The hidden signature of temperature-moisture couplings in the heat sensitivity of global crops
- 1Columbia University, Earth and Environmental Science, Hoboken, United States of America (lesk@ldeo.columbia.edu)
- 2Department of Earth and Environmental Science, Columba University, New York, NY, USA
- 3Department of Geography and the Environment, Syracuse University, Syracuse, NY, USA
- 4Department of Geography, Dartmouth College, Hanover, NH, USA
- 5Institute on the Environment, University of Minnesota, St. Paul, MN, USA
- 6Climate and Environmental Physics, University of Bern, Bern, Switzerland
- 7Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
- 8Department of Computational Hydrosystems, Centre for Environmental Research – UFZ, Leipzig, Germany
- 9Institute for Atmospheric and Climate Science, ETH Zürich, Zürich, Switzerland
Rising air temperatures are a leading risk to global crop production and food security under climate change. Recent research has emphasized the critical role of moisture availability in regulating crop responses to heat and the importance of temperature-moisture couplings in the genesis of concurrent hot and dry conditions. Here, we demonstrate that the heat sensitivity of key global crops is dependent on the local strength of couplings between temperature and moisture in the climate system (namely, the interannual correlations of growing season temperature with evapotransipration and precipitation). Over 1970-2013, maize and soy yields declined more during hotter growing seasons where decreased precipitation and evapotranspiration more strongly accompanied higher temperatures. Based on this historical pattern and a suite of CMIP6 climate model projections, we show that changes in temperature-moisture couplings in response to warming could enhance the heat sensitivity of these crops as temperatures rise, worsening the impact of warming by ~5% on global average. However, these changes will benefit crops in some areas where couplings weaken, and are highly uncertain in others. Our results demonstrate that climate change will impact crops not only through warming, but also through changes in temperature-moisture couplings, which may alter the sensitivity of crop yields to heat as warming proceeds. Robust adaptation of cropping systems will need to consider this underappreciated risk to food production from climate change.
How to cite: Lesk, C., Coffel, E., Winter, J., Ray, D., Zscheischler, J., Seneviratne, S., and Horton, R.: The hidden signature of temperature-moisture couplings in the heat sensitivity of global crops, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1419, https://doi.org/10.5194/egusphere-egu21-1419, 2021.
