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)

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)

Rahma, 19 (L), pictured with her 10-year old brother Fahad on June 21, 2016 in Kano, Nigeria. A teenage girl born without limbs lives her life in a plastic bowl. Rahma Haruna is a bright, happy girl, despite suffering from a mystery condition that stopped her arms and legs developing properly – leaving her practically limbless and in constant pain. The 19-year- old, from Kano, Nigeria, was born a healthy baby but when she turned six months old her growth came to a sudden halt and she stopped hitting key development milestones. Rahma’s family do their best to provide her with a fulfilling life and transport her around the village in a plastic bowl. Rahma said: “They help me a lot. How do they? They give me anything I need”. Rahma died on 25 December 2016. (Photo by Sani Maikatanga/Barcroft Images)

Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)

Fashion fans pose outside the main catwalk venue during London Fashion Week Spring/Summer 2017 in London, Britain September 20, 2016. (Photo by Neil Hall/Reuters)

A married couple is displayed on a pile of cheeses in the “Speciality” category during the Swiss Cheese Awards competition in Le Sentier, Switzerland September 23, 2016. One hundred and fourty-two experts have to choose the best out of 777 cheeses from 353 producers competing in 28 categories. (Photo by Denis Balibouse/Reuters)

A hunter holds a hare he just killed during a hunt in a field near the village of Novosyolki, Belarus November 5, 2016. (Photo by Vasily Fedosenko/Reuters)

Zurab Gurielidze, a director of the Tbilisi Zoo, speaks to the media while standing next to a hippopotamus named Begi at the zoo in Tbilisi, Georgia, September 13, 2015. Tbilisi zoo, which was partly destroyed and some 300 animals escaped or died in the floods that also killed at least 19 people in June, was reopened on Sunday. (Photo by David Mdzinarishvili/Reuters)