Distribution dynamics, spatial differences, and convergence of synergistic pollution and carbon reduction in China

Carbon and pollution reduction are highly synergistic elements of green development, and the detailed derivation of the synergistic relationship is urgently needed. Based on the research perspective of coupling coordination, this paper firstly bases on the research perspective of coupling synergy, takes 30 provinces in China as the research object from 2011 to 2022, and constructs a coupling coordination degree model to measure the synergistic effect of pollution reduction and carbon reduction; secondly, kernel density and Dagum coefficient are used to analyze the spatial and temporal characteristics, spatial differences and sources of differences in the synergistic effects of pollution reduction and carbon reduction in China as a whole, in the three major regions and in each province; finally, the Moran index is applied to test the spatial agglomeration characteristics of the synergistic effect of pollution reduction and carbon reduction, and the spatial panel model is applied to test its β-convergence. The study shows that (1) during the study period, the level of synergistic effect on carbon reduction in China changed from good coordination to good coordination, and the synergistic effect in the western region was significantly better than that in the eastern and central regions; (2) the synergistic effect of pollution reduction and carbon reduction in China as a whole and the three regions showed obvious spatial differences, but the differences were gradually narrowing, and the supervariable density was the dominant factor of the overall differences; (3) as a whole, the synergistic effect of pollution reduction and carbon reduction among provinces has a spatial agglomeration effect, and the level of synergistic effect of pollution reduction and carbon reduction across the country and east and west regions has a significant absolute β convergence trend, while there is a significant conditional β convergence trend across the country and the three major regions, and the eastern and central regions with a low synergy level have a higher convergence rate, indicating that as time goes by, under the influence of various factors, the synergistic effect will converge to the steady state level. The purpose of this paper is to analyze the spatial patterns and regional differences in the synergistic effects of pollution reduction and carbon reduction in Chinese provinces and also to provide a quantitative basis for the full implementation of the synergistic regulation of pollution reduction and carbon reduction.