Synergy of pollution control and carbon reduction in China: Spatial-temporal characteristics, regional differences, and convergence

Promoting the synergy of pollution control (PC) and carbon reduction (CR) is an important strategy for ecological civilization construction in China. Based on constructing a measuring system for PC and CR respectively, we employ the coupling coordination model to determine the coupling coordination degree (CCD) between PC and CR in 30 Chinese provinces during 2006-2019, and analyze the spatial-temporal characteristics, regional differences, and convergence of the CCD between PC and CR from a dual perspective of east-west and south-north regional divisions. The results show that the average CCD between PC and CR increases from 0.8339 in 2006 to 0.8904 in 2019, suggesting that the two subsystems are in a well-coordinated stage. Moreover, China's CCD shows a "high in the east and low in the west, high in the south and low in the north" layout and exhibits a prominent spatial positive autocorrelation characteristic. Furthermore, the overall regional differences in the CCD of each province show an increasing trend initially, followed by a decreasing trend. The overall differences in east-west and south-north originate primarily from the cross-regional and within-regional difference, respectively. The results of the convergence model show that there is no sigma convergence of China's CCD, while there exists beta convergence in China and different regions. These findings provide empirical evidence and policy implications for facilitating the synergistic effect of PC and CR.