Does the low-carbon city pilot policy achieve the synergistic effect of pollution and carbon reduction?

A scientific assessment of the synergistic effect of the low-carbon city pilot policy in reducing air pollution and carbon emissions is needed to promote carbon peak and carbon neutrality. This study applied the Spatial Durbin Model-Difference in Difference technique to investigate the synergistic effect of air pollution and carbon emission reduction through the implementation of the low-carbon city pilot policy. The main results are as follows. (1) A spatial phenomenon was observed, in which there was a coexistence of urban carbon emissions and air pollution agglomerations. The spatial characteristics of the “symbiotic†carbon emissions and air pollution agglomerations were revealed. (2) The low-carbon city policy significantly reduced CO 2 , SO 2 , and PM 2.5 concentrations, and the effect of the “co-governance†of air pollution and carbon emission reduction was obvious. (3) There was a clear regional heterogeneity in the synergistic effect of air pollution and carbon emission reduction in low-carbon cities. A stronger incentive effect was apparent in central and western cities, resource-based cities, and key environmental protection cities. (4) To achieve a synergistic governance “sharing†situation, the transmission mechanism of the low-carbon city pilot policy was the reduction of total energy consumption, the promotion of industrial restructuring, the optimization of the factor endowment structure, and the continuous improvement of the urban transport structure and green innovation. Our results not only help advance the research on synergistic reduction of air pollution and carbon emissions, but also can be of interest to low-carbon city policy makers in China.