A sign marks a railway crossing next to the troubled Kruemmel nuclear power plant on June 2, 2011 in Geesthacht, Germany. The German government recently announced it will phase out the country's 17 remaining nuclear reactors by 2022 in a policy initiative that represents a radical reversal from its previous policy and was sparked by the disaster at Fukushima. Kruemmel went into operation in 1983 but was taken offline following a fire in 2007. (Photo by Sean Gallup/Getty Images)

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)

Boat crew members train on the waters of the Tonle Sap River on the morning of the first day of the Water Festival on November 13, 2016 in Phnom Penh, Cambodia. The yearly three-day Water Festival is one of the most important holidays in Cambodia and celebrates the end of the rainy season and the start of the rice harvesting. The Festival also coincides with the Tonle Sap river reversing course, which it does twice a year. Approximately 2 million people are expected to attend this year's festival, during which 259 boats and nearly 20,000 oarsmen will participate in the races. After a fatal stampede resulting in the death of some 353 people during the Water Festival in 2010, it has been cancelled four times over the past five years, with weather used as an official excuse. (Photo by Omar Havana/Getty Images)

“A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy”. – Wikipedia

Photo: A “Double Eagle” gold twenty dollar coin is displayed above a catalogue picture showing the reverse side of the coin at Goldsmith's Hall on March 2, 2012 in London, England. Nearly half a million of these coins were originally minted in the midst of the Great Depression in the US. Only 13 are known today after the rest were melted down before they ever left the US Mint, sacrificed as part of a strategy to stabalise the American economy. In 2002 a Double Eagle sold at auction for $7.6 million. (Photo by Peter Macdiarmid/Getty Images)

Venezuela's food shortages, inflation and crumbling medical sector have become such a source of anguish that a growing number of young women are reluctantly opting for sterilizations rather than face the hardship of pregnancy and child-rearing. Traditional contraceptives like condoms or birth control pills have virtually vanished from store shelves, pushing women towards the hard-to-reverse surgery. While no recent national statistics on sterilizations are available, doctors and health workers say demand for the procedure is growing. (Photo by Carlos Garcia Rawlins/Reuters)

Lukas Podolski of Koeln is challenged by Philipp Wollscheid of Nuernberg during the Bundesliga match between 1. FC Koeln and 1. FC Nuernberg at RheinEnergieStadion on April 3, 2011 in Cologne, Germany.