Exploring the equity in allocating carbon offsetting responsibility for international aviation

•We study the Carbon Offsetting and Reduction Scheme for International Aviation.•We compare the equity of five carbon offsetting mechanisms.•Countries may have conflicting interests in the current mechanism.•We use preference score compromise method to balance the interests of countries. This paper compares the offsetting responsibilities of countries under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) and four equity principles, that is, historical responsibility (HR), ability to pay (AP), equal per capita emissions (EP), and emissions intensity (EI). We also use the method of preference score compromise (PSC) to design a commonly acceptable compromise mechanism. We find that, first, the USA, the UAE and China will be affected most if the mechanism is changed from CORSIA to another. Second, CORSIA is a good choice for the USA, Germany, France, and Australia, while other countries with the highest revenue tonne kilometers in international aviation may have strong motivations to change from CORSIA to AP or EP. Third, EI does not bring the lowest cumulative offsetting costs for any country, but is most similar to the compounding mechanism under PSC. Finally, some policy implications are provided.