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)

An Afghan man prepares tea for customers at a roadside tea shop on the outskirts of Jalalabad February 2, 2015. (Photo by Reuters/Parwiz)

A Nepalese man sits outside a Hindu temple as a goat rests on a parked scooter in Khokana, Lalitpur District, Nepal, Monday, September 26, 2016. Writing on the wall offers prayers to Hindu god Shiva. (Photo by Niranjan Shrestha/AP Photo)

Spanish soldiers of the 7th Airborne Light Infantry Brigade “Galicia” fire a howitzer Light Gun L118 during maneuvers with other units in preparation to NATO's Very High Readiness Joint Task Force (VJTF) in Zaragoza, Spain, April 19, 2016. (Photo by Javier Cebollada/EPA)

Residents wade through the flood brought by typhoon Vamco in Manila, the Philippines, on November 12, 2020. Typhoon Vamco, the third powerful cyclone to batter the Philippines in 11 days, made landfall on Wednesday night, unleashed fierce winds and intense rains that triggered landslide, rockslide and flash floods. (Photo by Rouelle Umali/Xinhua News Agency)

A couple enjoys the view of the ethnographic and amusement center Kremlin in Izmailovo reflected in the Serebryano-Vinogradnii lake in Moscow, Russia on July 30, 2017. (Photo by Mladen Antonov/AFP Photo)

Clouds in Drakensberg Escarpment in the lowveld, also known as Mariepskop, South Africa in July 2019. Snapped by professional Photographer, Em Gatland, 37, from Greater Kruger, South Africa, the unique shot could easily be mistaken for a dangerous wave rather than clouds passing through a sunset. (Photo by Em Gatland/Caters News Agency)

A labourer packs incense in preparation for Tet, the traditional Vietnamese lunar new year, in Hong Chau village, outside Hanoi January 29, 2015. Tet is from February 14 till 24. (Photo by Reuters/Kham)