Diffenbaugh Noah S, Hertel Thomas W, Scherer Martin, Verma Monika
Department of Environmental Earth System Science and Woods Institute for the Environment, Stanford University, CA, USA ; Department of Earth and Atmospheric Sciences, Purdue University, IN, USA ; Purdue Climate Change Research Center, Purdue University, IN, USA.
Nat Clim Chang. 2012 Jul 1;2:514-518. doi: 10.1038/nclimate1491. Epub 2012 Apr 22.
Recent price spikes(1,2) have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades(3,4). However, commodity price volatility is also influenced by other factors(5,6), which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change.
近期价格飙升(1,2)引发了人们的担忧,即气候变化可能在未来几十年降低谷物产量,从而加剧粮食不安全状况(3,4)。然而,大宗商品价格波动也受到其他因素的影响(5,6),这些因素可能会加剧或缓冲气候变化的影响。我们在此表明,美国玉米价格波动对近期气候变化的敏感度高于对能源政策影响或农业与能源市场整合的敏感度,并且生物燃料指令的存在使对气候变化的敏感度提高了50%以上。气候变化的影响主要是由美国主要玉米种植区严重高温天气的加剧所驱动的,这导致美国玉米价格波动随着未来三十年预计的全球变暖而急剧增加。农业与能源市场的更紧密整合会缓和气候变化的影响,除非生物燃料指令具有约束力,在这种情况下玉米价格波动反而会加剧。然而,尽管对美国玉米价格波动有重大影响,但我们发现对食品价格的影响相对较小。我们的研究结果凸显了能源政策、能源与农业联系以及气候变化之间相互作用的至关重要性。