Future air quality and human health benefits of net-zero CO2 emissions pathway in China

While growing attention has been paid to the co-benefits of climate policies, existing research often lacks granularity in evaluating diverse low-carbon transition strategies and their effects on air pollution and public health, particularly within the context of China's rapidly aging demographic. Here, we assess the PM_2.5 air quality and health co-benefits of a net-zero CO₂ emissions (NZE) pathway aligned with the 1.5 °C global climate target by integrating the Greenhouse Gas-Air Pollution Interactions and Synergies model with updated exposure-response relationships. Compared with China's initial nationally determined contribution scenario – peaking CO₂ emissions around 2030, the NZE pathway reduces SO₂, NO_x and PM_2.5 emissions by roughly 3900 kt, 4500 kt and 770 kt, respectively, by 2050. These reductions lower national population-weighted PM_2.5 concentrations to 18.9 μg/m³, preventing approximately 260,000 premature deaths annually. Guangdong, Shandong, Henan, Sichuan, Jiangsu, and Hubei provinces account for 44 % of the avoided deaths, highlighting significant spatial disparities. Despite these improvements, PM_2.5-related mortality reductions plateau after 2035, suggesting that climate policy alone may not fully offset health risks from population aging and residual pollution. Nationally, the marginal health benefits of CO₂ abatement rise over time, reaching 77 avoided deaths per million tons of CO₂ reduced by 2050, with particularly high values in Beijing and Hainan. The coefficient of variation for avoided PM_2.5-related premature deaths per unit CO₂ abatement rises from 1.12 in 2035 to 1.60 in 2050, indicating growing regional inequality. Our findings demonstrate that ambitious decarbonization delivers pronounced air quality and public health benefits while emphasizing the need for regionally tailored policies to ensure equitable outcomes.