Tourists kissing front of Malaysia's landmark Petronas Twin Towers with lights on before turned off to mark Earth Hour 2016 in Kuala Lumpur, Malaysia, 19 March 2016. Earth Hour takes place worldwide at 8.30 p.m. local time and is a global call to turn off lights for 60 minutes to raise awareness of the danger of global climatic change (Photo by Fazry Ismail/EPA)

These are the dunes of the Namib Desert, taken by Korea's Kompstat-2 satellite. The blue and white area is the dried riverbed of the Tsauchab river. (Photo by The European Space Agency)

Wladimir Klitschko (R) of Ukraine hits out at David Haye (L) of England during their World Heavyweight unification fight at the Imtech Arena on July 2, 2011 in Hamburg, Germany. (Photo by Martin Rose/Bongarts/Getty Images)

The buffalo bull charges, on March 23, 2014, in Addo Elephant National Park, South Africa. A young elephant calf tried to attack an old buffalo bull and was taught a lesson it will never forget. The calf was with its herd at a watering hold Addo Elephant National park, South Africa, when the buffalo ventured towards the water. The elephant ran towards the buffalo but the larger animal picked up the young calf and tossed it four metres in the air. Luckily, the elephant was not hurt, but its pride was seriously injured. (Photo by Conrad Cramer/Barcroft Media)

The Soyuz TMA-11M capsule with the International Space Station (ISS) crew members Japanese astronaut Koichi Wakata, Russian cosmonaut Mikhail Tyurin and U.S. astronaut Rick Mastracchio lands south-east of the town of Dzhezkazgan in central Kazakhstan, May 14, 2014. The first Japanese to command a space mission and crewmates from the United States and Russia landed safely in Kazakhstan on Wednesday, wrapping up a 188-day stay aboard the International Space Station. (Photo by Dmitry Lovetsky/Reuters)

An unidentified guest wears a hat with a lion at the Grand Palais which is transformed into a Chanel airport before German designer Karl Lagerfeld's Spring/Summer 2016 women's ready-to-wear collection for French fashion house Chanel during Fashion Week in Paris, France, October 6, 2015. (Photo by Benoit Tessier/Reuters)

Model Cara Delevingne is surrounded by photographers as she arrives to attend German designer Karl Lagerfeld's Spring/Summer 2016 women's ready-to-wear collection show for fashion house Chanel at the Grand Palais which is transformed into a Chanel airport during the Fashion Week in Paris, France, October 6, 2015. (Photo by Charles Platiau/Reuters)

An old toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. The exhibition focuses on how the toilet has changed our daily lives and discovers what the most environment-friendly and ideal toilet is. (Photo by Keith Tsuji/Getty Images)