Co-benefits of China’s climate policy for air quality and human health in China and transboundary regions in 2030

Abstract

Climate policies targeting CO₂ emissions from fossil fuels can simultaneously reduce emissions of air pollutants and their precursors, thus mitigating air pollution and associated health impacts. Previous work has examined co-benefits of climate policy from reducing PM₂.₅ in rapidly-developing countries such as China, but have not examined co-benefits from ozone and its transboundary impact for both PM₂.₅ and ozone. Here, we compare the air quality and health co-benefits of China's climate policy on both PM₂.₅ and ozone in China to their co-benefits in three downwind and populous countries (South Korea, Japan and the United States) using a coupled modeling framework. In a policy scenario consistent with China's pledge to peak CO₂ emissions in approximately 2030, avoided premature deaths from ozone reductions are 54 300 (95% confidence interval: 37 100-71 000) in China in 2030, nearly 60% of those from PM₂.₅. Total avoided premature deaths in South Korea, Japan, and the US are 1200 (900-1600), 3500 (2800-4300), and 1900 (1400-2500), respectively. Total avoided deaths in South Korea and Japan are dominated by reductions in PM₂.₅-related mortality, but ozone plays a more important role in the US. Similar to co-benefits for PM₂.₅ in China, co-benefits of China's policy for ozone and for both pollutants in those downwind countries also rise with increasing policy stringency. Keywords: climate policy; air quality; human health; co-benefits; transboundary air pollution