The impact of winter clean heating in northern China on air quality and its spatial spillover effect of the pilot cities

Air pollution is a serious environmental problem China has faced in recent years, with winter coal combustion being one of the main sources of air pollution in the northern region. Based on meteorological and economic statistical data from 285 Chinese cities, this study uses the spatial Durbin Difference-in-Difference model to evaluate the actual effect on air quality of the winter clean heating pilot implemented in the northern region since 2017. Our research found that: (1) Pilot policy significantly reduced the level of pollutants in cities, and the air quality index (AQI) score decreased by 3.798. Six air pollutants that make up AQI, including PM_2.5, PM₁₀, SO₂, CO, and NO₂, reduced by 5.637 μg/m³, 9.724 μg/m³, 7.386 μg/m³, 0.219 mg/m³, and 1.34 μg/m³ respectively. But O₃ concentration increased instead. (2) The pilot policy has a spatial spillover effect on the emission reduction of several pollutants, but it has not significantly affected the AQI of other cities. (3) By comparing the effect between heating and non-heating periods, the clean heating pilot policy mainly improved the AQI in winter, due to the increased usage of clean energy such as electricity and natural gas. The above results indicate that, as an energy transition project, the clean heating policy in China had a significant effect on relieving air pollution. Developing countries are recommended to accelerate the promotion of clean energy substitution and update facilities to improve energy efficiency, in order to improve local environmental quality and protect the residents' health.