UN: Wildfires Creating 'Witches' Brew' of Air Pollution

The World Meteorological Organization (WMO) said the quality of the air people breathe was interlinked with climate change, and the two issues needed to be tackled together.

Wildfires in the Amazon, Canada and Siberia have brought home how air quality can be impacted on a vast scale, the WMO said in its fifth annual Air Quality and Climate Bulletin.

"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," said WMO Deputy Secretary-General Ko Barrett.

The bulletin looked at the interplay between air quality and the climate, highlighting the role of tiny particles called aerosols in wildfires, winter fog, shipping emissions and urban pollution.

Particles with a diameter of less than 2.5 micrometers (PM 2.5) are considered particularly harmful since they can penetrate deep into the lungs or cardiovascular system.

Wildfires in 2024 led to above-average PM 2.5 levels in Canada, Siberia and central Africa, the WMO said. The biggest PM 2.5 surge, however, was in the Amazon basin.

"The wildfire season has the tendency to be stronger and longer every year as a result of climate change," said WMO scientific officer Lorenzo Labrador, who coordinated the bulletin.

Wildfires in Canada have ended up causing air pollution in Europe.

"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," Labrador told a press conference.

"What we have from these fires is essentially a witches' brew of components that pollute the air."