Soldiers from 12 Mechanized Brigade perform a simulated casualty evacuation at the Ministry of Defence training area at Copehill Down on Salisbury Plain on March 9, 2012 in Wiltshire, England. The Defence Secretary Philip Hammond visited the military facility to meet soldiers from the Brigade who are shortly to deploy to Afghanistan for Operation Herrick 16, and troops from the 3rd Battalion, the Yorkshire regiment which lost five of the six men who died this week in the deadliest single attack in Afghanistan since 2001. (Photo by Matt Cardy/Getty Images)

City buildings stand beyond the giant excavated hole left by the Mir mine, a former open pit diamond mine, in Mirny, Russia, on Tuesday, November 12, 2013. OAO Alrosa, the world's largest diamond producer, raised about $1.3 billion in an oversubscribed share sale from investors including Oppenheimer Funds Inc. and Lazard Ltd.'s asset-management unit, First Deputy Prime Minister Igor Shuvalov said. (Photo by Andrey Rudakov/Bloomberg)

In a 200-acre-plus dump 5 kilometers north of Haiti’s capital, Port-au-Prince, hundreds of men, women and children scavenge day and night through the burning wasteland. They earn $12 to $15 a day – on a good day – for recycling plastics as well as clothing, household items and aluminum (for smelting). Some 5,000 tons of waste is created each day in the Port-au-Prince area. (Photo and caption by Giles Clarke/Getty Images Reportage)

A volunteer pets a tiger inside a cage at the Wat Pa Luang Ta Bua, otherwise known as Tiger Temple, in Kanchanaburi province February 12, 2015. Thai officials last week raided the Buddhist temple that is home to more than 100 tigers and are currently conducting an investigation into suspected links to wildlife trafficking. Authorities from Thailand's Department of National Parks, Wildlife and Plant Conservation on Thursday checked 143 Bengal tigers living at the temple, and found them to be in good health. (Photo by Athit Perawongmetha/Reuters)

A sign advising to pray for rain hangs above an exhibit area at the 47th Annual World Ag Expo in Tulare, February 12, 2014. About a hundred years ago, when urban water systems were being developed throughout the state, the city of Sacramento wrote protections from metering into its charter, vowing that residents would always have the right to use as much water as they needed. But on Tuesday, the state's top water regulators released a framework for enforcing California's first statewide mandatory restrictions on urban water use – cuts of 25 percent for non-agricultural users ordered last week by Democratic Governor Jerry Brown as a devastating drought enters its fourth year. (Photo by David McNew/Reuters)

A student of the Krasnoyarsk choreographic college prepares backstage before a dress rehearsal of a performance by graduates of the college at the State Theatre of Opera and Ballet in Russia's Siberian city of Krasnoyarsk, Russia, May 12, 2015. The annual performance showcases the work of students from across Russia who study or have studied at the well-known school. (Photo by Ilya Naymushin/Reuters)

Participants in traditional dress ride on horseback as they enjoy the atmosphere at the Feria de Abril (April's Fair) on April 12, 2016 in Seville, Spain. The Feria de Abril has a history that dates back to 1857 and takes place a fortnight after Easter each year. The origin of the fair was a cattle market but the event quickly turned its goal from commerce to having fun. More than 1 million local and international participants are expected to attend the Feria de Abril. (Photo by David Ramos/Getty Images)

An area of vegetation can be seen amongst drought effected farmland in South Australia, November 12, 2015. A pioneering Australian scheme to improve the management of water in the world's driest inhabited continent is facing its first real test as an intensifying El Nino threatens crops and builds tensions between farmers and environmentalists. An El Nino, a warming of sea-surface temperatures in the Pacific, is already causing drought and other extreme weather, affecting millions of people across parts of the world, and experts warn that the intensifying weather pattern could emerge as one of the strongest on record. (Photo by David Gray/Reuters)