2021-09-30-全球发展中心-评估气候负债_计算各国因碳排放而遭受的历史损害的成本_为未来气候融资承诺提供信息（英）_58页_9mb

Executive Summary

This paper proposes a method for calculating financial climate liabilities based on historical CO2 emissions, using the concept of externalities. A carbon cost is applied to emissions, accounting for the social cost of carbon and adjusting for the timing of emissions since a liability cut-off point in 1979. The main scenario estimates a global carbon liability of $34 trillion at $4,459 per capita, with OECD countries accounting for about $190 billion in annual liability payments. This suggests that even under conservative assumptions, historical emissions impose a significant financial burden, justifying higher climate finance commitments beyond the $100 billion/year pledged by developed countries.

Key goals of this approach are to inform future climate finance commitments, address historical responsibilities, and promote equitable contributions from all nations. Alternative scenarios, including variations in carbon costs and discount rates, show that liabilities can range from $7.2 trillion to $63.4 trillion globally, highlighting sensitivity to assumptions. Notably, this model assigns liabilities to both developed and developing countries like China, implying that OECD countries and major emitters should contribute more to post-2025 climate finance goals.

The methodology involves calculating liabilities based on cumulative emissions, discounting historical costs, and a terminology analysis of UN General Assembly records to determine when societal awareness of climate damage existed. Results emphasize that later emissions were more damaging due to higher marginal costs, leading to a concentration of liability in certain groups. This framework supports fair climate finance negotiations by quantifying historical damage costs and encouraging policymakers to consider comprehensive approaches to climate liability.