Pilgrims dressed in traditional Bavarian clothes attend the traditional Georgi horse riding procession on Easter Monday in heavy snowfall, in the southern Bavarian town of Traunstein April 6, 2015. Since the early 16th century, farmers have taken part in the pilgrimage to bless their horses. This tradition, the “Georgiritt”, goes back to the legend of Saint George, the horsemen's patron saint. (Photo by Michael Dalder/Reuters)

Sgt. William Olas Bee, a U.S. Marine from the 24th Marine Expeditionary Unit, has a close call after Taliban fighters opened fire near Garmsir in Helmand Province of Afghanistan, May 18, 2008. (Photo by Goran Tomasevic/Reuters)

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)

People walk to the Venezuela Aid Live concert that will play on the Colombian side of the border near the Simon Bolivar International Bridge, from San Antonio del Tachira, Venezuela, Friday, February 22, 2019. (Photo by Rodrigo Abd/AP Photo)

An Iraqi Army member launches a rocket during the operation to retake Mosul from Daesh terrorists in Jadid neighborhood as the clashes between Iraqi Army and Daesh terrorists continue in Mosul, Iraq on April 2, 2017. (Photo by Hemn Baban/Anadolu Agency/Getty Images)

Members of a propaganda troupe perform in a public square in Pyongyang on April 12, 2017. (Photo by Ed Jones/AFP Photo)

A homeless street child looks in the window of a car in Jammu, India, Friday, January 6, 2017. Some 800 million people in the country live in poverty, many of them migrating to big cities in search of a livelihood and often ending up on the streets. (Photo by Channi Anand/AP Photo)

A worker carries a basket of fish, at a wholesale fish market, on the outskirts of Kolkata, March 15, 2017. (Photo by Rupak De Chowdhuri/Reuters)