Quantifying the Synergistic Benefits of Air Quality Improvement and Carbon Emissions Reduction: A Case Study of Henan, China

Sustainable development goals link policies addressing air quality and energy efficiency to synergistic benefits for climate mitigation. However, the coal-dominated energy system poses major challenges for Henan Province in mitigating air pollution and climate change. While the government has issued a series of clean air policies and low-carbon energy targets, the simultaneous achievements of low-carbon transition and air quality goals at the sub-national level remain unclear. This study evaluates the effectiveness of policy implementation in Henan’s energy system using an integrated assessment framework that combines emission scenarios, air quality simulations, and health impact assessments. The results indicated that, by 2030, without system-wide energy transformation driven by carbon mitigation policies, air quality improvements in Henan Province will be limited, even under stringent end-of-pipe emission control measures. In contrast, low-carbon policies would yield significant co-benefits for both air quality improvement and climate mitigation. Beyond stringent end-of-pipe controls, the implementation of carbon mitigation policies aligned with China’s enhanced climate targets could further reduce Henan’s average PM_2.5 concentration by up to 4.1 µg/m³. The monetized health co-benefits in Henan Province would reach 4.57 billion RMB under the stringent carbon mitigation scenario. These results highlight the critical role of effectively implementing existing air pollution and energy policies in simultaneously achieving air quality, public health, and carbon mitigation goals in Henan.