Center for Applied Research and Environmental Systems, University of Missouri, Columbia, MO, USA.
Environ Manage. 2010 Mar;45(3):577-89. doi: 10.1007/s00267-010-9427-0. Epub 2010 Jan 28.
Potential economic impacts of future climate change on crop enterprise net returns and annual net farm income (NFI) are evaluated for small and large representative farms in Flathead Valley in Northwest Montana. Crop enterprise net returns and NFI in an historical climate period (1960-2005) and future climate period (2006-2050) are compared when agricultural production systems (APSs) are adapted to future climate change. Climate conditions in the future climate period are based on the A1B, B1, and A2 CO(2) emission scenarios from the Intergovernmental Panel on Climate Change Fourth Assessment Report. Steps in the evaluation include: (1) specifying crop enterprises and APSs (i.e., combinations of crop enterprises) in consultation with locals producers; (2) simulating crop yields for two soils, crop prices, crop enterprises costs, and NFIs for APSs; (3) determining the dominant APS in the historical and future climate periods in terms of NFI; and (4) determining whether NFI for the dominant APS in the historical climate period is superior to NFI for the dominant APS in the future climate period. Crop yields are simulated using the Environmental/Policy Integrated Climate (EPIC) model and dominance comparisons for NFI are based on the stochastic efficiency with respect to a function (SERF) criterion. Probability distributions that best fit the EPIC-simulated crop yields are used to simulate 100 values for crop yields for the two soils in the historical and future climate periods. Best-fitting probability distributions for historical inflation-adjusted crop prices and specified triangular probability distributions for crop enterprise costs are used to simulate 100 values for crop prices and crop enterprise costs. Averaged over all crop enterprises, farm sizes, and soil types, simulated net return per ha averaged over all crop enterprises decreased 24% and simulated mean NFI for APSs decreased 57% between the historical and future climate periods. Although adapting APSs to future climate change is advantageous (i.e., NFI with adaptation is superior to NFI without adaptation based on SERF), in six of the nine cases in which adaptation is advantageous, NFI with adaptation in the future climate period is inferior to NFI in the historical climate period. Therefore, adaptation of APSs to future climate change in Flathead Valley is insufficient to offset the adverse impacts on NFI of such change.
在蒙大拿州西北弗拉特黑德谷的小农场和大农场,评估了未来气候变化对作物企业净收益和年度净农场收入(NFI)的潜在经济影响。将农业生产系统(APS)适应未来气候变化时,比较了历史气候时期(1960-2005 年)和未来气候时期(2006-2050 年)的作物企业净收益和 NFI。未来气候时期的气候条件基于政府间气候变化专门委员会第四次评估报告的 A1B、B1 和 A2 CO2 排放情景。评估步骤包括:(1)与当地生产者协商确定作物企业和 APS(即作物企业的组合);(2)模拟两种土壤的作物产量、作物价格、作物企业成本和 APS 的 NFI;(3)根据 NFI 确定历史和未来气候时期的主导 APS;(4)确定历史气候时期主导 APS 的 NFI 是否优于未来气候时期主导 APS 的 NFI。使用环境/政策综合气候(EPIC)模型模拟作物产量,根据相对于函数的随机效率(SERF)标准进行 NFI 主导地位比较。使用最适合 EPIC 模拟作物产量的概率分布来模拟两种土壤在历史和未来气候时期的 100 个作物产量值。使用历史通胀调整后的作物价格的最佳拟合概率分布和指定的作物企业成本三角概率分布来模拟 100 个作物价格和作物企业成本值。在所有作物企业、农场规模和土壤类型的平均值上,所有作物企业的平均每公顷模拟净收益下降了 24%,而 APS 的平均模拟 NFI 在历史和未来气候时期下降了 57%。尽管适应未来气候变化的 APS 是有利的(即基于 SERF,适应的 NFI 优于无适应的 NFI),但在有利的九种情况中的六种情况下,未来气候时期的适应的 NFI 劣于历史气候时期的 NFI。因此,在 Flathead Valley,适应未来气候变化的 APS 不足以抵消这种变化对 NFI 的不利影响。