Disproportionate Effects of Direct Air Carbon Capture and Storage on Regional Health Cobenefits from Net-Zero Emissions.

Direct air carbon capture and storage (DACCS) is an emerging carbon dioxide removal (CDR) technology, but it may reduce the health cobenefits of climate mitigation by substituting for fossil-fuel phase-out that would otherwise reduce air pollutant emissions. The heterogeneity of these effects, however, remains unclear. By assessing grid-level (36 km2) air pollution-related mortality in China's pathway to net-zero CO2 emissions over 2020-2060, we show that, in addition to cumulatively causing an additional 1.75 million premature deaths, large-scale DACCS deployment exacerbates health inequity by disproportionately reducing health cobenefits in developing regions, while improving health equality by closing the gap among regional mortality rates. These impacts are largely attributed to more active emissions trading promoted by the development of DACCS. Despite increases in carbon emissions allowances in both developing and developed regions, the losses in health cobenefits are larger in developing regions such as Henan and Hebei, corresponding to 0.13 million and 0.12 million fewer avoided premature deaths, respectively. Our results support how health-considered policy can be incorporated into CDR deployment strategies to enhance health cobenefits and promote equitable health outcomes.