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)

A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)

Korean Air flight attendants photograph a therapy dog dressed in a Superman Halloween costume, as part of a program to de-stress passengers at the international boarding gate area of LAX airport in Los Angeles, California, United States, October 27, 2015. (Photo by Lucy Nicholson/Reuters)

A villager watches as Mount Sinabung volcano erupts, in Kuta Tengah village, Karo Regency in Indonesia's North Sumatra April 1, 2015. The Indonesian volcano was dormant for 400 years before erupting in 2010. (Photo by Y. T. Haryono/Reuters)

A violent eruption spews ash more than a kilometer into the sky above Mount Etna in Sicily on February 23, 2021. (Photo by Marco Restivo/Barcroft Studios via Getty Images)

A mother bear acting as a taxi for her cubs and they jump on for a piggyback. Two sloth bear cubs fighting for the best place on mum's back as she carries them across Coonoor, India in July 2022. (Photo by Ranganathan Vasudevan/Media Drum Images)

A cosplayer visits an anime fair in Beijing, Thursday, July 21, 2022. (Photo by Ng Han Guan/AP Photo)

Vehicles move past a man resting on a taxi, as he waits for passengers, along a road in Karachi, Pakistan, May 5, 2015. (Photo by Akhtar Soomro/Reuters)