Abstract
Abstract
Global surface ozone (O
3
), intensified by climate change, poses increasing health and ecosystem threats. Despite stringent air policies, China’s persistent O
3
pollution exemplifies a global challenge intertwined with climate actions reshaping emission pathways. Optimal mitigation remains contentious, primarily due to inconsistent conclusions regarding the sensitivity of summer regional O
3
formation. Here we show the path dependency in O
3
mitigation strategies for synergistic clean air and climate action goal achievement over multidecade scales. This path dependence is validated by observed concurrent plateaus (2020-2023) in deweathered O
3
concentrations and sensitivity trends across Chinese megacity clusters. Leveraging this understanding of path dependency, we quantitatively reveal that the optimal future strategy involves prioritizing early volatile organic compound reductions, as their high effectiveness for regional O
3
mitigation gradually diminishes towards 2050. This challenges prevailing nitrogen oxides priority paradigms. Our work reframes O
3
control, providing a paradigm for resilient air quality-climate governance.