Co-Control of CO2 and SO2 Emissions in the Key Environmental Protection Prefectures in China

Chinese cities are facing serious environmental issues and climate change challenges at the same time. Because most energy in China is based on coal combustion, almost all air pollutants are related to carbon dioxide (CO2) emission. Using the Emission Database for Global Atmospheric Research (EDGAR) database and prefecture boundary data, studies comparing CO2 and sulfur dioxide (SO2) emissions of 113 key environmental protection cities in China were conducted using statistical analysis. The results showed that significant correlation existed between CO2 and SO2 emissions in these cities. Clustering analysis showed that these cities could be categorized into four groups, with 57% of the prefectures emitting low CO2 and SO2 emissions. Obviously, clustering was observed in typical prefectures and agglomeration areas, such as the top ten cities for SO2 emission in China; the CO2 and SO2 emissions from these ten cities accounted for 10.71 and 13.15% of the total national emissions, respectively, although these cities took up less than 3% of the country’s land area. In the top ten cities of CO2 emission in China, the CO2 and SO2 emissions accounted for 15.30 and 10.45% of the total national emissions, respectively, although these cities took up less than 2% of the country’s land area. The implication of these findings for policymakers is that prefectures should be the focus of future strategies designed for the co-control of development, rather than concentrating only on the provinces. Prefectures with low CO2 and SO2 emissions or low CO2/SO2 ratios should be provided with incentives related to synergistic measures that can be used to achieve the dual control of CO2 and SO2 emissions at a lower cost.