Does low carbon energy transition impede air pollution? Evidence from China's coal-to-gas policy

Low carbon energy transition is deemed a viable way to fulfill the commitments outlined in the Paris Agreement and COP 26, which aims to restrict the rise in global temperature to 1.5 °C. One of the pivotal energy transition strategies in China, the coal-to-gas policy has been ambiguously executed, and its environmental impact remains unclear. In this context, this study employs the synthetic control method to examine the effects of the coal-to-gas policy on air pollution in pilot areas and explore its impact mechanism. The specific findings are as follows: (1) The concentration of PM2.5 in China experienced a declining trend, ranging from 15.684 to 15.204, while and the growth rate of PM2.5 concentration exhibited considerable fluctuations. (2) The coal-to-gas policy significantly contributed to a reduction in air pollution in pilot areas, except for Henan Province, where it exacerbated air pollution. In 2020, the policy's effects led to a decrease in air pollution levels by 1.73% in Beijing, 0.83% in Tianjin, 0.90% in Hebei, 1.63% in Shandong, and 0.64% in Shanxi, while air pollution levels in Henan Province increased by 0.34%. (3) The implementation of the coal-to-gas policy reduces air pollution by accelerating the transformation of the economic development and energy structure, as well as increasing foreign investment and technological investment.