Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Proc Natl Acad Sci U S A. 2017 Aug 29;114(35):9326-9331. doi: 10.1073/pnas.1701762114. Epub 2017 Aug 15.
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 CO 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.
小麦、水稻、玉米和大豆提供了人类三分之二的热量摄入。因此，评估全球气温升高对这些作物生产的影响对于维持全球粮食供应至关重要，但不同的研究得出了不同的结果。在这里，我们通过综合四种分析方法（全球网格模型和局部点模型、统计回归和田间增温实验）广泛发表的结果，研究了温度对这四种作物产量的影响。不同方法的结果一致表明，在全球范围内，温度对作物产量有负面影响，这种影响在国家和地点层面上也基本一致。如果没有 CO2 施肥、有效适应和遗传改良，全球平均气温每升高 1°C，全球小麦产量平均将减少 6.0%，水稻产量减少 3.2%，玉米产量减少 7.4%，大豆产量减少 3.1%。结果在作物和地理区域之间存在高度异质性，有些结果显示有正影响。多方法分析提高了对未来气候对全球主要作物影响评估的信心，并提出了针对特定作物和地区的适应策略，以确保不断增长的世界人口的粮食安全。
