No 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.

National commitments under the Paris Agreement on climate change interact with other global environmental objectives, such as those of the Minamata Convention on Mercury. We assess how mercury emissions and deposition reductions from national climate policy in China under the Paris Agreement could contribute to the country's commitments under the Minamata Convention. We examine emissions under climate policy scenarios developed using a computable general equilibrium model of China's economy, end-of-pipe control scenarios that meet China's commitments under the Minamata Convention, and these policies in combination, and evaluate deposition using a global atmospheric transport model. We find climate policy in China can provide mercury benefits when implemented with Minamata policy, achieving in the year 2030 approximately 5% additional reduction in mercury emissions and deposition in China when climate policy achieves a 5% reduction per year in carbon intensity (CO 2 emissions 9.7 Gt in 2030). This corresponds to 63 Mg additional mercury emissions reductions in 2030 when implemented with Minamata Convention policy, compared to Minamata policy implemented alone. Climate policy provides emissions reductions in sectors not considered under the Minamata Convention, such as residential combustion. This changes the combination of sectors that contribute to emissions reductions.

In the Supplementary Information PDF published with this Letter, under the heading 'Keywords used to select the papers for the literature review' , operator (*) use in the search strings is inconsistent and at times incorrect. In addition, the full list of references shortlisted from the Web of Science search criteria used in this study was not provided. The amended PDF is available as Supplementary Information to this Correction; those references not cited in the main paper and Methods have been included: refs 59-124 relate to mammals and refs 125-190 to birds.