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 boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

Ukrainians jump over a bonfire in Kiev, Ukraine, 06 July 2019, as they celebrate the traditional pagan holiday of Ivana Kupala. Ivana Kupala is celebrated, during the summer solstice, on the shortest night of the year, marking the beginning of summer and is celebrated in Ukraine, Belarus, Poland and Russia. People sing and dance around bonfires, play games and perform traditional rituals. Young people jump over bonfires in order to test their bravery. Couples holding hands jump over the flames to test their love. If the couple does not succeed it is predicted to split up. Traditionally, children and young unmarried women wear wreaths of wild flowers on their heads to symbolize purity. (Photo by Sergey Dolzhenko/EPA/EFE)

Indian bride takes part in a mass marriage ceremony under chief minister's welfare scheme (Mukhyamantri Kanyadan Yojna) on the occasion of the Basant Panchami festival, in Bhopal, India, 30 January 2020. (Photo by Sanjeev Gupta/EPA/EFE/Rex Features/Shutterstock)

Protesters wear gas masks in the front of the Romanian Environment Ministry in Bucharest March 4, 2019, to demand better air. Dozens of people holding placards reading “Our children don't breath air anymore” gather in the front of the Environment Ministry to ask for better breathable air in Bucharest. (Photo by Daniel Mihailescu/AFP Photo)

Peng Jing, 24, attends her wedding photography shoot after the lockdown was lifted in Wuhan, capital of Hubei province and China's epicentre of the novel coronavirus disease (COVID-19) outbreak, April 15, 2020. (Photo by Aly Song/Reuters)

Medical staff react outside Queen Elizabeth Hospital during the Clap for our Carers campaign in support of the NHS, as the spread of the coronavirus disease (COVID-19) continues, in Birmingham, Britain, April 23, 2020. (Photo by Carl Recine/Reuters)

A man dressed in Andean attire as “Ukukus” or “Pabluchas”, a traditional character that acts as a vigilante imposing social order, uses a whip as a threat to force people to maintain their distance and remind them to wear face masks and gloves as a preventive measure against the novel coronavirus COVID-19, in the Vinocanchon market area in San Jeronimo district, close to the Peruvian Andean city of Cusco, on May 2, 2020. The government has identified public markets as major hotspots of the new coronavirus in Peru, where 40,459 confirmed cases and 1,124 deaths were reported on May 1. (Photo by Jose Carlos Angulo/AFP Photo)