The Hidden Health and Climate Burden of Black Carbon under China's Dual Carbon Strategy.

Black carbon (BC) is a highly toxic air pollutant and potent short-lived climate pollutant. China's Dual Carbon strategy-peaking carbon emissions before 2030 and achieving carbon neutrality before 2060-has driven rapid BC emission reductions. However, global inventories still misrepresent BC emissions in China, biasing estimates of its health and climate impacts. Using a localized BC inventory and revised health risk function, we estimate that over 540,000 premature deaths were attributable to BC in China in 2015, more than twice previous reports. Conversely, the Coupled Model Intercomparison Project Phase 6 (CMIP6) inventory overestimates BC radiative forcing by 45%. Future projections show that demographic aging may offset health benefits from emission reductions. Our findings reveal that simulation based on CMIP6 inventory systematically underestimate health burden while exaggerating climate mitigation potential of BC. Accurate, region-specific assessments are urgently needed to guide integrated air quality and climate policies under the Dual Carbon goals.