The Aletsch Glacier is pictured at dusk in Fiesch, Switzerland, August 11, 2015. One of Europe's biggest glaciers, the Great Aletsch coils 23 km (14 miles) through the Swiss Alps – and yet this mighty river of ice could almost vanish in the lifetimes of people born today because of climate change. The glacier, 900 metres (2,950 feet) thick at one point, has retreated about 3 km (1.9 miles) since 1870 and that pace is quickening. (Photo by Denis Balibouse/Reuters)

A schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

Only 156 people remained in the tribe when Jan visited in Accham District, Nepal, January 2016. Hidden deep in the Himalayan forest is one of the world’s last enduring nomadic tribes who are resisting attempts to move them into permanent settlements. (Photo by Jan Moller Hansen/Barcroft Images)

A jockey rides a water buffalo during the annual Chonburi Buffalo Race in Chonburi on October 1, 2020. (Photo by Mladen Antonov/AFP Photo)

Frenchman Georges Speicher drinks as he starts riding down the Col de l'Aubisque during the 18th stage of the Tour de France between Tarbes and Pau. on July 17, 1933. Speicher finished second beaten by Spanish winner Learco Guerra to retain his overall leader's yellox jersey on his way to winning the Tour de France. (Photo by France Presse Voir/AFP Photo)

Frost covers part of the face of University of Minnesota student Daniel Dylla during a morning jog along Mississippi River Parkway Tuesday, January 29, 2019, in Minneapolis. Extreme cold and record-breaking temperatures are crawling into parts of the Midwest after a powerful snowstorm pounded the region, and forecasters warn that the frigid weather could be life-threatening. (Photo by David Joles/Star Tribune via AP Photo)

Malaysian firemen make their way to a designated area to spray disinfectant, in an effort to combat coronavirus and COVID-19, at the entrance to a school in Kuala Lumpur, Malaysia, 14 April 2020. According to media reports, Malaysia has confirmed over 4,000 cases of coronavirus and COVID-19. (Photo by Ahmad Yusni/EPA/EFE/Rex Features/Shutterstock)

Medical personnel jump in the COVID-19 unit at the CHR Centre Hospitalier Regional de la Citadelle Hospital, during the coronavirus disease (COVID-19) outbreak, in Liege, Belgium, April 22, 2020. (Photo by Yves Herman/Reuters)