Fair effort-sharing for climate change mitigation: a normative approach

A major challenge in climate change negotiations lies in devising an effort-sharing method perceived as fair by most, if not all, governments. The United Nations Framework Convention on Climate Change emphasizes two core fairness principles for sharing mitigation efforts: common but differentiated responsibilities, which holds that nations with higher greenhouse gas emissions should contribute more, and respective capabilities, which asserts that economically advantaged countries should bear a greater share of the burden. These principles, while compelling, often conflict in practice. This paper introduces and axiomatically characterizes a family of effort-sharing methods designed to balance these competing principles. The proposed methods are computationally efficient and their practical relevance is demonstrated using global data.