Abstract
Pathways for China to achieve its dual targets of air quality and CO
2
mitigation in 2035 were investigated through a newly developed evaluation framework coupling integrated assessment and air quality models. Results indicate that the low-carbon energy policies, traditionally regarded as a primary result of climate mitigation, are likely driven more by the efforts on air quality attainment in China. To achieve air quality attainment in China could lead to more reduction in CO
2
emissions than its Nationally Determined Contribution. In addition, stronger low-carbon policies will bring significant benefits to public health via improvements in air quality. This study also provides a valuable reference for other developing countries to address their duel challenges of climate change and air pollution.
China is challenged with the simultaneous goals of improving air quality and mitigating climate change. The “Beautiful China” strategy, launched by the Chinese government in 2020, requires that all cities in China attain 35 μg/m
3
or below for annual mean concentration of PM
2.5
(particulate matter with aerodynamic diameter less than 2.5 μm) by 2035. Meanwhile, China adopts a portfolio of low-carbon policies to meet its Nationally Determined Contribution (NDC) pledged in the Paris Agreement. Previous studies demonstrated the cobenefits to air pollution reduction from implementing low-carbon energy policies. Pathways for China to achieve dual targets of both air quality and CO
2
mitigation, however, have not been comprehensively explored. Here, we couple an integrated assessment model and an air quality model to evaluate air quality in China through 2035 under the NDC scenario and an alternative scenario (Co-Benefit Energy [CBE]) with enhanced low-carbon policies. Results indicate that some Chinese cities cannot meet the PM
2.5
target under the NDC scenario by 2035, even with the strictest end-of-pipe controls. Achieving the air quality target would require further reduction in emissions of multiple air pollutants by 6 to 32%, driving additional 22% reduction in CO
2
emissions relative to the NDC scenario. Results show that the incremental health benefit from improved air quality of CBE exceeds 8 times the additional costs of CO
2
mitigation, attributed particularly to the cost-effective reduction in household PM
2.5
exposure. The additional low-carbon energy polices required for China’s air quality targets would lay an important foundation for its deep decarbonization aligned with the 2 °C global temperature target.