City-level synergy and co-benefits of mitigating CO 2 emissions and air pollution in China

Synergistic control of carbon emissions and pollutant concentrations can efficiently tackle climate change and air pollution. The synergistic performance and co-benefits yielded by controlling these factors are urgent and critical issues in China. Accordingly, a comprehensive indicator for assessing synergistic performance is pioneered, and co-benefits of mitigating CO and PM in Chinese cities are evaluated. Chinese synergistic performance is dominated by CO variations. In 2015-2020, multiple northeastern, central, southern, and eastern cities exhibited synergistic effects by greatly reducing CO emissions. The synergistic performance thereafter leads to co-benefits through environmental and economic feedbacks. The CO and PM controls in Northeast Chinese cities feature the most profound co-benefits of approximate 4800 CNY per capita, with each contributing 72 % and 28 %, respectively, to this total. The findings provide intercity synergistic performance and scientific support for policymaking.