Air pollution continues to pose a major global health threat, contributing to over 4.5 million premature deaths annually, according to the latest bulletin from the World Meteorological Organization (WMO). While many regions are experiencing worsening air quality, the report highlights encouraging progress in parts of eastern China and Europe.
The WMO’s 2025 Air Quality and Climate Bulletin reveals that microscopic smoke particles from wildfires known as PM2.5 are spreading across continents, with high concentrations recorded in Chile, Brazil, Ecuador, Canada, central Africa, and Siberia. These fine particles, often invisible to the naked eye, are linked to respiratory illnesses and long-term health complications.
“Air quality respects no boundaries,” said Lorenzo Labrador, Scientific Officer at WMO. “Smoke from wildfires in the Iberian Peninsula has already reached Western Europe and can travel across the continent.”
Despite this troubling trend, the report notes that emission reduction efforts in cities like Shanghai are yielding results. Expanded green spaces, increased tree planting, and a shift toward electric vehicles have helped improve urban air quality. However, WMO experts caution that ground-level ozone an ingredient of smog remains stubbornly high due to climate-driven chemical reactions in the atmosphere.
“Climate change and air pollution must be tackled together,” said Ko Barrett, WMO Deputy Secretary General. “They are deeply interconnected and require coordinated global action.”
The bulletin also highlights the success of the Convention on Long-Range Transboundary Air Pollution, which has helped 51 countries in Europe and North America set binding emission limits. According to the UN Economic Commission for Europe (UNECE), the convention has saved approximately 600,000 lives annually and added a full year to life expectancy in the region.
Efforts are now underway to expand this science-policy model to other regions, including East and South Asia and South America, through international cooperation platforms.