Quantitative Economics · 2026 · Ton S. van den Bremer、Christoph Hambel、Frederick van der Ploeg
中文摘要
本文利用摄动分析方法推导出一个易于解释的规则，用于确定经风险调整的最优碳社会成本。该规则将全球变暖的不利影响内部化，包括气候相关灾害反复发生的风险、不可逆的气候临界点级联风险，以及对全要素生产率的常规影响。该规则及其三个组成部分能较好地逼近真实的数值最优解，尤其是当各小参数（即损害占GDP的份额、灾害风险对温度的敏感性以及气候临界风险）足够小且贴现率不太小时。将该规则应用于具有不同供给面的AK模型（例如化石燃料生产存在持续技术进步或包含多个经济部门的情形）时，其结果同样准确。在增长率调整后贴现率为每年2%的情形下，碳社会成本为172美元/吨CO2，其中70%来自反复发生的气候灾害，9%来自气候临界风险。
Abstract
An easy‐to‐interpret rule for the optimal risk‐adjusted social cost of carbon is derived using perturbation analysis. This rule internalizes the adverse effects of global warming on the risk of recurring climate‐related disasters, the risk of irreversible cascading climate tipping points, and the usual effect on total factor productivity. It and its three components approximate the true numerical optimum well, especially if the small parameters (i.e., the share of damages in GDP, the sensitivity of the risk of disasters to temperature and the risk of climate tipping) are small enough and the discount rate is not too small. The rule is also accurate if applied to AK models with a different supply side, for example, with ongoing technical progress in fossil‐fuel production or multiple economic sectors. With a growth‐adjusted discount rate of 2%/year, the SCC is $172/tCO 2 , 70% of which is due to recurring climate disasters and 9% to climate tipping risk.