A man stands near smoke billowing from a brick kiln in Karachi, Pakistan, 14 December 2018. According to the UN report, carbon dioxide (CO2) emissions have increased for the first time in four years. The United Nations Conference COP24, held in Katowice, Poland, until 14 December 2018, searches for a common position in the fight against climate change. (Photo by Shahzaib Akber/EPA/EFE)

A robot, developed by start-up firm Asimov Robotics, holds a tray with face masks and sanitizer after the two robots were launched to spread awareness about the coronavirus, in Kochi, India, March 17, 2020. (Photo by Sivaram V/Reuters)

This photo taken late on February 21, 2021 in Milo, near Catania, Sicily, and obtained on February 22, 2021 from Italian news agency Ansa, shows lava flowing along the sides of the southern crater of the Etna volcano as a new eruptive episode of tall lava fountains, known as paroxysm, occurred. (Photo by ANSA/Handout via AFP Photo)

A Tibetan living-in-exile in India attends a peace march during the 62nd Tibetan National Uprising Day in the suburb of McLeod Ganj, the seat of the Central Tibetan Administration in exile, near Dharamsala, India, 10 March 2021. Tibetan Uprising Day is held annually on 10 March and commemorates the Tibetan uprising against the presence of the People's Republic of China in Tibet in 1959. (Photo by Sanjay Baid/EPA/EFE)

A hummingbird feeds on the nectar from a Mimosa tree in Saugus, Massachusetts on July 30, 2020. (Photo by Joseph Prezioso/ZUMA Wire/Rex Features/Shutterstock)

Models get their makeup backstage during the Ukrainian Fashion Week in Kiev, Ukraine, 01 September 2020. (Photo by Sergey Dolzhenko/EPA/EFE)

Madagascan sunset setting over the 98-foot-tall baobab trees of the Avenue of the Baobabs located in Menabe, Madagascar on August 2020. (Photo by Kim Paffen/MediaDrumImages)

An orphaned giraffe nuzzling a wildlife keeper at Sarara camp in Kenya, one of 70 pictures being sold by Prints for Nature (printsfornature.com) to raise money for work by the Conservation International charity. This giraffe was rehabilitated and returned to the wild, as a number of others have done before him. Right now, giraffe are undergoing what has been referred to as a silent extinction. Current estimates are that giraffe populations across Africa have dropped 40 percent in three decades, plummeting from approximately 155,000 in the late 1980s to under 100,000 today. (Photo by Ami Vitale/National Geographic)