Econ Papers Daily / 期刊论文
不确定性下碳定价的三个理由：简单规则的准确性
Three reasons to price carbon under uncertainty: Accuracy of simple rules
摘要
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.
中文摘要
通过扰动分析，推导出一个易于解释的最优风险调整社会碳成本规则。该规则内化了全球变暖对以下方面的不利影响：气候相关灾害反复发生的风险、不可逆级联气候临界点风险，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够较好地近似真实数值最优解，尤其是当小参数（即GDP中损害份额、灾害风险对温度的敏感性以及气候临界点风险）足够小且贴现率不太低时。若将该规则应用于具有不同供给侧结构的AK模型（例如化石燃料生产持续技术进步或多经济部门模型），其准确性依然成立。在增长调整贴现率为每年2%的情况下，社会碳成本为172美元/吨二氧化碳，其中70%源于反复发生的气候灾害，9%源于气候临界点风险。