Fluctuations in temperature and precipitation are expected to increase with global climate change, with more frequent, more intense and longer-lasting extreme events, posing greater challenges for the security of global food production. Here we propose a generic framework to assess the impact of climate-induced crop yield risk under both current and future scenarios by combining a stochastic model for synthetic climate generation with a well-validated statistical crop yield model. The synthetic climate patterns were generated using the extended Empirical Orthogonal Function method based on historically observed and projected climate conditions. We applied our framework to assess the corn and soybean yield risk in the U.S. Midwest for historical and future climate conditions. We found that: (1) in the U.S. Midwest, about 45 % and 40 % of the interannual variability in corn and soybean yield, respectively, can be explained by the climate; (2) the risk level is higher in the southwest and northwest regions of the U.S. Midwest corresponding to 25 % yield reduction for both corn and soybean compared to other regions; (3) the severity for the 1988 and 2012 major droughts quantified by our method represent 21-year and 30-year events for corn, and 7-year and 12-year events for soybean, respectively; (4) the crop yield risk will increase under a future climate scenario (i.e., Representative Concentration Pathway 8.5 or RCP8.5 at 2050) compared with the current climate condition, with averaged yield decreases and yield variability increases for both corn and soybean. The framework and the results of this study enable applications for risk management policies and practices for the agriculture sectors.

随着全球气候变化，气温和降水的波动预计将加大，极端事件发生频率更高、强度更大、持续时间更长，对全球粮食生产安全构成更大挑战。在这里，我们提出了一个通用框架，通过将合成气候生成的随机模型与经过充分验证的统计作物产量模型相结合，评估当前和未来情景下气候引起的作物产量风险的影响。综合气候模式是使用基于历史观测和预测气候条件的扩展经验正交函数方法生成的。我们应用我们的框架来评估美国中西部历史和未来气候条件下的玉米和大豆产量风险。我们发现：（1）在美国中西部，气候可以解释玉米和大豆产量的年际变化分别约 45% 和 40%；(2) 美国中西部西南和西北地区的风险水平较高，与其他地区相比，玉米和大豆的减产幅度为 25%；(3) 用我们的方法量化的 1988 年和 2012 年主要干旱的严重程度分别代表玉米的 21 年和 30 年事件，以及大豆的 7 年和 12 年事件；(4) 与当前气候条件相比，在未来气候情景下（即 2050 年代表性浓度路径 8.5 或 RCP8.5）作物产量风险将增加，玉米和大豆的平均产量下降和产量变异性增加。