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)

Ground personnel work next to the Soyuz TMA-13M capsule of the International Space Station (ISS) crew of Alexander Gerst of Germany, Maxim Suraev of Russia and Reid Wiseman of the U.S. after its landing near the town of Arkalyk in northern Kazakhstan November 10, 2014. A veteran Russian cosmonaut and two International Space Station crewmates, one from the United States and one from Germany, returned safely to Earth on Sunday with a parachute landing of their Soyuz capsule in Kazakhstan, ending 5-1/2 months in orbit. (Photo by Shamil Zhumatov/Reuters)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

Indigenous dancers participate in a traditional healing ceremony for the mother earth at El Salvador del Mundo Square in San Salvador, December 10, 2014. Salvadorean indigenous organizations participated in a ceremony to ask for solutions to stop climate change and respect planet earth as the U.N. Climate Change Conference COP 20 is bring held in Peru. The two-week long United Nations climate summit opened on December 1 in Lima, with experts and analysts from around the world gathering to discuss melting glaciers and extreme weather patterns. (Photo by Jose Cabezas/Reuters)

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)

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)

A group of San Bushmen from the Khomani San community practice their hunter-gatherer craft in the Southern Kalahari desert on October 15, 2009 in the Kalahari, South Africa. One of the largest studies of African genetics by an international team from the University of Pennsylvania, published in April 2009, revealed that the San of Southern Africa are the most genetically diverse on earth, and that the San homeland could be the spot where modern humanity began. (Photo by Dan Kitwood/Getty Images)