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 Indonesian woman watches an eruption from the Mount Sinabung volcano from Tiga Pancur village, in Karo in North Sumatra on November 3, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

A Los Angeles County Fire helicopter flies over during the “Skirball Fire” which began early morning in Bel-Air, California, USA, 06 December 2017. An outbreak of several fires North of Los Angeles has occurred as one of the strongest Santa Ana winds forecast of the season is ongoing and expected to last several days. (Photo by John Cetrino/EPA/EFE)

A zoo staff feeds crocodiles as visitors look on at the Malabon Zoo in Malabon City, north of Manila, Philippines 21 December 2017. Wearing Santa Claus hats for the upcoming Christmas season, owner Manny Tangco (R, holding megaphone) and some select animals gave visitors a tour of the 28-year-old zoo. (Photo by Rolex Dela Pena/EPA/EFE)

Sinabung mountain spews volcanic smoke in Tiga Pancur Village, Karo, North Sumatra, Indonesia, 09 June 2019. According to BNPB, Mount Sinabung erupted, blowing volcanic ash more than 7,000 meters high. Sinabung is one of the most active volcanos in Indonesia. It erupted in 2010 and since then killed 17 people in eruptions in 2014 and another nine people in 2016. (Photo by Sarianto Sembiring/EPA/EFE)

A flood affected boy on a makeshift banana raft collects biscuit packets distributed by a government official from a boat in Pokoria village, east of Gauhati, north eastern Assam state, India, Monday, August 14, 2017. Heavy monsoon rains have unleashed landslides and floods that killed dozens of people in recent days and displaced millions more across northern India, southern Nepal and Bangladesh. (Photo by Anupam Nath/AP Photo)

Cory Ritz braces himself as a wave bursts onto a pier at the Boynton Beach inlet on August 25, 2011 in Boynton Beach, Florida. Hurricane Irene is moving over the Bahamas and could still be a major storm as it approaches the North Carolina coast the morning of August 27. (Photo by Joe Raedle/Getty Images)

A Siberian tiger cub is seen at the Hengdaohezi Breeding Center for Felidae on October 26, 2007 in Harbin of Heilongjiang Province, China. Established in 1986, the breeding center is one of the world's largest captive breeding base for Siberian tigers. Distributed throughout northeastern China, far eastern Russia and North Korea, over 400 Siberian tigers exist in the wild, approximately 20 in China. (Photo by China Photos/Getty Images)