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. 2017 Aug 29;114(35):9326-9331.
doi: 10.1073/pnas.1701762114. Epub 2017 Aug 15.

Temperature increase reduces global yields of major crops in four independent estimates

Chuang Zhao  1 , Bing Liu  2   3   4   5   6 , Shilong Piao  7   8   9 , Xuhui Wang  1 , David B Lobell  10 , Yao Huang  11 , Mengtian Huang  1 , Yitong Yao  1 , Simona Bassu  12 , Philippe Ciais  13 , Jean-Louis Durand  14 , Joshua Elliott  15   16 , Frank Ewert  17   18 , Ivan A Janssens  19 , Tao Li  20 , Erda Lin  21 , Qiang Liu  1 , Pierre Martre  22 , Christoph Müller  23 , Shushi Peng  1 , Josep Peñuelas  24   25 , Alex C Ruane  26   16 , Daniel Wallach  27 , Tao Wang  8   9 , Donghai Wu  1 , Zhuo Liu  1 , Yan Zhu  2   3   4   5 , Zaichun Zhu  1 , Senthold Asseng  28
Affiliations

Temperature increase reduces global yields of major crops in four independent estimates

Chuang Zhao et al. Proc Natl Acad Sci U S A. .

Abstract

Wheat, rice, maize, and soybean provide two-thirds of human caloric intake. Assessing the impact of global temperature increase on production of these crops is therefore critical to maintaining global food supply, but different studies have yielded different results. Here, we investigated the impacts of temperature on yields of the four crops by compiling extensive published results from four analytical methods: global grid-based and local point-based models, statistical regressions, and field-warming experiments. Results from the different methods consistently showed negative temperature impacts on crop yield at the global scale, generally underpinned by similar impacts at country and site scales. Without CO2 fertilization, effective adaptation, and genetic improvement, each degree-Celsius increase in global mean temperature would, on average, reduce global yields of wheat by 6.0%, rice by 3.2%, maize by 7.4%, and soybean by 3.1%. Results are highly heterogeneous across crops and geographical areas, with some positive impact estimates. Multimethod analyses improved the confidence in assessments of future climate impacts on global major crops and suggest crop- and region-specific adaptation strategies to ensure food security for an increasing world population.

Keywords: climate change impact; global food security; major food crops; temperature increase; yield.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Mean annual temperature changes over time. (A) Historically observed temperature anomalies relative to 1961–1990 for global growing areas of four individual crops. (B) Future projected temperature changes (2071–2100 in comparison with 1981–2010 baseline) of four crop-growing areas and the globe (land and sea surface) under four representative concentration pathway (RCP) scenarios of increasing greenhouse gas concentrations. Error bars represent SDs in the climate model results.
Fig. 2.
Fig. 2.
Multimethod estimates of global crop yield changes in response to temperature increase. (A) Impacts on crop yields of a 1 °C increase in global temperature in grid-based simulations (Grid-Sim), point-based simulations (Point-Sim), field-warming experiments (Point-Obs), and statistical regressions at the country level (Regres_A) (9) and the global level (Regres_B) (8). Circles, means of estimates from each method or medians for Grid- and Point-Sim. Filled bars, means of the multimethod ensemble. Error bars show 95% CIs for individual methods (gray lines) and the ensemble of methods (black lines). (B) Projected changes in yield due to temperature changes by the end of the 21st century. CIs of 95% are given in square brackets.
Fig. 3.
Fig. 3.
Multimethod estimates of grain yield changes with a 1 °C increase in global temperature for the five major countries producing each crop. (A) Wheat. (B) Rice. (C) Maize. (D) Soybean. Grid-Sim, Point-Sim, Point-Obs, and Regres_A are grid-based simulations, point-based simulations, field-warming experiments, and statistical regressions at the country level (Regres_A) (9), respectively. Regres_C is another regression method used at the country scale (13). Regres_D–K represents various country-level regression analyses used for specific crops or countries shown by individual labels D–K above the bars. Vertical axes show the temperature impact on crop yield in percent per degree Celsius increase. Error bars are 95% CIs. Values for error margins are not available for point-based observations for maize in China.
Fig. 4.
Fig. 4.
Site-based multimethod ensemble of crop yield changes with 1 °C of global temperature increase. Site estimates from more than three methods are shown for wheat (A), rice (B), and maize (C) or from two methods for soybean (D). Grid-Sim, Point-Sim, and Point-Obs are grid-based simulations, point-based simulations, and field-warming experiments, respectively. Regres_L–N are site-, county- or city-scale regression analyses for specific crops shown by labels L–N next to the mean of the plotted dataset. Error bars are 95% CIs. Error bars for the Jinzhou (China) results for regression L and N were not available.
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References

    1. Rosenzweig C, et al. Assessing agricultural risks of climate change in the 21st century in a global gridded crop model intercomparison. Proc Natl Acad Sci USA. 2014;111:3268–3273. - PMC - PubMed
    1. Wheeler T, von Braun J. Climate change impacts on global food security. Science. 2013;341:508–513. - PubMed
    1. Porter JR, Gawith M. Temperatures and the growth and development of wheat: A review. Eur J Agron. 1999;10:23–36.
    1. Ottman MJ, Kimball BA, White JW, Wall GW. Wheat growth response to increased temperature from varied planting dates and supplemental infrared heating. Agron J. 2012;104:7–16.
    1. Nelson GC, et al. 2010. Food Security, Farming, and Climate Change to 2050: Scenarios, Results, Policy Options, IFPRI Research Monograph (International Food Policy Research Institute, Washington, DC)

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