A novel city-level carbon emission quota allocation method for carbon peak and neutrality targets

To accomplish the dual targets of carbon peak and neutrality, China has introduced an emissions trading scheme as a leading mitigation instrument, with carbon emission quota allocation as the top key design. Different from previous studies mostly at the national or provincial level, this paper develops a novel city-level allocation method for carbon emission quotas. In particular, three major steps are taken in this method. First, this paper establishes the most detailed and latest long-term database of carbon emissions for cities via both bottom-up and top-down approaches in 2005–2020, and elucidates the spatiotemporal distribution characteristics using cities in Guangdong Province as a case study. Second, this paper proposes a hybrid method based on the fairness and efficiency principles by integrating the multi-index method and zero-sum gains slacks-based measure to allocate the carbon emission quotas in 2030. Third, this paper constructs a comprehensive evaluation to verify the superiority of the proposed method from the perspectives of fairness, efficiency, and cost. According to the method, the cities in the Pearl River Delta region, which have higher gross domestic product and larger population and emissions, obtain large share of emission quotas (more than 70%), while those in less developed regions such as Northern Guangdong with the lowest population and emissions have small share of emission quotas (less than 10%). The results highlight the importance of tailored carbon emission quotas for different cities.