A child walks to an installation made from fallen leaves by college students, in shape of a sofa, to call for people's attention to environment protection, in Hangzhou, Zhejiang province, China, December 6, 2016. (Photo by Reuters/China Daily)

A reveller takes part in an annual block party known as “Cordao de Prata Preta”, one of the many carnival parties to take place in the neighbourhoods of Rio de Janeiro, February 6, 2016. (Photo by Pilar Olivares/Reuters)

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

A picturesque supercell formation in the northwest of Booker, Texas from June 2013. (Photo by Mike Olbinski/Barcroft Media)

A dog sits in the shade of a mangrove tree as a woman uses a fork to dig for shellfish on the reef-mud flats of a lagoon located at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. (Photo by David Gray/Reuters)

Karis, an eleven week old lion cub, plays in fallen leaves brushed up by keepers in her enclosure at Blair Drummond Safari Park, near Stirling, Scotland, on November 20, 2013. (Photo by Andrew Milligan/PA Wire)

In this photo submitted by the Washington Post tilted “The Moment Time Stopped”, survivors piled bodies of the dead outside for weeks after earthquake on January 14, 2010 in Port-au-Prince, Haiti. The 7.0 magnitude earthquake struck in 2010, and the Haitian government has said more than 300,000 people were killed. The exact toll is unknown because there was no systematic effort to count bodies among the chaos and destruction. (Photo by Carol Guzy/AP Photo/The Washington Post)

Dilwyn Green, from North Wales, holds his 7 month old Gold Silkie Bantam which won a 1st prize in its breed at the Poultry Club's 2011 National Show on November 19, 2011 in Stoneleigh, England. (Photo by Oli Scarff/Getty Images)