In the first report of its kind, the World Meteorological Organization examines the close link between air quality and climate change and how measures stemming from COVID-19 influenced air quality patterns in 2020.
Government-imposed lockdown measures and travel restrictions to control the spread of COVID-19 resulted in a marked improvement in air quality in many parts of the world. For example, the WMO said Southeast Asia experienced a 40% reduction in air particles in 2020.
However, the chief of the WMO’s Atmospheric Environment Research Division, Oksana Tarasova, said the dramatic fall in emissions of key air pollutants was short-lived. She said city dwellers who reveled in seeing blue skies during periods of lockdown inactivity, had to again endure living under a pollution cloud once the cars started rolling again.
“As soon as mobility has increased, we are back to business as usual," Tarasova said. "So, those improvements were not very long lasting. And that is why we always stress that the extreme measures which were taken under lockdown is not a substitute for long term policies.”
During this same period, the WMO said extreme weather events fueled by climate and environmental change triggered unprecedented sand and dust storms and wildfires that affected air quality.
In parallel with the human-induced experiment on lockdowns and travel restrictions, Tarasova said those, and other natural phenomena also were controlling air quality around the world.
“There were several very strong events that happened in 2020 related to bio-mass burning where the smoke pollution from this burning bio-mass impacted air quality in large parts of Siberia, the United States," Tarasova said. "Early in the year, there was an episode in Australia that caused dramatic deterioration of air quality in those parts of the world.”
The episode Tarasova refers is to Australian wildfires.
The WMO says changes in climate can influence pollution levels directly. It says the increased frequency and intensity of heatwaves may lead to greater accumulation of pollutants close to the surface. It notes the intense wildfires breaking out in many parts of the world and huge dust and sandstorms also worsen air pollution.
The weather agency warns air pollution has significant impacts on human health. That is borne out by estimates from the latest Global Burden of Disease assessment. The data show global mortality from pollution nearly doubled from 2.3 million in 1990 to 4.5 million in 2019 — most due to particulate matter.
