize, rice and soybean under elevated [CO2] and associated climate change projected for a high-end greenhouse gas emissions scenario. We find CO2 effects increase global CWP by 10[0;47]%–27[7;37]% (median[interquartile range] across the model ensemble) by the 2080s depending on crop types, with particularly large increases in arid regions (by up to 48[25;56]% for rainfed wheat). If realized in the fields, the eects of elevated [CO2] could considerably mitigate global yield losses whilst reducing agricultural consumptive water use (4–17%). We identify regional disparities driven by dierences in growing conditions across agro-ecosystems that could have implications for increasing food production without compromising water security. Finally, our results demonstrate the need to expand field experiments and encourage greater consistency in modelling the effects of rising [CO2] across crop and hydrological modelling communities.

Details

Original languageEnglish
Pages (from-to)786–790
JournalNature Climate Change
Volume6
Early online date18 Apr 2016
Publication statusPublished - 2016