Drivers and critical supply chain paths of black carbon emission: A structural path decomposition

As the second largest factor contributing to global warming, black carbon (BC) is also the main cause of smog pollution in Chinese cities and has negative influence on residential health. In this paper, structural decomposition analysis (SDA) and structural path decomposition (SPD) are jointly used to identify the socioeconomic factors and critical supply chain paths driving consumption-based BC changes in Sichuan Province, which has become a main BC emission source since the implementation of "Western Development Strategy". The SDA results show that economic growth contributes 75.02 kt emission increase. Emission intensity plays a critical role in emission reduction, which offsets the emission increase by 56.00 kt. The results of SPD identify that the major paths influencing BC emission changes are "Petroleum Processing→(Construction/Metal Smelting and Production/Machinery and Equipment)→Final Demand," "Agriculture→(Food Production/Agriculture)→Final Demand," and "Transportation→(Commercial and Institution)→Final Demand." Socioeconomic drivers might pose a bidirectional impact on BC emission on different supply paths. The results reveal that BC reduction should emphasize reducing the emission intensity of the upstream sector, improving the production efficiency of the intermediate sector, and using cleaner alternatives in the downstream sectors on critical paths. The case of Sichuan may provide insights into the BC mitigation practices of other regions.