PNAS：欧洲农作物产量与变化的气候

一项研究发现，自从20世纪80年代后期以来变化的气候趋势可能部分解释欧洲农作物产量的停滞。小麦和大麦的农作物产量自从20世纪90年代早期以来出现了停滞，这恰逢变暖的生长季节，但是尚不确定在农作物产量与气候之间是否存在一种因果关系。

Frances Moore 和David Lobell开发了一种统计测试，从而检测气候趋势是否影响了农作物产量。这组作者发现，自从1989年以来的温度和降水量趋势的长期变化减少了欧洲平均小麦产量的2.5%和大麦产量的3.8%。这种气候趋势还轻微地增加了欧洲大陆平均的玉米与甜菜的产量。对产量的影响在欧洲各地有广泛的差异，与平均水平相比，地中海地区的多数农作物遇到了更大的减产。

这组作者说，气候趋势造成了欧洲小麦和大麦产量停滞的10%，这提示对产量的影响的大部分可能是由于包括农业和环境政策变化在内的因素。

原文链接：The fingerprint of climate trends on European cropyields

Europe has experienced a stagnation of some crop yields since the early 1990s as well as statistically significant warming during the growing season. Although it has been argued that these two are causally connected, no previous studies have formally attributed long-term yield trends to a changing climate. Here, we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these tests to European agriculture, we find evidence that long-term temperature and precipitation trends since 1989 have reduced continent-wide wheat and barleyyields by 2.5% and 3.8%, respectively, and have slightly increased maize and sugar beet yields. These averages disguise large heterogenEity across the continent, with regions around the Mediterranean experiencing significant adverse impacts on most crops. This result means that climate trends can account for ∼10% of the stagnation in european wheat and barley yields, with likely explanations for theremainder including changes in agriculture and environmental policies.

doi: 10.1073/PNAS.1409606112

作者：Frances C. Moore