Impacts of biofuel cultivation on mortality and crop yields
Impacts of biofuel cultivation on mortality and crop yields
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DOI：
10.1038/nclimate1788
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发表时间：
2013-05-01
影响因子：
30.7
通讯作者：
Hewitt, C. N.
中科院分区：
文献类型：
--
作者：
Ashworth, K.;Wild, O.;Hewitt, C. N.
地面臭氧是一种重要的空气污染物，每年在欧洲造成约 22,000 人死亡(1)、农作物产量大幅下降(2) 和生物多样性丧失(3)。它是在对流层中通过涉及氮氧化物 (NOx) 和挥发性有机化合物 (VOC) 的光化学反应产生的。生物圈是 VOC 的主要来源，估计全球植被每年释放 1,150 TgC(-1)（相当于 VOC 排放总量的 90%）(4)。就质量（约 500 TgC yr(-1)）和化学反应性 (4) 而言，异戊二烯（2-甲基-1,3-丁二烯）是最重要的生物 VOC，并且在调节地面臭氧浓度 (5) 方面发挥着重要作用。对气候变化和能源安全的担忧正在推动生物能源作物生产的积极扩张，其中许多植物物种比它们正在取代的传统作物排放更多的异戊二烯。在这里，我们量化了欧洲种植 72 Mha 生物燃料作物引起的异戊二烯排放率的增加。然后，我们估计地面臭氧浓度的最终变化以及这些变化可能对人类死亡率和农作物产量造成的影响。我们的研究强调，在考虑种植生物燃料原料作物以减少温室气体排放时，需要考虑的不仅仅是简单的碳预算。
Ground-level ozone is a priority air pollutant, causing similar to 22,000 excess deaths per year in Europe(1), significant reductions in crop yields(2) and loss of biodiversity(3). It is produced in the troposphere through photochemical reactions involving oxides of nitrogen (NOx) and volatile organic compounds (VOCs). The biosphere is the main source of VOCs, with an estimated 1,150 TgC yr(-1) (similar to 90% of total VOC emissions) released from vegetation globally(4). Isoprene (2-methyl-1,3-butadiene) is the most significant biogenic VOC in terms of mass (around 500 TgC yr(-1)) and chemical reactivity(4) and plays an important role in the mediation of ground-level ozone concentrations(5). Concerns about climate change and energy security are driving an aggressive expansion of bioenergy crop production and many of these plant species emit more isoprene than the traditional crops they are replacing. Here we quantify the increases in isoprene emission rates caused by cultivation of 72 Mha of biofuel crops in Europe. We then estimate the resultant changes in ground-level ozone concentrations and the impacts on human mortality and crop yields that these could cause. Our study highlights the need to consider more than simple carbon budgets when considering the cultivation of biofuel feedstock crops for greenhouse-gas mitigation.