Stronger temperature-moisture couplings exacerbate the impact of climate warming on global crop yields
Stronger temperature-moisture couplings exacerbate the impact of climate warming on global crop yields
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DOI：
10.1038/s43016-021-00341-6
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发表时间：
2021-09-01
期刊：
影响因子：
23.2
通讯作者：
Horton, Radley
中科院分区：
文献类型：
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作者：
Lesk, Corey;Coffel, Ethan;Horton, Radley
炎热和干燥的条件相结合，通过高温和干旱胁迫降低了作物产量。作物的热敏感性取决于温度和湿度之间耦合的局部强度，但未来气候将如何影响温度-水分耦合尚不清楚。基于历史模式和一套气候模型，这项研究预测，气候变化将改变这种耦合，并可能加剧变暖对世界上一些最重要的作物的影响。气温上升是全球农作物生产的主要风险。最近的研究强调了水分有效性在调节作物对热的反应方面的关键作用，以及温度-水分耦合在驱动同时发生的高温和干旱方面的重要性。在这里，我们论证了全球主要农作物的热敏感性取决于气候系统中温度和水分之间耦合的局部强度。在1970-2013年间，玉米和大豆产量在较热的生长季节下降得更多，这些地区的降雨量和蒸散量减少与较高的气温相伴而来，这表明高温和干旱对作物的复合影响。基于这一历史模式和一系列气候模型预测，我们表明，随着气温的上升，温度-水汽耦合的变化可能会增强这些作物的热敏感性，使全球平均气候变暖的影响恶化-5%(在气候模型中为-17%至11%)。然而，这些变化将有利于耦合减弱的作物，包括亚洲大部分地区，而且一些地区预计的影响高度不确定。我们的结果表明，气候变化不仅会通过变暖来影响作物，还会通过改变热-湿复合胁迫的驱动因素来影响作物，这可能会随着变暖的进行而改变作物产量对热的敏感性。种植制度的稳健适应将需要考虑到气候变化对粮食生产的这种未被认识到的风险。
The combination of hot and dry conditions reduces crop yields through heat and drought stresses. The heat sensitivity of crops depends on the local strength of couplings between temperature and moisture, but how future climate will impact the temperature-moisture couplings remains unknown. On the basis of historical patterns and a suite of climate models, this study projects that climate change will modify the couplings and probably worsen the impacts of warming on some of the world's most important crops.Rising air temperatures are a leading risk to global crop production. Recent research has emphasized the critical role of moisture availability in regulating crop responses to heat and the importance of temperature-moisture couplings in driving concurrent heat and drought. Here, we demonstrate that the heat sensitivity of key global crops depends on the local strength of couplings between temperature and moisture in the climate system. Over 1970-2013, maize and soy yields dropped more during hotter growing seasons in places where decreased precipitation and evapotranspiration more strongly accompanied higher temperatures, suggestive of compound heat-drought impacts on crops. On the basis of this historical pattern and a suite of climate model projections, we show that changes in temperature-moisture couplings in response to warming could enhance the heat sensitivity of these crops as temperatures rise, worsening the impact of warming by -5% (-17 to 11% across climate models) on global average. However, these changes will benefit crops where couplings weaken, including much of Asia, and projected impacts are highly uncertain in some regions. Our results demonstrate that climate change will impact crops not only through warming but also through changing drivers of compound heat-moisture stresses, which may alter the sensitivity of crop yields to heat as warming proceeds. Robust adaptation of cropping systems will need to consider this underappreciated risk to food production from climate change.