Analysis of the present situation of greenhouse gases and air pollutants co-control in Guangdong-Hong Kong-Macao Greater Bay Area

Regional joint prevention and control can realize the coordinated emission reduction of greenhouse gases and air pollutants. Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has carried out a number of environmental cooperation projects, which has a good foundation for the co-control of climate change and air pollution. It is of great significance to study the current situation of the co-control of greenhouse gases and air pollutants at the regional level. Based on the historical data of 11 cities/regions in GBA from 2005 to 2020, a co-control evaluation index system of greenhouse gases and air pollutants was constructed by selecting 4 first-level indicators and 20 second-level indicators based on the global entropy method, and the coupling coordination degree model was used to measure the coupling degree of each indicator. The results showed that the comprehensive evaluation score of the co-control of greenhouse gases and air pollutants in GBA showed an upward trend, and the score of the eco-environmental level index lagged behind, which affected the improvement of the co-control level. The scores of co-control level of 11 cities/regions all had varying degrees of increase, but the score difference between the first-level indicators was larger. The coupling between the four subsystems was high coupling, and the coupling coordination degree was low coordination level. The subsystems were in the stage of coordinated development, and the interaction force between them was still small, so there was a large space for improvement. The different environmental management systems and environmental governance demands of the three areas were the main reasons that restricted the co-control development of greenhouse gases and air pollutants in GBA.