Consistent negative response of US crops to high temperatures in observations and crop models

Bernhard Schauberger (1) , Sotirios Archontoulis (2) , Almut Arneth (3) , Juraj Balkovic (4) , Philippe Ciais (5, 6) , Delphine Deryng (7) , Joshua Elliott (7) , Christian Folberth (8) , Nikolay Khabarov (8) , Christoph Müller (1) , Thomas A.M. Pugh (9) , Susanne Rolinski (1) , Sibyll Schaphoff (1) , Erwin Schmid (9) , Xuhui Wang (10, 11) , Wolfram Schlenker (12) , Katja Frieler (1)

1 PIK - Potsdam Institute for Climate Impact Research
2 ISU - Iowa State University
3 IMK-IFU - Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung
4 Department of Soil Science, Faculty of Natural Sciences
5 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
6 ICOS-ATC - ICOS-ATC
7 Department of Computer Science, University of Chicago
8 IIASA - International Institute for Applied Systems Analysis [Laxenburg]
9 School of Geography, Earth and Environmental Sciences and Birmingham Institute of Forest Research
10 Sino-French Institute of Earth System Science, College of Urban and Environmental Sciences
11 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
12 University of Colombia

High temperatures are detrimental to crop yields and could lead to global warming-driven reductions in agricultural productivity. To assess future threats, the majority of studies used process-based crop models, but their ability to represent effects of high temperature has been questioned. Here we show that an ensemble of nine crop models reproduces the observed average temperature responses of US maize, soybean and wheat yields. Each day $>$30 °C diminishes maize and soybean yields by up to 6% under rainfed conditions. Declines observed in irrigated areas, or simulated assuming full irrigation, are weak. This supports the hypothesis that water stress induced by high temperatures causes the decline. For wheat a negative response to high temperature is neither observed nor simulated under historical conditions, since critical temperatures are rarely exceeded during the growing season. In the future, yields are modelled to decline for all three crops at temperatures $>$30 °C. Elevated CO$_2$ can only weakly reduce these yield losses, in contrast to irrigation.

Domaines: Climatologie; Sciences de la Terre

Bernhard Schauberger, Sotirios Archontoulis, Almut Arneth, Juraj Balkovic, Philippe Ciais, et al.. Consistent negative response of US crops to high temperatures in observations and crop models. Nature Communications, 2017, 8, pp.13931. ⟨10.1038/ncomms13931⟩. ⟨cea-02138193⟩