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Stefan Olin

Postdoctoral fellow

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Regional disparities in the beneficial effects of rising CO2 concentrations on crop water productivity

Author

  • Delphine Deryng
  • Joshua Elliott
  • Christian Folberth
  • Christoph Müller
  • Thomas A M Pugh
  • Kenneth J. Boote
  • Declan Conway
  • Alex C. Ruane
  • Dieter Gerten
  • James W. Jones
  • Nikolay Khabarov
  • Stefan Olin
  • Sibyll Schaphoff
  • Erwin Schmid
  • Hong Yang
  • Cynthia Rosenzweig

Summary, in English

Rising atmospheric CO2 concentrations ([CO2 ]) are expected to enhance photosynthesis and reduce crop water use. 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 experiments and global crop models 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 effects of elevated [CO2 ] could considerably mitigate global yield losses whilst reducing agricultural consumptive water use (4-17%). We identify regional disparities driven by differences 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.

Department/s

  • Dept of Physical Geography and Ecosystem Science
  • MERGE - ModElling the Regional and Global Earth system
  • BECC - Biodiversity and Ecosystem services in a Changing Climate

Publishing year

2016-08-01

Language

English

Pages

786-790

Publication/Series

Nature Climate Change

Volume

6

Issue

8

Document type

Journal article

Publisher

Nature Research

Topic

  • Climate Research

Status

Published

ISBN/ISSN/Other

  • ISSN: 1758-678X