A worker distributes electronic waste at a government managed recycling centre at the township of Guiyu in China's southern Guangdong province June 10, 2015. The town of Guiyu in the economic powerhouse of Guangdong province in China has long been known as one of the world’s largest electronic waste dump sites. At its peak, some 5,000 workshops in the village recycle 15,000 tonnes of waste daily including hard drives, mobile phones, computer screens and computers shipped in from across the world. (Photo by Tyrone Siu/Reuters)

An agent of the OIPR, one of the government agencies charged with managing protected land, stands next to cocoa trees inside Mont Peko National Park in Duekoue department, western Ivory Coast August 18, 2015. (Photo by Luc Gnago/Reuters)

A smokejumper leaps from an airplane during a training flight above Winthrop, Washington, U.S., June 30, 2016. On a 100-degree day in early June, eight experienced firefighters did sit-ups in a semicircle training to parachute into a wildfire. Better known as “rookie candidates”, they were determined to make it through the five-week program at North Cascades Smokejumper Base in Winthrop, Washington, where the first experimental jumps occurred in 1939. (Photo by David Ryder/Reuters)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

Dillon Bracken (L) and Atalya Stachel dance during the Burning Man 2014 “Caravansary” arts and music festival in the Black Rock Desert of Nevada, August 30, 2014. Over 65,000 people from all over the world have gathered at the sold out festival to spend a week in the remote desert cut off from much of the outside world to experience art, music and the unique community that develops. (Photo by Jim Urquhart/Reuters)

Friends of Li Guojun drive a homemade tank-shaped vehicle in Kangping county, China. Li, a farmer who is a fan of tanks, spent six months with help from his friends to construct the almost 20-foot vehicle which weighs 2.5 tons. (Photo by Sheng Li/Reuters)

Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)