Wildfires and heatwaves undermining global air quality improvements, UN warns

The World Meteorological Organization warns that rising wildfires and heatwaves are undermining global air quality improvements. Extreme fire-smoke events have tripled since the 1990s, contributing to nearly 100,000 annual deaths. While industrial emissions regulations have succeeded in Europe and North America, exposure to toxic wildfire smoke and heatwave-induced ground-level ozone is rising, creating a dangerous feedback loop that accelerates climate breakdown.

Wildfire smoke health impacts

• ▪Wildfire smoke exposure is consistently linked to increased asthma attacks, hospitalizations for chronic obstructive pulmonary disease, spiked respiratory medication use, and adverse impacts on mental health and birth outcomes.
• ▪Extreme wildfires are increasing globally, producing highly toxic smoke that poses an urgent and growing public health threat.
• ▪A study cited in the World Meteorological Organization Bulletin states that extreme fire-smoke events have tripled globally since the 1990s, contributing to nearly 100,000 additional deaths per year between 2010 and 2018.
• ▪Microparticles generated by burning vegetation are more toxic than those emitted by other sources, including car exhaust, according to Lorenzo Labrador of the World Meteorological Organization.
• ▪Conventional risk models based on total PM2.5 concentrations may underestimate wildfire-attributable mortality by up to 93 percent, according to the World Meteorological Organization.

Climate-air quality feedback loop

• ▪Black carbon deposition has increased the melting of glaciers in the Himalayan region, leading to disastrous regional consequences.
• ▪The deposition of black carbon on snow and ice reduces the amount of sunlight reflected by these surfaces, which accelerates the melting process and reinforces global warming.
• ▪Air pollution and climate change are deeply intertwined, creating a feedback loop where worsening climate conditions exacerbate air pollution, which in turn accelerates climate breakdown.

PM2.5 monitoring gaps

• ▪A simulation in the World Meteorological Organization Bulletin estimates there are 51 million tonnes of microplastics on land and 22 million tonnes in the ocean, which act as a source of airborne microplastics.
• ▪The World Meteorological Organization stated that widespread air pollutants, including aerosols like black carbon and microplastics, fine particles, and ground-level ozone, are not sufficiently monitored despite being potentially harmful to ecosystems.

Ground-level ozone pollution

• ▪In heavily polluted regions, approximately one in five deaths from chronic obstructive pulmonary disease is attributed to long-term exposure to ground-level ozone.
• ▪Ground-level ozone accumulates when temperatures rise, atmospheric conditions stagnate, and solar radiation is intense, as seen during heatwaves in China, Europe, and the southeastern United States.
• ▪The World Meteorological Organization warned that increased exposure to ground-level ozone pollution has the potential to lead to tens of thousands of additional premature deaths, primarily due to respiratory diseases.

Regional air quality trends

• ▪While regulations in Europe and North America have successfully reduced industrial and transport PM2.5 emissions, human exposure to fire-related PM2.5 has increased.
• ▪In 2025, PM2.5 concentrations were above the long-term average in northern Canada, parts of Russia, western-central Africa, and northwestern Spain due to increased fire activity.
• ▪PM2.5 levels in China remained below the long-term average in 2025 due to declining emissions from human activities, while India continued to experience above-average levels due to biomass burning and other pollution.

Coordinated climate policy needs

• ▪The World Meteorological Organization and the World Health Organization called for complementary and coordinated policies on air quality and climate because the two issues cannot be dealt with in isolation.
• ▪Lorenzo Labrador of the World Meteorological Organization stated that the best solution to the dual crisis of air quality and climate change is a general abatement of global greenhouse gas emissions and fossil fuel burning.

Debatable claims

• ▪Air quality standards should differentiate between the toxicity of wildfire smoke and industrial emissions
• ▪Governments should integrate air quality regulations and climate change policies

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