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 degrees 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.