The Influence of Climate Change on Global Crop Productivity
The Influence of Climate Change on Global Crop Productivity
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DOI：
10.1104/pp.112.208298
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发表时间：
2012-12-01
期刊：
影响因子：
7.4
通讯作者：
Gourdji, Sharon M.
中科院分区：
文献类型：
--
作者：
Lobell, David B.;Gourdji, Sharon M.
过去几十年来，全球许多农业地区的气候变化趋势相当迅速，大气中二氧化碳（CO2）和臭氧（O3）水平的增加也无处不在。气候和二氧化碳在未来将继续呈上升趋势，这一事实几乎可以肯定，这提出了许多与粮食安全有关的问题，其中之一是全球农业的总生产力是否会受到影响。我们概述了这些变化影响作物产量的机制，并对气候和CO2趋势的过去和未来影响进行了估计。尽管还有许多其他与粮食安全有关的尺度和结果，但审查的重点是全球尺度的粮食生产力。在未来几十年，二氧化碳趋势可能会使全球产量每十年增加约1.8%。与此同时，如果没有有效的适应措施，变暖趋势可能会使全球产量每十年减少约1.5%，合理范围约为0%至4%。这一范围的上限是未来几十年技术和管理改进预期8%收益率的一半。目前大多数评估都没有考虑可能对产量构成挑战的许多全球变化因素，包括臭氧含量增加和降雨强度加大。未来几十年，许多因素将影响全球粮食安全，包括人口增长率、收入增长和分配、饮食偏好、疾病发生率、对其他用途（即生物能源生产、碳固存和城市发展）的土地和水资源需求增加，以及农业生产率的提高。后一个因素，我们在这里简单地定义为作物产量（即每公顷土地的粮食产量），是植物科学界特别强调的一个因素，因为研究人员和农民寻求维持与主要粮食作物的遗传学和农艺管理改进相关的令人印象深刻的历史收益。农业生产力增长的来源也是多方面的，包括公共和私人研究与发展的资金水平、土壤质量的变化、矿物肥料的供应和成本、大气中二氧化碳和臭氧（O3）的浓度以及温度（T）和降水（P）条件的变化。本次更新的重点是农业地区的天气，CO2和O3的变化，以及这些变化如何影响和影响作物生产力。在这样做的时候，我们认识到，这只是作物生产力的一部分，而作物生产力又只是未来粮食安全的一部分。例如，本《最新情况》没有提及全球变化通过农业生产力以外的途径影响粮食安全的许多方式，例如影响人类疾病发病率或收入增长率。这里的主要问题是：相对于影响生产力的许多其他因素，气候变化和二氧化碳在全球范围内影响未来作物产量方面有多重要？这一问题有助于将气候适应的挑战置于背景之下。例如，我们关心的不是影响在统计上是否与零有区别，而是这些影响的代价是否足以证明有理由大幅加速农业投资，以达到目标增长率。在讨论气候变化对粮食安全的影响时，两个空间尺度是主要关注的问题。一个是全球范围，因为人类热量的主要来源（如玉米或小麦）是国际商品，其价格由全球供需平衡决定。在这种情况下...
Climate trends over the past few decades have been fairly rapid in many agricultural regions around the world, and increases in atmospheric carbon dioxide (CO2) and ozone (O3) levels have also been ubiquitous. The virtual certainty that climate and CO2 will continue to trend in the future raises many questions related to food security, one of which is whether the aggregate productivity of global agriculture will be affected. We outline the mechanisms by which these changes affect crop yields and present estimates of past and future impacts of climate and CO2 trends. The review focuses on global scale grain productivity, notwithstanding the many other scales and outcomes of interest to food security. Over the next few decades, CO2 trends will likely increase global yields by roughly 1.8% per decade. At the same time, warming trends are likely to reduce global yields by roughly 1.5% per decade without effective adaptation, with a plausible range from roughly 0% to 4%. The upper end of this range is half of the expected 8% rate of gain from technological and management improvements over the next few decades. Many global change factors that will likely challenge yields, including higher O3 and greater rainfall intensity, are not considered in most current assessments. Many factors will shape global food security over the next few decades, including changes in rates of human population growth, income growth and distribution, dietary preferences, disease incidence, increased demand for land and water resources for other uses (ie bioenergy production, carbon sequestration, and urban development), and rates of improvement in agricultural productivity. This latter factor, which we define here simply as crop yield (ie, metric tons of grain production per hectare of land), is a particular emphasis of the plant science community, as researchers and farmers seek to sustain the impressive historical gains associated with improved genetics and agronomic management of major food crops. Sources of growth in agricultural productivity are also multifaceted and include levels of funding for public and private research and development, changes in soil quality, availability and cost of mineral fertilizers, atmospheric concentrations of CO2 and ozone (O3), and changes in temperature (T) and precipitation (P) conditions. This Update focuses on changes in weather, CO2, and O3 in agricultural areas and how that has affected and will affect crop productivity. In doing so, we recognize that this is only part of the fuller story on crop productivity, which in turn is only part of the fuller story on future food security. For example, this Update is silent on the many ways that global change can influence food security via pathways other than agricultural productivity, such as by influencing human disease incidence or income growth rates.The main question of interest here is the following: how important will climate change and CO2 be in shaping future crop yields at the global scale, relative to the many other factors that influence productivity? This question helps to set the challenge of climate adaptation in context. We are less concerned, for example, with whether impacts are statistically distinguishable from zero than with whether they are costly enough to justify a major acceleration of investment in agriculture in order to reach target growth rates. Two spatial scales are of primary interest when discussing impacts of climate change on food security. One is the global scale, because most major sources of human calories (eg maize [Zea mays] or wheat [Triticum aestivum]) are international commodities whose prices are determined by the balance of global supply and demand. In this context …