The World Meteorological Organization (WMO) warns: heat waves and forest fires will become more frequent, more intense and longer under the effect of climate change, and will thus degrade air quality and human health . In its new report, published on Wednesday September 7, the specialized agency of the UN evokes a dynamic of mutual reinforcement between pollution and global warming which will lead to a “climatic aftershock” from which hundreds of millions of people will suffer.
WMO’s annual Air Quality and Climate Bulletin focuses specifically on the impact of wildfire smoke in 2021 when, as in 2020, heat and drought exacerbated the spread forest fires in western North America and Siberia, leading to a considerable increase in levels of fine particles (PM 2.5) harmful to health.
“According to projections, even if emissions are low, global warming will cause an increase in forest fires and the air pollution they cause.”
Petteri Taalas, WMO Secretary Generalin a press release
The Finnish meteorologist points out that this phenomenon will have an impact on human health, but will also affect ecosystems because atmospheric pollutants are deposited on the surface of the Earth.
The year 2022 was a “taste”
Global observations show that the total annual area burned shows a downward trend over the past two decades, thanks to a decrease in the number of savannah and grassland fires. However, on a continental scale, some regions show increasing trends, including areas of western North America, the Amazon and Australia.
Intense forest fires thus resulted in abnormally high concentrations of PM 2.5 in Siberia, Canada and the western United States in July and August 2021. In eastern Siberia, these concentrations reached levels that had not previously been observed. “never observed before”according to the WMO, mainly due to particularly high temperatures and dry soils.
As for what happened this year, it’s “a taste of what the future holds, as a further increase in the frequency, intensity and duration of heat waves is to be feared”predicts Petteri Taalas.