Afghan children have ice cream during the Afghan New Year (Newroz) celebration in Kabul March 21, 2014. Afghanistan uses the Persian calendar which runs from the vernal equinox. The calendar takes as its start date the time when the Prophet Mohammad moved from Mecca to Medina in 621 AD. The current Persian year is 1393. (Photo by Ahmad Masood/Reuters)

“Thunderstruck”. Summer stom. A super cell formed off the coast of New Zealand, intensified and swept across Christchurch and North Canterbury, February 23, 2014. Photo location: Christchurch, New Zealand. (Photo and caption by David Hardy/National Geographic Photo Contest)

Winner. “I took this picture of a woman in traditional clothing in Cartagena, Colombia”. PAUL GOLDSTEIN, JUDGE: “The blaze of colour from every angle, the boldness of the picture, taken from behind, which gives it so much more allure and frankly a superb get up. Did I mention the colours? Oh, and that looks suspiciously like a Nokia”. (Photo by Stanislav Shmelev/The Guardian)

“Environmental Migrants: The Last Illusion” by photographer Alessandro Grassani, documents the life of people in Kenya, Mongolia and Bangladesh who migrate to escape environmental stresses to the city of their own countries in hopes for a better life. Here: Asia, Mongolia, March 27, 2011. A view of Ulaan Baator over the shoulder of a slumbering drunk. Alcoholism is a huge problem in the city, home to almost half of Mongolia's people. The capital's population has doubled in the past two years. High levels of unemployment and poverty await herders who abandon rural areas and arrive in the city, illiterate and untrained in any skills necessary for urban jobs. (Photo by Alessandro Grassani)

A Pakistani monkey handler Naseer Khan plays flute to attract passers by for a monkey show to earn his living in Islamabad, Pakistan, Monday, September 7, 2015. (Photo by B. K. Bangash/AP Photo)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

Supporters of Ratko Mladic wave flags with his picture and reading in Serbian “Serbian hero” during a rally organized by the ultra nationalist Serbian Radical Party in front of the Parliament building on May 29, 2011 in Belgrade, Serbia. Some 7,000 supporters of the former Bosnian Serb army chief Ratko Mladic, who was arrested on Thursday in a village in Serbia after 16 years on the run, took to the streets of Belgrade, to hear speeches and protest Mladic's arrest. Mladic, who is facing extradition to the The Hague, is accused of war crimes, including the 1995 massacre of 7,500 Muslin men and boys in Srebrenica. (Photo by Srdjan Stevanovic/Getty Images)