Spatiotemporal evolution of the Co-reduction of carbon emissions and air pollutants and the drivers of carbon mitigation: Evidence from a city-sector-industry perspective in China.

Existing studies have primarily focused on the co-reduction of carbon dioxide and air pollutants (CDAP) at the provincial level, in key regions, or within single sectors, while systematic analyses at the city scale, across multiple sectors, and at the disaggregated industry level remain limited. Based on all-sector data and data for four major sectors (power generation, industry, transportation, and residential use) at the city scale, together with data for 11 disaggregated industries at the provincial scale, this study applies the co-control effects coordinate system (CCECS) method and the coupling coordination degree (CCD) model to measure the level of co-reduction between carbon dioxide and major air pollutants (SO2, NOx, PM2.5 and CO). By integrating ArcGIS-based spatial analysis, LMDI decomposition, and econometric regression models, this study reveals the spatiotemporal evolution characteristics of co-reduction and the drivers of carbon mitigation. The results show that: (1) during the period 2006-2020, the overall level of co-reduction of CDAP in China increased significantly, with the spatial pattern exhibiting a diffusion trend from eastern to western regions and a gradual narrowing of inter-city disparities in coordination; (2) the CCD of the co-reduction of CDAP in the industrial, power generation, transportation, and residential sectors respectively exhibits inverted U-shaped, N-shaped, Z-shaped, and oscillatory variation patterns; and (3) the energy structure intensity effect and the energy consumption intensity effect are the primary driving factors of carbon mitigation, while the co-reduction effects of CDAP display significant heterogeneity across different sectors and industries.