过去的130年全球升温0.85℃，未来全球气候还将持续变暖。尽管各国采取各种措施，但全球平均温度上升2℃已不可避免。中外科学家研究认为，温度每升高1℃，全球小麦产量平均降低5.7％。相关成果已发布在最新一期的气候变化领域顶尖杂志《自然—气候变化》。

南京农业大学朱艳教授介绍，目前在全球范围内定量评估温度升高对作物生产潜在效应的模型约有30种之多，而各个评估模型得出的结果存在较大差异，评估的可信度不高。如何有效提升气候变化对作物生产效应评估的可信度，科学分析全球气候变化与粮食安全生产的关系，具有极为重要的意义。

南京农业大学课题组联合国内外49家单位的科学家，在全球、国家以及站点尺度上，系统比较了不同方法在过去30年评估温度升高对小麦生产潜在效应方面的表现，提出通过综合利用不同方法形成方法集合，以提升评估的可信度。

经研究，在不考虑CO2肥效以及适应性措施情况下，温度每升高1℃，全球小麦产量平均降低4.1％—6.4％，综合三种方法评估结果的平均效应形成方法集合，得到全球小麦产量平均降低5.7％左右，95％置信区间范围为4.0％—6.9％。目前，全球小麦年产量超过7亿吨，产量下降5.7％即意味着全球每年将损失近400万吨小麦。

朱艳教授表示，该评估方法已经广泛拓展应用到水稻、玉米等其他粮食作物的评估当中。今后将着眼全国水稻和小麦主产区，更加精确量化分析气候变化对我国粮食生产的潜在效应，并关注极端天气尤其是极端高温对不同区域粮食作物生产的影响。（来源：科技日报 袁渊 张晔）

Similar estimates of temperature impacts on global wheat yield by three independent methods

Abstract  The potential impact of global temperature change on global crop yield has recently been assessed with different methods. Here we show that grid-based and point-based simulations and statistical regressions (from historic records), without deliberate adaptation or CO2 fertilization effects, produce similar estimates of temperature impact on wheat yields at global and national scales. With a 1 °C global temperature increase, global wheat yield is projected to decline between 4.1% and 6.4%. Projected relative temperature impacts from different methods were similar for major wheat-producing countries China, India, USA and France, but less so for Russia. Point-based and grid-based simulations, and to some extent the statistical regressions, were consistent in projecting that warmer regions are likely to suffer more yield loss with increasing temperature than cooler regions. By forming a multi-method ensemble, it was possible to quantify ‘method uncertainty’ in addition to model uncertainty. This significantly improves confidence in estimates of climate impacts on global food security.

原文链接：http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3115.html