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)

Dhofar Region, Oman. Much of Oman is desert, but the Arabian Sea coast in the Dhofar region represents a startling difference in climate. This coastal region catches the monsoon rains, or khareef, during the summer months. Drenching rains fall primarily on the mountainous ridge that separates the lush, fertile areas along the coast from the arid interior, recharging streams, waterfalls and springs that provide plentiful water supplies in the fertile lowlands for the remainder of the year. Image taken by Landsat 5 on April 2, 2005. (Photo by USGS/NASA)

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)

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)

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)

An armed man gestures in front of the police headquarters in Slaviansk, April 12, 2014. At least 20 armed militants wearing mismatched camouflage outfits took over the police and security services headquarters in the eastern city of Slaviansk seizing hundreds of handguns. (Photo by Gleb Garanich/Reuters)

A man wearing an armor attends a reenactment of the Battle of Agincourt, in Agincourt, northern France, Saturday, July 25, 2015. The French are hosting a reenactment of the clash with England this weekend. More than 800 people in Medieval garb are gathering at the site to commemorate the battle, which was a turning point in the Hundred Years' War. (Photo by Thibault Camus/AP Photo)