Strategy for coordinating near-term PM <sub>2.5</sub> , ozone, and CO <sub>2</sub> mitigation in China
Yuxi Liu, Yuxi Liu, Yixuan Zheng, Guannan Geng, Jing Cheng, Yang Liu, Yang Liu, Dan Tong, Kebin He, Qiang Zhang
Abstract
China faces the challenge of simultaneously improving fine particulate matter (PM 2.5 ) and ozone (O 3 ) air quality while tackling climate change. However, most studies have focused on either the cocontrol of PM 2.5 and O 3 or the synergy between CO 2 reduction and PM 2.5 improvement, leaving comprehensive strategies for tackling all three underexplored. Here, we evaluate various combinations of clean-air and climate policies in China using an integrated framework that consists of a technology-based emission projection model, a goal-oriented measure selection and optimization method, a chemical transport model, and a detailed cost–benefit assessment approach. Our results show that while maintaining current clean-air policies is effective in controlling PM 2.5 , their impact on O 3 remains limited. Maximizing cost-effective end-of-pipe measures targeting NO x and volatile organic compounds can achieve cocontrol of PM 2.5 and O 3 , but remain vulnerable to unfavorable meteorological conditions. Near-term climate policies alone contribute limited improvements in air quality, particularly for O 3 , due to the lower synergy between CO 2 and O 3 precursor emission sources. Only a combined strategy, integrating stringent clean-air actions and ambitious climate mitigation, can achieve the “triple control” of PM 2.5 , O 3 , and CO 2 . Under this strategy, national annual mean PM 2.5 and national O 3 -8 h 90th percentile concentrations are reduced to 19.1 μg m −3 and 126.9 μg m −3 by 2030, respectively, yielding net benefits of over 3,000 billion RMB. Our findings can inform China’s next phase of environmental policies and emission control strategies in developing regions.