Heat waves, more intense and frequent due to climate change, generate a “diabolical potion” of pollutants that threatens humans and all living beings, the UN warned on Wednesday.
The layers of smoke caused by fires that covered Athens and New York are the most visible part of the air pollution caused by heat waves, but they actually trigger a series of much more dangerous chemical processes for health.
“Heat waves degrade air quality, with repercussions for human health, ecosystems, agriculture and our daily lives,” said Secretary of the World Meteorological Organization (WMO), Petteri Taalas, at the presentation of the air quality and climate bulletin.
A recent study by the Energy Policy Institute at the University of Chicago (EPIC) found that fine particulate pollution – emitted by motor vehicles, industry and fires – represents “the greatest external threat to public health” worldwide.
Climate change and air quality “go hand in hand and must be fought together to break this vicious circle,” said the head of the WMO, warning that although the report deals with 2022 data, “what we see in 2023 is even more extreme.”
Climate change increases the frequency and intensity of heat waves, and this trend will continue in the future. The European Copernicus Observatory announced on Wednesday that average global temperatures during the three months of the boreal summer (June-July-August) were the highest since records began.
There is an increasingly established scientific consensus that heat waves will increase the risk and severity of wildfires, the WMO emphasized.
“Heat waves and forest fires are closely related. Smoke from forest fires contains a diabolical potion of chemicals that not only affects air quality and health, but also damages plants, ecosystems and crops – and leads to more carbon emissions and more greenhouse gas in the atmosphere,” said Lorenzo Labrador, author of the WMO bulletin.
Dangerous relationships
Although climate change and air pollutants (such as ozone, volatile organic compounds or aerosols) follow different stages, the two are related.
“Air quality and climate are interconnected because the chemicals that affect them are related, because the substances responsible for climate change and air quality degradation are often emitted from the same sources, and because changes in one inevitably lead to changes in the other,” the WMO reiterated.
The organization explains that in 2022, the long heat wave that shook Europe led to an increase in particle and tropospheric ozone concentrations (just above the earth’s surface).
And concentrations exceeded the level recommended by the WHO across most of the European continent. During the second half of August 2022, there were significant masses of desert dust over the Mediterranean and Europe.
“The coincidence of high temperatures and high amounts of aerosols and particulate matter affected human health and well-being,” the WMO noted.
The concentration of ozone also reduces the number and quality of crop yields.
“Globally, crop losses due to ozone average 4.4 to 12.4% for staple subsistence crops, losses of wheat and soybeans can reach 15 to 30% in major agricultural areas of India and China,” according to the bulletin.
