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 knight parades in the street during the traditional carnival parade in Cologne, western Germany, Monday, February 16, 2015. (Photo by Martin Meissner/AP Photo)

A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)

Members of the Indian Army display aerobatic Taekwondo skills during the 11th Reunion and 262nd Anniversary of Army Service Crops in Bangalore, India, 09 December 2022. The 11th ASC Reunion & 262nd Corps Day will be held at Army Service Corps (ASC) Centre & College on 8th and 9th of December 2022, to showcase the military capabilities. Indian Army Service Corps, established in 1760, is an arm of the Indian Army handling logistic support. (Photo by Jagadeesh N.V./EPA/EFE/Rex Features/Shutterstock)

Britain's Health and Social Care Secretary Matt Hancock wears Union Jack socks as he leaves with Britain's Leader of the House of Lords Baroness Evans after a cabinet meeting on Downing Street in London, Britain on January 7, 2020. (Photo by Toby Melville/Reuters)

Indian girls in traditional attire pose for photographs as they practice the Garba, the traditional dance of Gujarat state, ahead of Navratri festival in Ahmadabad, India, Saturday, October 3, 2015. Navratri or nine night festival will begin on October 13. (Photo by Ajit Solanki/AP Photo)

Elephants munch on Christmas trees in their enclosure at Berlin's Zoologischer Garten Zoo on January 4, 2013 in Berlin, Germany. Traditionally, the animals get in the first week of the year leftover Christmas trees. (Photo by Andreas Rentz)

Commonwealth dance group on the right track with Virgin Trains – Photo call at Glasgow Central Station. (Photo by Daily Record)