'Witches brew' of harmful air pollutants created globally from wildfires: WMO
A recent World Meteorological Organization (WMO) report pinpointed Canada's role in contributing to poor air quality levels worldwide in 2024 as a result of its wildfires––part of a global review of trends and geographical distribution of air pollution last year
With Canada experiencing its second-worst wildfire season on record, the World Meteorological Organization (WMO) said the fires are playing a significant role in creating unsafe air quality worldwide, also pinpointing the "complex interplay" the latter has with climate change.
Wildfires across the globe--not just in Canada--are contributing to the decline in poor air quality, with a focus on 2024 impacts, as they release aerosols into the atmosphere.
SEE ALSO: Canada endures another tough wildfire season. Can AI be a major help?
Thew new air quality and climate bulletin from the WMO, released on Sept. 5, highlighted the trends and geographical distribution of air pollution in 2024, as well as the progress and challenges in forecasts and warnings.
The WMO cited a statistic from the World Health Organization (WHO) that estimates the premature death toll from ambient air pollution is more than 4 million worldwide every year. It also comes with significant environmental and economic costs.
Mount Underwood wildfire in B.C. August 2024. (BC Wildfire Service/X)
“The wildfire season has the tendency to be stronger and longer every year as a result of climate change,” said Lorenzo Labrador, WMO scientific officer, at a Sept. 4 United Nations (UN) press conference on global air pollution.
'Witches brew' of air pollutants found across the globe from wildfires
WMO touched upon four specific issues that are causing worsening air quality, including aerosols in wildfires, winter fog, shipping emissions and urban pollution.
Labrador, who organized the Sept. 5 WMO bulletin, said "what we have from these fires is essentially a witches’ brew of components that pollute the air.”
“We had that last year and this year, as well. So you have a degradation in air quality across continents when the meteorological conditions are right,” said Labrador.
A sizable portion of particle pollution comes from wildfires. The issue is anticipated to get worse as the climate warms, WMO said, creating more risks to infrastructure, ecosystems and human health.
(Mark Robinson/The Weather Network)
Wildfires in Canada have contributed to air pollution in Europe, in 2024 and 2025. Earlier this year, a plume of wildfire smoke travelled 7,000 kilometres across the Atlantic Ocean to reach the skies over Europe.
“Climate impacts and air pollution respect no national borders––as exemplified by intense heat and drought, which fuels wildfires, worsening air quality for millions of people. We need improved international monitoring and collaboration to meet this global challenge,” said Ko Barrett, WMO Deputy Secretary-General, in a news release.
Other sources of pollution include black carbon, nitrous oxide and ground-level ozone, which all contribute to and exasperate climate change, WMO said, calling it a "vicious cycle."
WATCH: Risk of dementia linked to traffic pollution: New study
Particulate matter levels above average in Canada in 2024
Fine particulate matter (PM2.5) refers to particles suspended in the air that are less than 2.5 micrometres (μm) in diameter. The amount of particles found in transport, industry and agriculture, as well as from wildfires and wind-blown desert dust, remains a significant health hazard, WMO says.
Its latest bulletin said above-average levels of PM2.5 were found in Canada as a result of the extreme wildfire season in 2024. Levels were also higher than usual in Siberia and central Africa. Meanwhile, it found pollution hot spots in northern India, but PM2.5 levels were on the decline again in eastern China as a result of its mitigation measures in place.
PM2.5 explainer. (U.S. Environmental Protection Agency (EPA))
Canada also saw an increase in fine particulate matters indoors in early June, with Airthings saying that its data indicated PM2.5 levels soared to unsafe levels in homes across the country.
But the highest anomaly in the PM2.5 levels was found in the Amazon basin. The levels can be blamed on record-setting wildfires in the western Amazon and drought-created blazes in northern South America.
The report also called for improved atmospheric monitoring and more integrated policies to protect human and environmental health, and reduce agricultural and economic losses that come as a result.
Air quality monitoring station. (Getty Images/silkwayrain/499257975-170667a)
As part of the call for mitigation measures, the UN agency said it's critical for worldwide, fit-for-purpose, atmospheric monitoring infrastructure to be in place, particularly for developing nations.
"Observations are foundational. Satellites provide critical insights, but ground-based monitoring networks are essential for calibration and validation, particularly in developing countries where infrastructure remains sparse," said WMO in the news release.
WATCH:What do those air quality numbers actually mean?
Thumbnail courtesy of Getty Images-172296371.
With files from Connor O'Donovan, a video journalist at The Weather Network.