Impacts of Climate-driven Biogenic VOC Emissions on Surface Ozone and Human Health in Guangdong Province of China in 2060s

As the precursor of ozone (O₃), volatile organic compounds (VOCs) largely derive from biogenic sources. However, future global changes in climate and land cover may profoundly affect O₃ by enhancing biogenic VOC (BVOC) emissions, posing new challenges to public health. In this study, we developed a coupled modeling framework under Shared Socioeconomic Pathways (SSP1-2.6 and SSP2-4.5), integrating chemical transport model and health impact assessment model to assess the impacts of climate and land-use-driven BVOC emissions on O₃ concentrations and human health in Guangdong Province with one of the highest BVOC emissions in China. Results indicate that BVOC emissions are projected to increase by 18.8% and 11.4% under SSP126 and SSP245 from 2023 to 2060. These increases will elevate warm-season MDA8 O₃ concentrations ranging from 0.6 to 7.6 μg·m⁻³ and 0.2 to 5.0 μg·m⁻³, respectively, offsetting 3.4 to 42.2% and 1.3 to 67% of the impact of anthropogenic emission reductions on O₃ control. Changes in BVOC emissions will increase by 6,817 cases (95% UI: 3306–10,328) and 4,798 cases (95% UI: 1915–7,681) O₃-related deaths under the SSP126 and SSP245, which is primarily driven by increased emissions and amplified approximately 2.4 times by population aging. Furthermore, the contribution of O₃-related deaths driven by BVOCs is projected to rise from 10.2 to 14.3% and 13.3%, concentrated in urban areas with high population density and NO_x availability. This study reveals the significant contribution of BVOCs to O₃ formation and human health under climate change, providing scientific evidence for developing policies that coordinate climate, environmental, and health objectives in regions experiencing persistent O₃ pollution.