Can carbon emission trading policy enhance the synergistic emission reduction of carbon dioxide and air pollutants? A comparative study considering different pollutants

Exploring the synergistic control of carbon dioxide and pollutants is significant to the dual carbon target. This study first evaluates the effect of CET on the synergistic emission reduction of carbon dioxide and different pollutants. Moreover, this study investigates the mechanisms of synergistic emission reduction through the pathways of technology progress and structure adjustment. Technology progress is categorized into technology research and development, technology introduction, reverse technology spillover and technology purchase. Structure adjustment contains industrial structure and energy structure. Finally, the impact of CET on the synergistic emission reduction in the surrounding regions is analyzed. The results indicate that the CET could promote the synergistic emission reduction of carbon dioxide and pollutants, including air pollutants (SO 2 , PM 2.5 ), wastewater and solid waste. The synergistic emission reduction of CO 2 and SO 2 could be enhanced through reverse technology spillover, technology purchase and industrial structure adjustment. The synergistic emission reduction of CO 2 and PM 2.5 could be enhanced through R &D and reverse technology spillover. The synergistic emission reduction of carbon dioxide and ammonia nitrogen could be enhanced by increasing R &D, technology purchase and energy structure adjustment. The CET could improve the synergistic emission reduction effect of carbon dioxide and air pollutants in the surrounding regions.