David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)

Lali carries balloons to sell on a beach in Mumbai, India, Sunday, October 11, 2015. The United Nations General Assembly marks October 11 as the International Day of the Girl Child, to recognize girls’ rights and the unique challenges girls face around the world. (Photo by Rafiq Maqbool/AP Photo)

Armed forces veteran Frank Simpson at the Portico library being camouflaged by body artist Carolyn Roper in Manchester, UK on May 16, 2016 as part of the #CountThemIn campaign launched on Monday by the Royal British Legion. (Photo by Jon Super/Royal British Legion/PA Wire)

A 40-foot sculpture of the swimmer Rebecca Adlington was unveiled at the Serpentine in London’s Hyde Park on July 25, 2016 to launch a campaign by Kelloggs to encourage the public to support Team GB at the Rio Olympics. (Photo by David Parry/PA Wire/Barcroft Images)

This picture taken on August 4, 2016 shows three orphaned orangutan babies hanging in a tree whilst attending “jungle school” at the International Animal Rescue centre outside the city of Ketapang in West Kalimantan. (Photo by Bay Ismoyo/AFP Photo)

Thai classical dancers perform for Phra Phrom, the Thai interpretation of the Hindu god Brahma, at the Erawan Shrine in Bangkok, Thailand, Friday, September 4, 2015. Thai authorities unveiled the restored centerpiece Friday of the Erawan Shrine, in the latest bid to restore confidence among Bangkok's tourism and business communities almost three weeks after a deadly bombing. (Photo by Sakchai Lalit/AP Photo)

2016 Rio Olympics, Athletics, Women's Heptathlon Javelin Throw, Groups, Olympic Stadium, Rio de Janeiro, Brazil on August 13, 2016. Evelis Aguilar (COL) of Colombia competes in Javelin group A women's heptathlon. (Photo by Dylan Martinez/Reuters)

Labourers walk near trucks loaded with logs, which are trapped on a muddy road, near an unreserved forest in the village of Igbatoro, southwest Nigeria, August 28, 2014. Wood, a form of biomass, is the sole source of energy for hundreds of millions of Africans who lack access to modern sources of power, and logging, both legal and illegal, remains a lucrative business that has contributed to the rapid shrinking of Africa's rainforests and woodlands. (Photo by Akintunde Akinleye/Reuters)