Impacts of Vegetation‐Driven BVOC Emissions on Ozone Pollution in the Beijing‐Tianjin‐Hebei Region Under a Carbon Neutrality Pathway

Abstract

To achieve air quality improvement and carbon neutrality, China is simultaneously implementing deep anthropogenic emission cuts and promoting large‐scale vegetation expansion. However, increased BVOC emissions from growing vegetation may counteract the air quality benefits of emission controls. Using the WRF‐Chem model for the Beijing‐Tianjin‐Hebei region, we find vegetation growth will increase July BVOC emissions by 13.8% in 2040 and 27.4% in 2060 from 2019 levels. Crucially, the impact on O ₃ depends on the stage of anthropogenic emission reductions. In 2040, increased BVOCs raise urban MDA8 O ₃ by 3.5 ppb, offsetting 47.0% of the benefit from emission controls. However, by 2060, deep emission reductions induce a transition to a NO _x ‐limited regime; consequently, the O ₃ penalty from BVOCs drops to 1.0 ppb (offsetting 7.0%). Our findings highlight that ignoring this strong BVOC‐NO _x ‐O ₃ interaction, which is highly dependent on the reduction stage, can lead to significant biases in evaluating long‐term air quality policies.