Determining climate effects on US total agricultural productivity
Determining climate effects on US total agricultural productivity
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DOI：
10.1073/pnas.1615922114
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发表时间：
2017-03-21
影响因子：
11.1
通讯作者：
Kennedy, Jennifer A.
中科院分区：
文献类型：
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作者：
Liang, Xin-Zhong;Wu, You;Kennedy, Jennifer A.
农业生产力对气候的敏感性尚未得到充分量化。美国农业经济的全要素生产率（TFP）在过去的半个多世纪里持续增长，其中大部分增长通常归因于技术进步。许多研究已经审查了当地气候对作物产量和经济回报等部分生产力指标的影响，但这些指标不能说明国家一级的影响。量化全要素生产率和气候之间的关系对于理解美国目前的农业生产率增长是否会持续到未来至关重要。我们分析了区域气候变化和国家全要素生产率变化之间的相关性，确定了关键的气候指标，并建立了一个多变量回归模型，预测农业全要素生产率的增长，其基础上的物理理解与气候的历史关系。我们发现，不同农业地区和季节的温度和降水解释了1981-2010年TFP增长的70%的变化。迄今为止，这些区域气候趋势对全要素生产率的总体影响已经被技术进步所抵消。然而，如果这些关系继续下去，预计的气候变化可能会导致TFP平均每年下降2.84%至4.34%，在中高排放情景下。因此，即使考虑到目前的创新率，到2050年，全要素生产率也可能下降到1980年以前的水平。我们的分析通过将区域气候效应与国家经济成果联系起来，为综合评估提供了经验基础，为政策制定提供了更客观的资源。
The sensitivity of agricultural productivity to climate has not been sufficiently quantified. The total factor productivity (TFP) of the US agricultural economy has grown continuously for over half a century, with most of the growth typically attributed to technical change. Many studies have examined the effects of local climate on partial productivity measures such as crop yields and economic returns, but these measures cannot account for national-level impacts. Quantifying the relationships between TFP and climate is critical to understanding whether current US agricultural productivity growth will continue into the future. We analyze correlations between regional climate variations and national TFP changes, identify key climate indices, and build a multivariate regression model predicting the growth of agricultural TFP based on a physical understanding of its historical relationship with climate. We show that temperature and precipitation in distinct agricultural regions and seasons explain similar to 70% of variations in TFP growth during 1981-2010. To date, the aggregate effects of these regional climate trends on TFP have been outweighed by improvements in technology. Should these relationships continue, however, the projected climate changes could cause TFP to drop by an average 2.84 to 4.34% per year under medium to high emissions scenarios. As a result, TFP could fall to pre-1980 levels by 2050 even when accounting for present rates of innovation. Our analysis provides an empirical foundation for integrated assessment by linking regional climate effects to national economic outcomes, offering a more objective resource for policy making.