A devotee looks at the camera as she offers prayers to the setting sun during the “Chhath” festival at Bagmati River in Kathmandu, Nepal on October 26, 2017. (Photo by Navesh Chitrakar/Reuters)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

People watch plumes of smoke and ash rise from as Taal Volcano erupts Sunday January 12, 2020, in Tagaytay, Cavite province, outside Manila, Philippines. (Photo by Aaron Favila/AP Photo)

A man stands in front of a poster created by artist Tomoko Konoike, one of 20 posters officially selected for the Tokyo Olympics and Paralympics, at the Museum of Contemporary Art Tokyo Monday, January 6, 2020. The official posters are out for this year's Tokyo Olympics and Paralympics. The 20 posters have been created by 19 artists in fields ranging from painting, graphic design, and photography. Calligraphy and Japanese manga are also represented. (Photo by Jae C. Hong/AP Photo)

A girl from Newar community is pictured with vermillion powder on her forehead as she takes part at the Ihi ceremony in Bhaktapur, Nepal on December 6, 2019. The two-day ceremony begins with purification rituals and ends with “Kanyadan” (giving away the virgin) of the girl by her father. A Newari girl gets married thrice in her life, first with Bel, the fruit of a wood-apple tree, secondly with the sun, and lastly with her future husband. (Photo by Monika Deupala/Reuters)

A female tourist wears a protective face mask on the street, following an outbreak of the coronavirus disease (COVID-19), in Tokyo, Japan on March 10, 2020. (Photo by Hannibal Hanschke/Reuters)

An member of the group “Pause the System” wears a face mask as she protests in front of the entrance to Downing Street in London, Friday, March 20, 2020. For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. (Photo by Frank Augstein/AP Photo)

Pedestrians cross a road in Cape Town, South Africa Saturday, March 28, 2020, as South Africa went into a nationwide lockdown for 21 days in an effort to control the spread of the coronavirus. (Photo by Nardus Engelbrecht/AP Photo)