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)

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)

2016 Rio Olympics, Judo, Final, Women, 48 kg Bronze Medal Contests, Carioca Arena 2, Rio de Janeiro, Brazil on August 6, 2016. Otgontsetseg Galbadrakh (KAZ) of Kazakhstan and Dayaris Mestre Alvarez (CUB) of Cuba react. (Photo by Kai Pfaffenbach/Reuters)

People follow king penguins exploring their outdoor pen, during a so-called “penguin parade”, when the animals walk outside their enclosure and the visitors can walk behind them, at Zurich's Zoo in Zurich, Switzerland January 28, 2017. (Photo by Arnd Wiegmann/Reuters)

A woman overcome by emotion after an aftershock hit the area, is carried by a relative to the general hospital in Port-de-Paix, Haiti, Sunday, October 7, 2018. A magnitude 5.2 aftershock struck Haiti on Sunday, even as survivors of the previous day's temblor were sifting through the rubble of their cinderblock homes. The death toll stood at 12, with fears it could rise. (Photo by Dieu Nalio Chery/AP Photo)

Elsa, Dolly, Jeanie, Vince, Titch and Bailey savour seaside smells at Reculver Towers and Roman Fort, Kent, United Kingdom on February 23, 2021. The southeast of England will be warm again. (Photo by Liz Gregg/Triangle News)

An elephant cools off at a zoo in Karachi, Pakistan, 31 March 2021. Caretakers at Karachi's zoo were working to keep animals cool during a​ heatwave affecting southern Pakistan. (Photo by Shahzaib Akber/EPA/EFE)

A light installation called “Run Beyond” by Angelo Bonello is seen on the launch day of the Light Festival at Battersea Power station on January 13, 2022 in London, England. Running from January 13 to February 27, the curated collection of installations includes work by six artists, with two displays making their UK exhibition debut. (Photo by Leon Neal/Getty Images)