First lockdown’s effect on air pollution was overstated, our study reveals
Charles Rotter
Zongbo Shi, University of Birmingham and William Bloss, University of Birmingham
The pandemic caused governments around the world to introduce lockdowns in early 2020, temporarily closing workplaces and emptying roads and public spaces. As economic activity slowed, so did emissions of air pollutants. Almost a year later, the effect that all this had on the air we breathe is becoming clear.
The most straightforward way to determine the effects of lockdown on air quality is to compare measurements before and after the date that the lockdown began. Earlier studies used this approach and reported big reductions in some pollutants, such as nitrogen dioxide (NOâ‚‚). One study claimed that NOâ‚‚ emissions fell by up to 90% in Wuhan (the Chinese city where COVID-19 is believed to have emerged) at the peak of the outbreak.
But this comparison is misleading. The weather also affects levels of pollution by, for example, dispersing emissions from cities. More fossil fuels are burned for heating during the winter compared with the spring too, and the pollutants formed tend to react differently in the atmosphere under different conditions of sunlight and temperature, causing air pollution levels to vary between seasons. These factors obscure the
influence of a single event on air pollutant concentrations.
https://wattsupwiththat.com/2021/01/13/first-lockdowns-effect-on-air-pollution-was-overstated-our-study-reveals/
