ABSTRACT: Adaptation will be essential in many sectors, including agriculture, as a certain level of warming is anticipated even after substantial climate mitigation. However, global adaptation costs and adaptation limits in agriculture are understudied. Here, we estimate the global adaptation cost and residual damage (climate change impacts after adaptation) for maize, rice, wheat and soybean using a global gridded crop model and empirical production cost models. Producers require additional expenditures under climate change to produce the same crop yields that would be achieved without climate change, and this difference is defined as the adaptation cost. On a decadal mean basis, the undiscounted global cost of climate change (adaptation cost plus residual damage) for the crops are projected to increase with warming from US$63 billion (B) at 1.5°C to $80 B at 2°C and to $128 B at 3°C per year. The adaptation cost gradually increases in absolute terms, but the share decreases from 84% of the cost of climate change ($53 B) at 1.5°C to 76% ($61 B) at 2°C and to 61% ($8 B) at 3°C. The residual damage increases from 16% ($10 B) at 1.5°C to 24% ($19 B) at 2°C and to 39% ($50 B) at 3°C. Once maintaining yields becomes difficult due to the biological limits of crops or decreased profitability, producers can no longer bear adaptation costs, and residual damages increase. Our estimates offer a basis to identify the gap between global adaptation needs and the funds available for adaptation.

中文翻译：

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气候变化适应成本和对全球农作物产量的残留损害

摘要：在包括农业在内的许多部门中，适应都将是至关重要的，因为即使在大幅缓解气候变化之后，也有望达到一定程度的变暖。但是，对全球适应成本和农业适应限制的研究不足。在这里，我们使用全球网格化作物模型和经验生产成本模型估算了玉米，水稻，小麦和大豆的全球适应成本和残留损害（适应后的气候变化影响）。生产者需要在气候变化下增加支出，才能生产出与没有气候变化就能达到的相同的作物产量，这种差异被定义为适应成本。以十年平均数为基础，预计随着气候变暖，全球气候变化的未补偿成本（适应成本加上残留损害）将从630亿美元（B）上升至1。每年从5°C到2°C为80B，在3°C为128B。适应成本的绝对值逐渐增加，但所占份额从1.5°C时的气候变化成本（84 B）的84％降至2°C时的76％（$ 61 B）和62％的61％（$ 8 B） 3℃。残余伤害从1.5°C时的16％（$ 10 B）增至2°C时的24％（​​$ 19 B）和3°C时的39％（$ 50 B）。一旦由于农作物的生物学限制或降低的获利能力而难以维持单产，生产者将不再承担适应成本，而残余损害也会增加。我们的估算为确定全球适应需求与适应资金之间的差距提供了基础。5°C在2°C下达到76％（$ 61 B），在3°C下达到61％（$ 8 B）。残余伤害从1.5°C时的16％（$ 10 B）增至2°C时的24％（​​$ 19 B）和3°C时的39％（$ 50 B）。一旦由于农作物的生物学限制或降低的获利能力而难以维持产量，生产者将不再承担适应成本，并且残余损害也会增加。我们的估算为确定全球适应需求与适应资金之间的差距提供了基础。5°C在2°C下达到76％（$ 61 B），在3°C下达到61％（$ 8 B）。残余伤害从1.5°C时的16％（$ 10 B）增至2°C时的24％（​​$ 19 B）和3°C时的39％（$ 50 B）。一旦由于农作物的生物学限制或降低的获利能力而难以维持产量，生产者将不再承担适应成本，并且残余损害也会增加。我们的估算为确定全球适应需求与适应资金之间的差距提供了基础。