Revelers jump on a rainbow painted crosswalk in Church Street, Toronto's LGBT neighbourhood, before “WorldPride”, a gay pride parade, in Toronto, June 29, 2014. Toronto is hosting WorldPride, a week-long event that celebrates the lesbian, gay, bisexual and transgender (LGBT) community. (Photo by Mark Blinch/Reuters)

A Sri Lankan activist, who wrapped himself with fire crackers, walks in Colombo on July 23, 2014 to symbolically demonstrate against people burned during Anti-Tamil riots on the island thirty-one years ago. Official accounts placed the death toll at 400 while human rights activists put the toll at thousands. (Photo by Ishara S.Kodikara/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)

Female sea lion “Sarasa” holds a hose with her mouse to help a trainer clean her room at the Shinagawa Aqua Stadium aquarium in Tokyo on December 30, 2014. The aquarium is carrying out year-end general cleaning of their facilities. (Photo by Yoshikazu Tsuno/AFP Photo)

Women wearing prosthetic legs participate in a public photo session at the Hasselblad and Profoto booth, during the CP+ camera and imaging equipment trade fair in Yokohama south of Tokyo, February 14, 2015. Japanese prosthetist Fumio Usui inspired the event after collaborating with photographer Takao Ochi in the book project “Amputee Venus” that portrays 11 Japanese women with artificial legs, local media reported. (Photo by Thomas Peter/Reuters)

This handout photograph released by Taipei City Zoo on July 11, 2013 shows a newly-born panda cub of giant panda Yuan Yuan in an incubator at Taipei Zoo in Taipei. The public will have to wait three months to catch a glimpse of the first panda born in Taiwan, officials said after she was successfully delivered by parents who were gifted from China. (Photo by AFP Photo/Taipei City Zoo)

A fishing boat that was ran aground by the sea while moored in the port of Coquimbo, some 445 km north of Santiago, during the eve's earthquake on September 17, 2015. A million people were evacuated in Chile after an 8.3-magnitude quake struck offshore in the Pacific, killing at least 10 people and triggering tsunami waves along its northern coast. (Photo by Martin Bernetti/AFP Photo)