Analysis of the Environmental Effects of the Clean Heating Policy in Northern China

This article estimates the impact of the “Clean Heating Plan in Northern China (2017–2021)” on air quality improvement. It is a significant policy to promote the clean heating rate in Northern China, while there is limited research into its effects. We used a difference-in-difference model to qualify the effects of this policy on the “2 + 26” cities. For this, we controlled factors such as economy, energy use, afforestation level, and weather. We found that: (1) the clean heating plan makes the “2 + 26” cities’ AQI index, PM2.5, PM10, NO2, and O3 significantly decrease; (2) the concentrations of SO2 and CO increase. After adjusting the treatment group and control group, the results are still robust. We believe that the rise of SO2 is due to the shortage of natural gas supply in the 2017–2018 heating season in China, which led to the blockage of clean heating. Therefore, in promoting clean heating in Northern China, it is necessary to strengthen the estimation of heating demand, fully consider the energy structures of different regions, and implement the “reform by gas”.