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 performer is seen floating in mid-air as he holds onto a moving bus during the International Magic Festival in Luoyang, Henan province, China September 11, 2016. (Photo by Reuters/China Daily)

Yu Jietao, 26-year-old wood carver, sits in his homemade wooden car along a street in Guangfeng county of Shangrao, Jiangxi province, China February 9, 2015. The car can travel as fast as 30 km (18.6 miles) per hour, local media reported. (Photo by Reuters/Stringer)

A boy plays with a toy plane on the eve of a solar eclipse, in La Higuera, Coquimbo Region, in the Atacama desert about 580 km north of Santiago, on July 1, 2019. A total solar eclipse will be visible from small parts of Chile and Argentina on July 2. (Photo by Martin Bernetti/AFP Photo)

A Sri Lankan man use a scarf as a protective mask as he waits for a swab test at a locked-down area in Colombo, Sri Lanka, 14 May 2020. The Sri Lankan government has started lifting most of the restrictions implemented nearly two months ago in a bid to slow down the spread of the SARS-CoV-2 coronavirus causing the COVID-19 disease and is preparing for a full reopening of businesses and a resumption of activities to avoid an economic slump. (Photo by Chamila Karunarathne/EPA/EFE/Rex Features/Shutterstock)

A girl poses in antlers ahead of a curfew on pub in Nottingham, a city in central England’s Midlands region on September 21, 2020 as Freshers' Week got underway. Revellers were also pictured out in Birmingham, which was plunged into a local lockdown amid a surge in coronavirus cases. (Photo by Ashley Kirk/The Sun)

In this image released by World Press Photo, Thursday April 15, 2021, by Ami Vitale for CNN, titled Rescue of Giraffes from Flooding Island, which won the first prize in the Nature Singles category, shows A Rothschild's giraffe (Giraffa camelopardalis rothschildi) is transported to safety in a custom-built barge from a flooded Longicharo Island, Lake Baringo, in western Kenya, on Dec. 3, 2020. (Photo by Ami Vitale for CNN, World Press Photo via AP Photo)

Local folk artists perform next to a police line outside Congress building, as they wait for news from inside on who will be the country's next president, in Lima, Peru, Sunday, November 15, 2020. Interim President Manuel Merino announced his resignation following massive protests unleashed when lawmakers ousted President Martin Vizcarra. (Photo by Rodrigo Abd/AP Photo)