Measurement of China's provincial social cost of carbon under the integrated socioeconomic-climate framework

The social cost of carbon is a tool for assessing the appropriateness of emission reduction measures and climate policy, and is affected by socioeconomic and climatic factors. This study aimed to explore the impact of socioeconomic factors and climate on the social cost of carbon; to this end, this study considered Chinese provinces as the focus of research. This study constructed an integrated framework for carbon emissions considering socioeconomic and climatic factors, which consisted of shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs). Subsequently, social cost of the carbon estimation model was used to calculate the social cost of carbon for China's provinces from 2022 to 2100 under different carbon emission scenarios. The results show that: under most carbon emission scenarios, provinces with a high social cost of carbon are located in the eastern developed region. For instance, Jiangsu and Guangdong had the highest values of 6.31 $/tC. Second, SSPs that are highly dependent on fossil fuels have a high social cost of carbon, which is higher than 60 $/tC in 2022 in China. The social cost of carbon under other SSPs is at a fluctuating value of 40 $/tC. Third, in terms of RCPs, the social cost of carbon for the middle baseline emission scenario (RCP6.0) is considerably lower than that for the high baseline emission scenario (RCP8.0), and the difference between them is 3.7 times that of two medium emission scenarios (RCP6.0 and RCP4.5). Fourth, there is a substantial difference between the dynamic and fixed discount rates in the social cost of carbon in the same scenario. Studying the impact of socioeconomic and climatic factors on the social cost of carbon will help in its regulation and provide a scientific basis for Chinese provinces to optimize climate policies and emission reduction measures.