The UN weather agency says the world experienced a brief, sharp drop in emissions of air pollutants last year amid lockdown measures and travel restrictions put in place because of the coronavirus pandemic.
The World Meteorological Organization, releasing its first air quality and climate bulletin on Friday, said the decline was especially noticeable in urban areas, but it cautioned that reductions in pollution were patchy.
Many parts of the world showed pollution levels that outpaced air quality guidelines, and some types of pollutants emerged at even higher levels, reports UNB quoting the Geneva-based agency.
WMO cited drops in average nitrous oxide levels of up to nearly 70 per cent during full lockdowns last year, compared to the same periods from 2015 to 2019. But ozone levels, for example, stayed at similar levels or even rose.
"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," WMO Secretary-General Petteri Taalas said.