A Tibetan rider fires his weapon as he perfoms his riding skills at the Qinghai Yushu Horse Racing Festival on July 27, 2007 in Yushu County of Yushu Tibetan Autonomous Prefecture, Qinghai Province, northwest China. The Horse Racing Festival of Tibetan nomads in Yushu Prefecture falls in late July and early August on the Tibetan calendar. During the festival, various equestrian skills will be performed along with singing, dancing and costume shows. (Photo by China Photos/Getty Images)

Brush and trees are engulfed in flames after firefighters set a backburn along Highway 191 in an attempt to control a raging wildfire on June 10, 2011 in Nutrioso, Arizona. The fire, which is five percent contained, has so far consumed over 400,000 acres of land and destroyed 29 homes. (Photo by Kevork Djansezian/Getty Images)

Thai residents party after sunset in the water on a flooded street along the swollen Yom river August 24, 2011 Phinchit, Thailand. The death toll has climbed to over 37 as 13 provinces remain flooded with 1.5 million affected. In Phinchit 110,000 people's homes have been flooded by nearby overflowing rivers. (Photo by Paula Bronstein /Getty Images)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)

This Thursday, January 22, 2015 photo made with a long exposure shows the glow from a Noctiluca scintillans algal bloom along the seashore in Hong Kong. The luminescence, also called Sea Sparkle, is triggered by farm pollution that can be devastating to marine life and local fisheries, according to University of Georgia oceanographer Samantha Joye. Noctiluca itself does not produce neurotoxins like other similar organisms do. But its role as both prey and predator tends can eventually magnify the accumulation of toxins in the food chain, according to R. Eugene Turner at Louisiana State University. (Photo by Kin Cheung/AP Photo)

Journalists (L) walk along the new Caminito del Rey (The King's Little Pathway) in El Chorro-Alora, near Malaga, southern Spain March 15, 2015. Dubbed by many media outlets as the world's scariest pathway, the three-kilometre long pathway, which was built at about 100 metres (330 ft) above the gorge of Los Gaitanes between the years of 1901 and 1905, was closed in 2001 after five people died. A new walkway has then been built over the old walkway and will open to the public on March 28, 2015. (Photo by Jon Nazca/Reuters)

Climbers “painted” the Matterhorn red this week to celebrate a special anniversary. A group of mountaineers left red beacons along the route of the famous climb, which is one of the highest mountains in the Alps, and as nightfall came the imposing mountain came alive with colour. The event was organised by clothing brand Mammut to celebrate the 150th anniversary of the first explorers to scale the mountain. (Photo by MSN UK/Mammut)