Study reveals climate greening increases East Asia's air pollution by 15%

A new study shows that climate‑driven greening across East Asia is reshaping the region’s air quality by altering the amount of natural emissions that feed ozone and fine‑particle pollution. Researchers found that as forests and other vegetation respond to higher temperatures, they release more biogenic substances into the atmosphere. These substances can react with other gases to form ozone (O₃) and contribute to the growth of fine particulate matter (PM₂.₅), both of which pose serious health risks.

The changes in vegetation cover have been driven by warming temperatures, longer growing seasons, and shifts in precipitation patterns over the last two decades. Yet many atmospheric chemistry models still rely on vegetation maps from 2003, when the region’s forests were less extensive and compositionally different. This mismatch means that models may underestimate or misrepresent the natural emissions that feed air‑pollution chemistry. The study highlights that updated vegetation data are essential for accurately predicting air‑quality trends in a warming world.

According to the research, the increase in natural plant emissions could raise ozone precursor levels by as much as 10–15 % in some parts of China, Korea, and Japan. The resulting higher ozone concentrations could elevate health risks for millions of people, especially in densely populated urban areas. Fine‑particle pollution, which is also influenced by these natural emissions, could see a similar upward trend, compounding respiratory and cardiovascular problems. The study also notes that these shifts could alter the seasonal patterns of air‑quality peaks, making it harder for cities to anticipate and mitigate pollution events.

The findings call for an urgent update of air‑quality models to incorporate recent vegetation changes. Policymakers and public‑health officials will need to consider these new projections when designing mitigation strategies. Future research will likely focus on refining the link between greening, natural emissions, and pollution chemistry, as well as exploring how land‑use changes might further influence these dynamics. Accurate modeling will be key to protecting public health as East Asia continues to grapple with the dual challenges of climate change and air‑quality management.