A reef shell lies on a beach as the sun sets on Lady Elliot Island located north-east of the town of Bundaberg in Queensland, Australia, June 10, 2015. UNESCO World Heritage delegates recently snorkelled on Australia’s Great Barrier Reef, thousands of coral reefs, which stretch over 2,000 km off the northeast coast. Surrounded by manta rays, dolphins and reef sharks, their mission was to check the health of the world's largest living ecosystem, which brings in billions of dollars a year in tourism. Some coral has been badly damaged and animal species, including dugong and large green turtles, are threatened. UNESCO will say on Wednesday whether it will place the reef on a list of endangered World Heritage sites, a move the Australian government wants to avoid at all costs, having lobbied hard overseas. Earlier this year, UNESCO said the reef's outlook was “poor”. (Photo by David Gray/Reuters)

Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Russian people walk during heavy rain in Moscow, Russia on 17 September 2020. Over two hours a third of the monthly average rainfall fell in Moscow. (Photo by Yuri Kochetkov/EPA/EFE)

A child in colorful kimono walks at Tokyo's Asakusa district on the occasion of Shichigosan celebration Thursday, October 22, 2020. The festival celebrates children aged three, five and seven for their well-being. (Photo by Eugene Hoshiko/AP Photo)

Activists from the climate action group Ocean Rebellion perform a stunt outside The Baltic Exchange building, in London, Britain on November 16, 2020. (Photo by Henry Nicholls/Reuters)

An activist is juggling next to police officers at the Dannenrod forest, during a protest of environmentalists against the extension of the A49 motorway, near Dannenrod, Germany, November 27, 2020. (Photo by Kai Pfaffenbach/Reuters)

A man dressed in Christmas garb smokes a hand-rolled cigarette, Thursday, December 24, 2020, in Times Square on Christmas Eve in New York. (Photo by Kathy Willens/AP Photo)