Heatwaves that are becoming more intense and frequent due to climate change are preparing a “diabolical potion” of pollutants that threatens people and all living things, the United Nations warned on Wednesday.
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While the smoke hazes created by the wildfires that suffocated Athens and New York this summer are the most visible part of air pollution caused by heat waves, they also trigger a whole range of more insidious and dangerous chemical processes for health.
“Heat waves deteriorate air quality and impact human health, ecosystems, agriculture and even our daily lives,” stressed the Secretary General of the World Meteorological Organization at the launch of the Air Quality and Climate Bulletin.
A recent study by the University of Chicago Energy Policy Institute (EPIC) found that fine particulate matter pollution – emitted by automobiles, industry and fires – represents “the greatest external threat to global public health.”
Climate change and air quality “go hand in hand and must be fought together to break this vicious circle,” stressed the head of the WMO, emphasizing that if the bulletin focuses on the data for 2022, “what we will see in 2023 see, is even more extreme”.
Climate change is increasing the frequency and intensity of heat waves, and this trend is expected to continue in the future.
On Wednesday, the European service Copernicus announced that the world had just experienced its three hottest months on record.
It is also the hottest August ever recorded and the second warmest month after July 2023.
There is a growing scientific consensus that heatwaves increase the risk and severity of wildfires, the WMO points out.
“Heat waves and forest fires are closely linked. Wildfire smoke contains a devilish potion of chemical elements that not only affects air quality and health, but also damages plants, ecosystems and crops – leading to more carbon emissions and therefore more greenhouse gases in the atmosphere,” explained Dr. Lorenzo Labrador, head of the Atmospheric Monitoring Network and author of the bulletin.
Dangerous romances
Although climate change and air pollutants such as ozone, volatile organic compounds and aerosols occur on very different timescales, the two are still linked.
“Air quality and climate are related because the chemical compounds that affect them are linked, because the substances responsible for climate change and deteriorating air quality are often emitted from the same sources, and because changes in one inevitably lead to changes in the other lead,” emphasizes the WMO.
Regarding the year 2022, the organization recalls that the long heat wave that hit Europe has led to an increase in the concentrations of particles and tropospheric ozone (just above the Earth’s surface).
And in most parts of the European continent, concentrations are above the WHO recommended level. In the second half of August 2022, unusually large masses of desert dust were observed over the Mediterranean and Europe.
“The combination of high temperatures and large amounts of aerosols and therefore particle levels has an impact on human health and well-being,” states the WMO.
Ozone concentration also reduces the quantity and quality of yield of staple crops.
“Globally, crop losses due to ozone in staple crops average 4.4 to 12.4 percent, with wheat and soybean losses reaching 15 to 30 percent in major agricultural areas of India and China,” the bulletin said.