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)

An Indian villager walks back home with a bicycle loaded with grass for his cattle during a heavy downpour on the outskirts of Bhubaneswar, India, Saturday, 11 July 2015. (Photo by Biswaranjan Rout/AP Photo)

Sunrise over a moor viewed from Littaford Tor, Dartmoor, UK, 2016. Autumn visits the windswept moors and granite tors of Dartmoor earlier than the rest of the south-west. While there aren’t many trees here, autumn shades appear in golden ferns and tan heather. Littaford Tors, near Two Bridges and a mile from Princetown, is a short walk and can be combined with a visit to the adjacent Wistman’s Wood. (Photo by Stuart Holmes)

A truck driver cleans the mirror of his decorated truck in Charsadda outside Peshawar, Pakistan October 18, 2016. (Photo by Fayaz Aziz/Reuters)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

A woman walks past a caricature of Britain's Foreign Secretary Boris Johnson in east London, Britain November 18, 2016. (Photo by Andrew Winning/Reuters)

A Maasai moran athlete has his face smeared with red ocher paint during preparations for the 2016 Maasai Olympics at the Sidai Oleng Wildlife Sanctuary, at the base of Mt. Kilimanjaro, near the Kenya-Tanzania border in Kimana, Kajiado, Kenya December 10, 2016. (Photo by Thomas Mukoya/Reuters)

A woman walks past a stall at a market in Banjul, Gambia December 15, 2016. (Photo by Afolabi Sotunde/Reuters)