Co-benefits of CO emission reduction from China's clean air actions between 2013-2020.

Climate change mitigation measures can yield substantial air quality improvements while emerging clean air measures in developing countries can also lead to CO emission mitigation co-benefits by affecting the local energy system. Here, we evaluate the effect of China's stringent clean air actions on its energy use and CO emissions from 2013-2020. We find that widespread phase-out and upgrades of outdated, polluting, and inefficient combustion facilities during clean air actions have promoted the transformation of the country's energy system. The co-benefits of China's clean air measures far outweigh the additional CO emissions of end-of-pipe devices, realizing a net accumulative reduction of 2.43 Gt CO from 2013-2020, exceeding the accumulated CO emission increase in China (2.03 Gt CO) during the same period. Our study indicates that China's efforts to tackle air pollution induce considerable climate benefit, and measures with remarkable CO reduction co-benefits deserve further attention in future policy design.