Russell Alyssa R, van Kooten G Cornelis, Izett Jonathan G, Eiswerth Mark E
Vancouver School of Economics, University of British Columbia, Vancouver, BC, Canada.
Department of Economics, University of Victoria, Victoria, BC, Canada.
Environ Manage. 2022 May;69(5):919-936. doi: 10.1007/s00267-022-01608-9. Epub 2022 Feb 19.
Mitigating the effects of human-induced climate change requires the reduction of greenhouse gases. Policymakers must balance the need for mitigation with the need to sustain and develop the economy. To make informed decisions regarding mitigation strategies, policymakers rely on estimates of the social cost of carbon (SCC), which represents the marginal damage from increased emissions; the SCC must be greater than the marginal abatement cost for mitigation to be economically desirable. To determine the SCC, damage functions translate projections of carbon and temperature into economic losses. We examine the impact that four damage functions commonly employed in the literature have on the SCC. Rather than using an economic growth model, we convert the CO pathways from the Representative Concentration Pathways (RCPs) into temperature projections using a three-layer, energy balance model and subsequently estimate damages under each RCP using the damage functions. We estimate marginal damages for 2020-2100, finding significant variability in SCC estimates between damage functions. Despite the uncertainty in choosing a specific damage function, comparing the SCC estimates to estimates of marginal abatement costs from the Shared Socioeconomic Pathways (SSPs) indicates that reducing emissions beyond RCP6.0 is economically beneficial under all scenarios. Reducing emissions beyond RCP4.5 is also likely to be economically desirable under certain damage functions and SSP scenarios. However, future work must resolve the uncertainty surrounding the form of damage function and the SSP estimates of marginal abatement costs to better estimate the economic impacts of climate change and the benefits of mitigating it.
减轻人为引起的气候变化的影响需要减少温室气体排放。政策制定者必须在减排需求与维持和发展经济的需求之间取得平衡。为了就减排策略做出明智的决策，政策制定者依赖于碳的社会成本（SCC）估计值，该值代表了排放增加带来的边际损害；为了使减排在经济上具有吸引力，SCC必须大于边际减排成本。为了确定SCC，损害函数将碳和温度的预测转化为经济损失。我们研究了文献中常用的四种损害函数对SCC的影响。我们没有使用经济增长模型，而是使用三层能量平衡模型将代表性浓度路径（RCPs）中的CO₂路径转化为温度预测，随后使用损害函数估计每个RCP下的损害。我们估计了2020年至2100年的边际损害，发现不同损害函数之间的SCC估计值存在显著差异。尽管在选择特定损害函数方面存在不确定性，但将SCC估计值与共享社会经济路径（SSPs）中的边际减排成本估计值进行比较表明，在所有情景下，将排放量减少到低于RCP6.0在经济上是有益的。在某些损害函数和SSP情景下，将排放量减少到低于RCP4.5在经济上也可能是可取的。然而，未来的工作必须解决围绕损害函数形式和边际减排成本的SSP估计值的不确定性，以便更好地估计气候变化的经济影响以及减排的好处。
