Air pollution has dropped to unprecedented levels across the world as major cities and countries impose lockdown measures to curb the spread of the coronavirus.

More than 2.6 million cases of Covid-19 and at least 183,820 deaths have been documented worldwide, according to Johns Hopkins University.

As humans stay inside, the environment is temporarily changing: wild animals are roaming the streets and some typically smog-filled skies are clear.

People in Punjab, India say they can see the snow peaks of the Himalayas, a view that for decades has been blocked by air pollution. New Delhi alone has recorded a 60% drop in fine particulate matter, the world's deadliest air pollutant.

Los Angeles, the traffic-congested city with some of the highest smog levels in the U.S., has seen nitrogen levels drop significantly and rush-hour traffic essentially vanish.

Despite the rare glimpse of natural beauty like snow-crested mountains and clearer skylines, scientists warn against celebrating any short-term benefits from the decline in air pollution since levels will rebound once global restrictions lift.