Geneva: More frequent and intense heatwaves and wildfires driven by climate change are expected to worsen the quality of the air we breathe, harming human health and ecosystems, the UN warned Wednesday.
A new report from the UN's World Meteorological Organization (WMO) cautioned that the interaction between pollution and climate change would impact hundreds of millions of people over the coming century, and urged action to rein in the harm.
Impact: Wildfires across Siberia and western North America
The WMO's annual Air Quality and Climate Bulletin examined the impacts of large wildfires across Siberia and western North America in 2021, finding that they produced widespread increases in health hazards, with concentrations in eastern Siberia reaching "levels not observed before".
Tiny particles with a diameter of less than 2.5 micrometres (PM2.5) are considered particularly harmful since they can penetrate deep into the lungs or cardiovascular system.
"As the globe warms, wildfires and associated air pollution are expected to increase, even under a low emissions scenario," WMO chief Petteri Taalas said in a statement.
"In addition to human health impacts, this will also affect ecosystems as air pollutants settle from the atmosphere to Earth's surface."
Foretaste of the future
At the global scale, there has been a reduction over the past two decades in the total burned area, as a result of decreasing numbers of fires in savannas and grasslands.
But WMO said that some regions like western North America, the Amazon and Australia were seeing far more fires.
Even beyond wildfires, a hotter climate can drive up pollution and worsen air quality.
Taalas pointed out that severe heatwaves in Europe and China this year, coupled with stable high atmospheric conditions, sunlight and low wind speeds, had been "conducive to high pollution levels," warning that "this is a foretaste of the future."
Heatwaves: Climate penalty
”We expect a further increase in the frequency, intensity and duration of heatwaves, which could lead to even worse air quality," he said.
This phenomenon is known as the "climate penalty", which refers to how climate change amplifies ground-level ozone production, which negatively impacts air quality.
In the stratosphere, ozone provides important protection from cancer-causing ultraviolet rays, but closer to the ground it is very hazardous for human health.
If emission levels remain high, this climate penalty is expected to account for "a fifth of all surface ozone concentration increase," WMO scientific officer Lorenzo Labrador told reporters.
Asia in focus
He warned that most of that increase will happen over Asia, "and there you have about one quarter of the entire world population."
The WMO called for action, stressing that "a worldwide carbon neutrality emissions scenario would limit the future occurrence of extreme ozone air pollution episodes."
The report points out that air quality and climate are interconnected, since chemicals that worsen air quality are normally co-emitted with greenhouse gases.
"Changes in one inevitably cause changes in the other," it said.
Searing summer temperatures in the UK have not just parched the earth and dried up rivers, lakes and reservoirs but are also seeing trees shed their leaves early.
The early leaf fall observed in the UK - dubbed a “false autumn” - is a sign of stress, as trees shed their leaves to try to retain moisture. But experts say while older trees with deep roots can withstand the drier conditions, younger, less established ones could be at risk.
Instead of green, many gardens, parks and woods are now a sea of orange, yellow, red and brown, with thick carpets of leaves on the ground.
Temperatures soared above 40 degrees Celsius (104 degrees Fahrenheit) for the first time in Britain in July, with the month the driest on record in many parts of southern and eastern England. Climate change has been blamed for the searing heatwave, which has led to drought being declared and a ban on the use of hosepipes to save water in some areas. That, and the premature ripening of other berries and nuts, could hit wildlife such as small mammals and birds who store energy in September and October for the cold winter months.
The climate crisis is bringing with it seasonal weather patterns which our wildlife is just not adapted to. Experts say the long, hot summer and the ‘false autumn’ will have a knock-on for many species right into the real autumn months and beyond.
