A participant takes part in a “Zombie Walk” parade in Kiev, Ukraine on October 27, 2018. (Photo by Gleb Garanich/Reuters)

Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

An artist gets ready backstage to perform an Indian art form of dance called “Ottamthullal” at the annual eight-day long Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum and trumpets concerts, at Sree Poornathrayeesa temple in Kochi, India, December 7, 2018. (Photo by Sivaram V/Reuters)

A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

Former Vice President Joe Biden, 2020 Democratic presidential candidate, right, watches as his wife Jill Biden, center, blocks a protester from arriving on stage during an primary night rally in the Baldwin Hills neighborhood of Los Angeles, California, U.S., on Tuesday, March 3, 2020. The biggest day of the presidential primary calendar will define the nomination fight for Bernie Sanders and Biden and determine whether Michael Bloomberg and Elizabeth Warren have a rationale for carrying on their campaigns. (Photo by Patrick T. Fallon/Bloomberg via Getty Images)

A person viewing the Northern lights over the lava landscape, Reykjanes Peninsula, Iceland. (Photo by Arctic-Images/Getty Images)

A cat sits in the flooding waters from Hurricane Matthew in downtown Nichols, South Carolina, October 10, 2016. (Photo by Randall Hill/Reuters)

A labourer rides a donkey cart through a flooded street after heavy monsoon rains in Lahore on August 20, 2020. (Photo by Arif Ali/AFP Photo)