A white yak sits on the lakeside of Namtso on May 19, 2024 in Lhasa, Xizang Autonomous Region of China. As temperature rises and ice melts, Lake Namtso is entering its tourism season. An event celebrating the melting of frozen water of Lake Namtso is held on May 19. (Photo by Jin Wei/VCG via Getty Images)

A swan sits on her eggs on nest made of rubbish found in the Danube river in Belgrade, Serbia on Monday, May 10, 2022. (Photo by Darko Vojinovic/AP Photo)

A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)

Mae Muller of the United Kingdom performs during dress rehearsals at the Eurovision Song Contest in Liverpool, England, Wednesday, May 10, 2023. (Photo by Martin Meissner/AP Photo)

In this Wednesday, September 17, 2014 photo, the sun shines over a field of sunflowers in Walkill, N.Y. (Photo by John DeSanto/AP Photo/Times Herlad-Record)

A woman fills her basket with marigold flowers, used to make garlands and offer prayers, as she plucks them before selling to the market for the Tihar festival, also called Diwali, in Kathmandu, Nepal on October 25, 2019. (Photo by Navesh Chitrakar/Reuters)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)

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)