Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

Thailand's King Bhumibol Adulyadej in serious portrait January 01, 1960. Thailand's Royal Palace said on Thursday, October 13, 2016, that Thailand's King Bhumibol Adulyadej, the world's longest-reigning monarch, has died at age 88. (Photo by John Dominis/The LIFE Picture Collection/Getty Images)

Traders try to control a camel at Pushkar Fair where animals, mainly camels, are brought to be sold and traded in the desert Indian state of Rajasthan November 6, 2016. (Photo by Himanshu Sharma/Reuters)

Indian tourists walks during heavy snowfall by Dal Lake in Srinagar on January 6, 2017. The sub-zero temperatures has frozen many water bodies in Kashmir and even drinking water taps have frozen at some places. (Photo by Tauseef Mustafa/AFP Photo)

A dancer performs as visitors take pictures at an auto show in Tianjin, China April 28, 2016. (Photo by Reuters/Stringer)

A Muslim woman reads the Quran following noon prayers on the first day of the holy fasting month of Ramadan at Istiqlal Mosque in Jakarta, Indonesia, Monday, June 6, 2016. Devout Muslims began to celebrate Ramadan, the holiest month in the Islamic calendar, refraining from eating, drinking, smoking and sеx from sunrise to sunset. (Photo by Tatan Syuflana/AP Photo)