Pandemic brings 'short-lived' air quality gains

GENEVA (AN) — Lockdowns and travel restrictions due to the coronavirus pandemic resulted in a "dramatic short-lived fall in emissions of key air pollutants" last year, the World Meteorological Organization reported on Friday.

The fall in human-caused emissions of air pollutions during the COVID-19 economic downturn — with fewer cars on the road, restricted gatherings and shuttered offices and schools — particularly benefited cities, WMO said, though the decrease was not consistent among all regions or each of the main pollutants, which include fine particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide and ozone.

The U.N. weather agency said the findings from its first Air Quality and Climate Bulletin show "an intimate connection between air quality and climate change," with the trend continuing this year as sand and dust storms affect many regions and wildfires foul the air that millions of people breath in Europe, North American and Siberia. The findings are taken from measurements in 63 cities among 25 nations around the world.

“COVID-19 proved to be an unplanned air quality experiment, and it did lead to temporary localized improvements,” WMO Secretary-General Petteri Taalas said. “But a pandemic is not a substitute for sustained and systematic action to tackle major drivers of both population and climate change, and so safeguard the health of both people and planet.”

Climate, fires and air quality

Fossil fuel burning has both long-term and short-term effects on the atmosphere. It emits carbon dioxide, a long-lasting greenhouse gas, and nitrogen oxides, which can lead to short-lived ozone and particulate matter, both harmful to health.

Worsening air pollution caused by particulate matter and ozone led to 4.5 million deaths in 2019, up from 2.3 million in 1990, according to WMO's bulletin.

Taalas said the impacts of these air pollutants are usually a local occurence, daily and weekly, near the Earth's surface, in contrast to the effects of climate change that are generally global, over decades and centuries, in the atmosphere. However, there is a need to integrate policies on both, he added.

In regions that were unusually hot and dry last year, intense wildfires like those in Siberia and the western United States caused high concentrations of particulate matter in the air. But smoke from the wildfires in Australia also temporarily cooled the Southern Hemisphere by blotting out the sun.

U.S. space agency NASA studied satellite images of the wildfires to estimate that the increased levels of air pollution from the wildfires caused a "high" or "very high" health risk for up to 50 million people, mostly in the western U.S. and regions downwind.