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 March 2, 2018 photo, an Andean man rests with his llama while tourists take in the natural wonder of Rainbow Mountain in Pitumarca, Peru. Tourists gasp for breath as they climb for two hours to the 16,404-foot (5,000-meter) peak in the Peruvian Andes, but stunned by the magical beauty that unfurls before them. (Photo by Martin Mejia/AP Photo)

A woman is helped with adorning her hair with jewelry, part of the traditional clothing known as “Pollera”, before the annual Thousand Polleras parade in Las Tablas, in the province of Los Santos January 10, 2015. According to local residents, the Pollera dates back to the 18th century and was worn by the Spanish lower classes. Today, it has become the Panamanian national costume. The dress is made entirely by hand and the jewellery worn is pure gold and worth thousands of dollars. (Photo by Carlos Jasso/Reuters)

Belgian yoga teacher Dorien Dierckx, 29 from Brussels enjoys a beer while relaxing in a jacuzzi full of hot water and a mixture of ingredients used to make beer, and where customers can serve their own beer from the tap at the Good Beer Spa in Brussels, Belgium on May 12, 2021. (Photo by Yves Herman/Reuters)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

Moichara or Bull race is a rural festival where a pair of bulls race each other during the monsoon season. This race is performed by a farmer in Parganas, India on July 4, 2021. (Photo by Sumit Sanyal/SOPA Images/Rex Features/Shutterstock)

This picture taken on May 23, 2017 shows visitors posing for photos along a path at an Indonesian hamlet dubbed “the rainbow village” in Semarang, central Java, that has become an internet sensation and attracting hordes of visitors. (Photo by Suryo Wibowo/AFP Photo)

A person rides a swing hanging from a crane with hot air balloons fly in the background in Nevsehir, Turkey on October 14, 2021. Tourists and those who want to take photos set up swings on the cranes they rent and then have their photos taken in the setting created by hot air balloons in the backgrounds. (Photo by Behcet Alkan/Anadolu Agency via Getty Images)