Greek actress Xanthi Georgiou, playing the role of the High Priestess, lights up the torch during the flame lighting ceremony for the Beijing 2022 Winter Olympics at the Ancient Olympia archeological site, birthplace of the ancient Olympics in southern Greece on October 18, 2021. The Olympic flame will once again be lit in an empty stadium on Ovtober 18, 2021, as it starts its truncated journey to Beijing for the Winter Games in February. Like the ceremony in March 2020 to light the flame for Tokyo, and like those Games, which were put back a year, Monday's ceremony is a victim of coronavirus restrictions. (Photo by Aris Messinis/AFP Photo)

Toure, a Gambian salt harvester, holds a basket filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by Marco Longari/AFP Photo)

This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when it expands to become a red giant and then sheds most of its outer layers, leaving behind a hot core that contracts to form a dense white dwarf star. This image was released October 10, 2012. (Photo by J. Kastner/NASA/CXC/RIT)

People look at the “Dragon de Calais” by Francois Delaroziere and La compagnie La Machine during a rehearsal in the harbour of Calais, France on October 30, 2019. (Photo by Pascal Rossignol/Reuters)

Justin Nelzen, in red vest, joins others as they work to rescue up to 70 horses along Cypresswood Drive near Humble along Cypress Creek, Monday, April 18, 2016, in Houston. More than a foot of rain fell Monday in parts of Houston, submerging scores of subdivisions and several major interstate highways, forcing the closure of schools and knocking out power to thousands of residents who were urged to shelter in place. (Photo by Mark Mulligan/Houston Chronicle via AP Photo)

Spur Lacasse of Cochrane, Alberta rides the horse Rebel Warrior in the novice bareback event during the Calgary Stampede rodeo in Calgary, Alberta, in this July 12, 2014 file photo. (Photo by Todd Korol/Reuters)

The Greenland ice sheet is a vast body of ice covering 660,235 sq miles, roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after the Antarctic Ice Sheet. Some scientists predict that climate change may be near a "tipping point" where the entire ice sheet will melt in about 2000 years. If the entire 2,850,000 cubic kilometres (683,751 cu mi) of ice were to melt, it would lead to a global sea level rise of 7.2 m (23.6 ft).

Guardian of the Mangroves – Overall Winner. Tanya Houppermans, Cuba. A curious American crocodile (Crocodylus acutus) swims right up to Tanya, at Gardens of the Queen (Jardines De La Reina), an archipelago off the coast of Cuba. It has been strictly protected since 1996, and is one of the most untouched marine ecosystems in the world. ‍ “The healthy population of American crocodiles is down to the pristine condition of the mangroves and I wanted to capture close ups of this gentle giant in its natural habitat. I hope this image can illustrate that protecting areas like this is so critical”. (Photo by Tanya Griffin Houppermans/Mangrove Photographer of the Year)