Aquarium visitors attend a dinner party in an underwater tunnel in Tianjin, China on September 15, 2016. Tianjin Haichang Polar Ocean World opened in the city of Tianjin, southeast of Beijing, in 2010. It gives visitors a chance to see more than 150 large animals from the Arctic and Antarctic regions, including polar bears. (Photo by Feature China/Barcroft Images)

In this Tuesday, July 29, 2014, photo, Syrian refugee Samah, 5, poses for a picture at Zaatari refugee camp, near the Syrian border, in Mafraq, Jordan. More than 2.8 million Syrian children inside and outside the country – nearly half the school-aged population – cannot get an education because of the devastation from the civil war, according to the U.N. children's agency, UNICEF. That number is likely higher, as UNICEF can't count the children whose parents didn't register with the United Nations refugee agency. (Photo by Muhammed Muheisen/AP Photo)

Women playing in the street as the snow falls on Johannesburg for the first time in seventeen years. (Photo by Keystone/Getty Images). 1st September 1962

Two rainbows emerge from a black storm above the mountains, on August 19, 2014, in Kingman, Arizona. Double tornadoes, lightning storms and rotating supercells – this is what it's like to chase storms for a year. These dramatic images show apocalyptic weather throughout 2014 from a lightning storm to a pair of rainbows. Roger Hill, 57, has been chasing storms in the United States for thirty years and runs a tour operation with his wife Caryn. His favourite photograph of the year was also one of the most difficult to get – as two violent tornadoes tore through Pilger, Nebraska on June 16. The spiraling winds killed a five-year-old girl and injured at least 19 others, and as Roger tried to get the perfect shot debris began to rain down on his car. (Photo by Roger Hill/Barcroft Media)

A Thai villager runs with a bullock during a catching a bullock competition as part of the annual bullock cart racing festival in Phetchaburi province, Thailand, 21 February 2016. The annual bullock cart race festival held to celebrate the end of the harvest season. (Photo by Rungroj Yongrit/EPA)

A Tampa Bay Buccaneers cheerleader during the second quarter of an NFL preseason football game against the Cleveland Browns Friday, August 26, 2016, in Tampa, Fla. (Photo by Jason Behnken/AP Photo)

Residents watch the forest burn in Portezuelo, Chile, Sunday, January 29, 2017. Chilean President Michelle Bachelet has announced that the country will continue with its various measures to deal with wild fires, one of the biggest natural disasters in the country for decades, according to a government report released on Sunday. (Photo by Esteban Felix/AP Photo)

Brazilian navy soldiers watch a woman as they patrol the area at the Copacabana Beach before carnival festivities in Rio de Janeiro, Brazil February 14, 2017. (Photo by Sergio Moraes/Reuters)