Can carbon emission reduction mitigate the PM2.5 air pollution? Evidence of the co-benefits from mitigating climate change

The determination of the correlation between CO2 and PM2.5 emissions quantifies the co-benefits of air pollution reduction from the pursue of global warming mitigation. Using data on 186 countries or regions from 2010 to 2014, we evaluated the relationship between CO2 and PM2.5 from a global perspective. Based on the static and dynamic panel data models, we found a negative correlation between CO2 and PM2.5 emissions worldwide, but not a significant dynamic relationship between them. Through the regression clustering analysis, we found that there are significant differences in the relationship between CO2 emissions and air pollution across clusters of countries or regions. To understand this phenomenon, we evaluated the moderating effect of energy consumption on the relationship between CO2 and PM2.5 emissions and try to adjust this undesirable relationship. We found that an increase in oil and nature gas consumption would exacerbate the negative relationship between CO2 and PM2.5 emissions, while the consumption of renewable energy and coal, albeit in opposite directions, can strengthen their positive relationship. Therefore, we suggest to vigorously achieve a positive relationship between CO2 and PM2.5 emissions by an extensive use of renewable energy and curb oil and nature gas consumption globally. Furthermore, countries are left to choose climate club architectures based on the co-benefits according to their cluster's characteristics.