The adverse impact of climate policy uncertainty on air quality in China.

Climate policy uncertainty refers to the ambiguity, unpredictability, and lack of transparency in government policies, measures, regulations, and actions aimed at addressing climate issues. Previous studies have found that climate policy uncertainty affects carbon emissions. However, other environmental impacts of climate policy uncertainty have not been sufficiently analyzed in the literature. This study demonstrates that climate policy uncertainty has a negative impact on air quality in China. Based on data from 288 Chinese cities between 2001 and 2021, we find that climate policy uncertainty increases the concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), fine particulate matter (PM2.5), particulate matter with a diameter of 10 μm or less (PM10), and sulfur dioxide (SO2). Further analysis reveals that the impact of climate policy uncertainty exhibits regional heterogeneity. The effect is stronger in regions that rely more on fossil energy and have higher air pollution levels, but weaker in areas with greater clean energy adoption and lower pollution.