Impacts of future land use and land cover changes on air quality in China

Land use and land cover changes (LULCCs) influence air quality via modifications in local meteorology and natural emissions, yet their future impacts and pathway contributions remain inadequately quantified. Here, we employed an online coupled meteorology–chemistry model to assess the effects of LULCCs by the mid-21st century on O3 and PM2.5 in China, and to disentangle the roles of meteorological influences versus biogenic volatile organic compound (BVOC) emission changes. Our results show that, with anthropogenic emissions and meteorological fields fixed at current conditions, LULCCs under SSP1-2.6 and Afforestation scenarios (characterized by forest expansion) induce a summer cooling of 0.04 °C and 0.09 °C in China but raise summertime daily maximum 8-h O3 by 1.8 µg/m3 and 4.7 µg/m3 due to the dominance of BVOC-driven enhancement. Meanwhile, afforestation triggers north–south and seasonal variations in PM2.5 changes: winter decreases in the north but increases in the south, with the pattern reversing in summer, resulting in a net national increase. Conversely, deforestation under SSP5-8.5 would cause warming but reduce BVOC emissions, slightly lowering summer O3 (−0.8 µg/m3) and winter PM2.5 (−0.1 µg/m3) across China. These findings underscore the potential importance of incorporating land-use strategies to support future integrated climate and air quality governance.