The World Meteorological Organisation (WMO) issued a warning on Monday that escalating wildfires and heatwaves are jeopardizing international efforts to improve air quality and protect public health. The UN agency highlighted the inseparable link between air pollution and climate change, noting that scientific evidence shows these factors are driving more frequent and intense extreme weather events.
“Extreme wildfires are increasing, leading to big health consequences because of the high toxicity of smoke,” the WMO stated in its annual Air Quality and Climate Bulletin. While regulatory measures in Europe and North America have successfully reduced industrial and transport-related PM2.5 emissions, exposure to fire-derived PM2.5 has risen concurrently.
PM2.5 consists of microscopic particles less than 2.5 micrometres in diameter that can penetrate deep into the lungs and bloodstream. These pollutants originate from fossil fuel industries, agriculture, domestic heating, transportation, as well as wildfires and dust storms.
Lorenzo Labrador, a scientist with the WMO’s Global Atmosphere Watch network, emphasized that air quality and climate change cannot be addressed in isolation. He noted that microparticles from burning vegetation are significantly more toxic than those from sources like car exhaust. Furthermore, these particles can travel long distances via wind, affecting human and wildlife health far from the fire zones.
The report cautioned that conventional risk models based on total PM2.5 concentrations may underestimate mortality attributable to wildfires by as much as 93 percent. Citing research, the WMO found that extreme fire-smoke events have tripled globally since the 1990s, contributing to nearly 100,000 additional deaths annually between 2010 and 2018, though this figure may be an underestimate.
Ground-level ozone was identified as another major health threat, accumulating during periods of high temperatures, stagnant atmospheric conditions, and intense solar radiation. Recent heatwaves in China, Europe, and the southeastern United States have exemplified this danger. The WMO warned that increased ozone exposure could result in tens of thousands of premature deaths, primarily from respiratory diseases.
The bulletin also drew attention to aerosol particles, including black carbon and microplastics, which can traverse oceans and continents. Black carbon deposited on snow and ice reduces surface reflectivity, accelerating melting. Meanwhile, microplastics, generated by the breakdown of plastic waste, are found in the air, soil, and oceans. Simulations estimate 51 million tonnes of microplastics on land and 22 million tonnes in the ocean, serving as ongoing atmospheric sources.
As plastic production and mismanaged waste continue to grow, the WMO stressed that monitoring the atmospheric pathways carrying microplastics to remote environments is crucial. The agency called for coordinated policies that address both air quality and climate change, arguing that current monitoring of widespread pollutants remains insufficient.
Interesting how car exhaust particles are less toxic than burning vegetation ones. Makes me wonder why our policies still prioritize tailpipes over fire risks.
Microplastics in the air are a nightmare I hadn’t fully considered. Five million tonnes in the ocean, yet here they are floating everywhere.
Ground-level ozone in the US Southeast during recent heatwaves was awful. The WMO warning aligns perfectly with what locals are experiencing right now.
So we cleaned up car emissions but ignored wildfire smoke? This feels like swapping one problem for an even deadlier one.
The 93 percent underestimation figure is terrifying. We need to update our models immediately to reflect smoke toxicity, not just volume.