Two three-month-old female white Bengal tiger cubs play with a zoo keeper in their enclosure at the Buenos Aires' Zoo, in Argentina, on April 17, 2014. Captive white Bengal tiger Cloe, gave birth to three cubs – two females and one male – on January 14, 2014. (Photo by Juan Mabromata/AFP Photo)

A man takes a selfie in front of a fire from oil that has been set ablaze in the Qayyarah area, some 60 kilometres (35 miles) south of Mosul, on October 19, 2016, during an operation by Iraqi forces against Islamic State (IS) group jihadists to retake the main hub city. In the biggest Iraqi military operation in years, forces have retaken dozens of villages, mostly south and east of Mosul, and are planning multiple assaults for October 20. (Photo by Yasin Akgul/AFP Photo)

Sandra, a 29-year-old orangutan at Buenos Aires' zoo, on May 20, 2015. Sandra got cleared to leave a Buenos Aires zoo that was her home for 20 years, after a court ruled she was entitled to more desirable living conditions. (Photo by Juan Mabromata/AFP Photo)

Contestants of a tourism beauty pageant balance eggs on their collarbones as they cruise along the Yellow River in Jiyuan, Henan province, China, June 22, 2015. The contestants believe that if they are slim enough, their collarbones will allow them to balance the eggs securely on their bodies. (Photo by Reuters/Stringer)

A Selkirk Rex cat is one of more than 400 breeds of cats being presented at the World Cat Federation two-day show in Dortmund, Germany, on April 21, 2013. (Photo by Frank Augstein/Associated Press)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

Water is seen on part of the glacial ice sheet that covers about 80 percent of the country is seen on July 17, 2013 on the Glacial Ice Sheet, Greenland. As the sea levels around the globe rise, researchers affilitated with the National Science Foundation and other organizations are studying the phenomena of the melting glaciers and its long-term ramifications. The warmer temperatures that have had an effect on the glaciers in Greenland also have altered the ways in which the local populace farm, fish, hunt and even travel across land. In recent years, sea level rise in places such as Miami Beach has led to increased street flooding and prompted leaders such as New York City Mayor Michael Bloomberg to propose a $19.5 billion plan to boost the citys capacity to withstand future extreme weather events by, among other things, devising mechanisms to withstand flooding. (Photo by Joe Raedle)

Zhang Jinduo's wife tries on a self-made racing car on the outskirts of Shenyang, Liaoning province May 10, 2008. Zhang, the 53-year-old local farmer made the racing car with the help of his son who is a car mechanic. The car is equipped with a rear-mounted motorcycle engine and can achieve 60-80 km per hour, according to local media. (Photo by Reuters/Stringer)