Study finds climate-driven greening is reshaping East Asia's air pollution

Study finds climate-driven greening is reshaping East Asia's air pollution Sadie Harley Scientific Editor Alexander Pol Deputy Editor The effects of climate change extend far beyond rising temperatures. As forests and other vegetation respond to a warming world, they also change the amount of biogenic emissions released into the atmosphere, influencing the formation of ozone (O3) and fine particulate pollution. Yet many atmospheric chemistry models still estimate these emissions using vegetation data from 2003, despite major ecological changes across East Asia over the past two decades. A new study led by Professor Hyo-Jung Lee and Research Professor Yu-Jin Jo from Pusan National University, South Korea, together with Dr. Younha Kim from the International Institute for Applied Systems Analysis in Austria and researchers from Pusan National University, shows that updating vegetation information with recent satellite observations can significantly change estimates of biogenic emissions and air pollution. The study was published in Environmental Research . "Our results show that updating vegetation information alone can substantially change biogenic emissions, O₃ and biogenic secondary organic aerosols (BSOA)," Lee says. Plants emit biogenic volatile organic compounds (BVOCs), including isoprene and monoterpenes, which undergo atmospheric reactions and contribute to the formation of ground-level O3 and BSOA. Because these emissions depend on the amount and type of vegetation, changes in forests and plant growth can directly influence air quality. To investigate this effect, the researchers used the WRF-Chem atmospheric chemistry model coupled with the MEGAN biogenic emissions model. They replaced the model's default vegetation dataset from 2003 with satellite-derived vegetation observations from 2024 while using the same model configuration and meteorological conditions. This approach allowed the team to isolate the impact of updated vegetation data, specifically the effects of vegetation changes alone. Satellite observations showed an overall increase in vegetation across East Asia, but the magnitude and direction of change varied spatially, with strong greening in parts of China and localized declines in Japan. These vegetation changes altered modeled O₃ and BSOA concentrations, with the largest increases occurring in suburban areas, where a balance between vegetation changes and NOₓ availability favored secondary pollutant formation. Urban areas showed smaller responses because vegetation changes were limited despite high NOₓ levels, whereas rural areas showed smaller responses because NOₓ levels remained low despite substantial vegetation changes. "Our findings demonstrate that regularly updating vegetation datasets in biogenic emission modules can improve the accuracy of atmospheric chemistry models," Lee says. The researchers say the results highlight the importance of keeping vegetation datasets up to date as climate change continues to reshape ecosystems across East Asia. "This study highlights the importance of routinely updating vegetation datasets so that atmospheric chemistry models can more accurately represent changing ecosystems and their interactions with atmospheric chemistry," Jo says. The researchers say incorporating current satellite observations into atmospheric chemistry models could improve operational air quality forecasting and provide more reliable scientific information for air quality management under changing environmental conditions. They note that the study focused on August 2024, when vegetation activity is highest, and that future work will examine additional seasons and longer periods to better understand how changing vegetation will affect air quality in the years ahead. Publication details Seung-Hee Baek et al, Impacts of climate-driven vegetation changes on air quality over East Asia: Modulation of biogenic VOC emissions and secondary pollutants, Environmental Research (2026). DOI: 10.1016/j.envres.2026.124392 Journal information: Environmental Research Provided by Pusan National University