Iraqi Kurdish refugees wait with children in Cukurca refugee camp in Turkey April 8, 1991. Reuters photographers have chronicled Kurdish refugee crises over the years. In 1991 Srdjan Zivulovic documented refugees in Cukurca who had escaped a military operation by Saddam Hussein's government in Iraq aimed at “Arabising” Kurdish areas in the north. Hundreds of thousands fled into Turkey and Iran. Images shot in recent months show familiar scenes as crowds of people flee Islamic State militants in Syria. There are as many as 30 million Kurds, spread through Turkey, Iraq, Syria and Iran. Most Kurds are Sunni Muslims, but tend to feel more loyalty to their Kurdishness, rather than their religion. (Photo by Srdjan Zivulovic/Reuters)

A Grey Seal pup and it's mother lay in the mud at the Lincolnshire Wildlife Trust's Donna Nook nature reserve on November 24, 2014 in Grimsby, England. Seal pup numbers have increased on last year with over 800 pups born at the reserve so far. Large bull seals are the first to arrive at the reserve in late October or early November where they will wait for females. (Photo by Dan Kitwood/Getty Images)

A participant takes part in the Bristol Park and Slide project, an interactive temporary installation by artist Luke Jerram set up in Park Street in the centre of Bristol, southwest England on May 4, 2014. Over 95,000 people applied for just 360 tickets to slide on inflatable lilos down a lubricated water slide in a town centre street. (Photo by Leon Neal/AFP Photo)

On August 31, 2012, a long filament of solar material that had been hovering in the sun's atmosphere, the corona, erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. The CME did not travel directly toward Earth, but did connect with Earth's magnetic environment, or magnetosphere, causing aurora to appear on the night of Monday, September 3. (Photo by NASA/GSFC/SDO via The Atlantic)

Members of Brazil's Movimento dos Sem-Teto (Roofless Movement) stand in the hallway of one of the 11 empty buildings that the movement took over recently, in the centre of Sao Paulo, November 6, 2012. According to City Hall, there are some 400,000 people in need of stable housing, including the 4,000 families of the Roofless Movement who are squatting in abandoned or vacant buildings that range from apartment blocks to hotels, in Sao Paulo, the largest city in South America. (Photo by Nacho Doce/Reuters)

Cars pass a tank position close to the Russian border near the Ukrainian city of Kharkiv March 24, 2014. U.S. President Barack Obama sought support from European allies and China on Monday to isolate Russia over its seizure of Crimea, and Ukraine told its remaining troops to leave the region after Russian forces overran one of Kiev's last bases there. (Photo by Dmitry Neymyrok/Reuters)

This composite image shows a sequence, from bottom left to top left, of the moon's transition during a total lunar eclipse on April 15, 2014 in Miami, Florida. People in most of north and south America should be able to witness this year's first total lunar eclipse, which will cause a “blood moon” and is the first of four in a rare Tetrad of eclipses over the next two years. (Photo by Joe Raedle/Getty Images)