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 man dressed as Santa Claus arrives to distribute toys on children living in an impoverished neighbourhood in Iraq's southern city of Basra on December 26, 2020. (Photo by Hussein Faleh/AFP Photo)

Garbage, including plastic waste, is seen at the beach of Costa del Este, in Panama City, on April 19, 2021. Every two weeks, Marine Biology students descend about five meters in the sea to take care of a coral nursery of the staghorn species (Acropora cervicornis) in Portobelo, Panama, with which they aim to restore reefs damaged by climate change and pollution, as part of the Reef2Reef project. (Photo by Luis Acosta/AFP Photo)

Dancers perform during the Navam Perahera at the Gangaramaya Temple in Colombo, Sri Lanka, on February 15, 2022. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Brush your teeth and get cleaned up for the week ahead! These animals answered the call of good dental hygiene. Here: Hamster holds toothbrush. (Photo by Neo Vision/Getty Images/Amana Images RM)

A Hindu woman worships the Sun god in the waters of a lake during the religious festival of Chhath Puja in Agartala, India, November 13, 2018. (Photo by Jayanta Dey/Reuters)

A picture taken on August 25, 2021 shows a view of the Aletsch Glacier. After hiking for hours across the mountain and a vast expanse of white, Swiss glaciologist Matthias Huss crouches down near the middle of the massive glacier and checks the measurements. Analysis of the data gathered from Aletsch, the largest glacier in the Alps, paints a dire picture of the toll that climate change is taking on the behemoth. (Photo by Fabrice Coffrini/AFP Photo)

Members of the Unidos da Tijuca samba school parade at the “Opening of Carnival 2022” event, at the Cidade do Samba, in Rio de Janeiro, Brazil, 27 February 2022. The event is a preview of the parades of the Samba Schools of the Special Group, postponed to April due to the COVID-19 pandemic in Brazil. (Photo by Andre CoelhoEPA/EFE)