Increasingly severe wildfires and heat waves could undermine worldwide efforts to improve air quality and protect public health, the World Meteorological Organization said Monday, warning that climate change is making international pollution targets harder to achieve.
In its annual report examining the relationship between air quality and climate, the United Nations weather agency said the two issues are closely connected and should be addressed through coordinated policies rather than separately.
The WMO also warned that more frequent extreme wildfires could make it increasingly difficult for countries to meet air quality guidelines established by the World Health Organization.
Wildfires Emerging as a Major Pollution Source
Wildfires are becoming an increasingly significant source of dangerous air pollution, even as regulations have helped reduce emissions from industry and transportation across many developed countries.
Lorenzo Labrador, a scientific officer at the WMO, told Reuters that even areas with relatively clean air can experience deteriorating conditions when smoke from large wildfires reaches them.
The report focuses particularly on fine particulate matter known as PM2.5 and ground-level ozone, both of which are associated with respiratory and cardiovascular diseases. It also highlights the need for better monitoring of pollutants and aerosols such as black carbon and microplastics, which remain inadequately tracked despite their widespread presence in the atmosphere.
Smoke Pollution Raises Health Concerns
Europe has experienced extreme heat and destructive wildfires this year, including major fires in Spain, France and Greece. The WMO has said that as the planet warms, extreme heat is becoming more frequent, more intense and longer-lasting.
The new report found that PM2.5 levels in 2025 exceeded long-term averages in northern Canada, parts of Russia and western-central Africa, where increased fire activity contributed to higher pollution. Northwestern Spain also emerged as a hotspot after exceptional fires late in the summer.
A study cited by the WMO found that extreme wildfire-smoke events have tripled worldwide since the 1990s. The study estimated that such events may have contributed to almost 100,000 additional deaths each year between 2010 and 2018.
Wildfire particulate matter poses a particular danger because it contains numerous toxic chemicals, Labrador said. Breathing in the particles can trigger inflammation throughout the body and contribute to pulmonary disease.
The WMO said stronger pollution monitoring and coordinated action on both air pollution and climate change will be increasingly important as extreme weather and wildfire activity intensify.
