Labourers load a three-wheeled vehicle onto the back of a van at the Mercato market in Addis Ababa October 9, 2015. Addis Ababa's “Mercato” – Italian for “market” – is reputedly the biggest open-air market in Africa, lying in the west of the capital. (Photo by Tiksa Negeri/Reuters)

A woman wearing a kimono performs an uchimizu ritual outside a pachinko game parlor in Tokyo June 30, 2015. The splashing of water onto the hot asphalt in summer is an old Japanese tradition meant to cool down the air as the water evaporates. (Photo by Thomas Peter/Reuters)

Houthi followers perform the traditional Baraa dance ahead of a demonstration against the Saudi-led air strikes in Yemen's capital Sanaa August 24, 2015. The nothern-based Houthis, a Shi'ite Muslim group, took control of Sanaa last September. Arab countries intervened in the conflict in March to halt a Houthi advance into the south which caused the Saudi-backed government to flee to Riyadh from its refuge in the southern port of Aden. (Photo by Khaled Abdullah/Reuters)

In this April 16, 2015 photo, costume jewelry is on display for sale at al-Aqeeliya open-air auction market in Riyadh, Saudi Arabia. A man came with the suitcase full of beaded jewelry and sold the whole bag to the auction winner, who had just a few moments to inspect its contents before buying. (Photo by Hasan Jamali/AP Photo)

Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

In this December 22, 2015, photo, Rayani Air flight crews prays before departure at Kuala Lumpur International Airport 2 in Sepang, Malaysia. Malaysia's Rayani Air took to the skies over the weekend with a clear bailiwick. It is the country's first Islamic airline, offering flights that adhere to Islamic rules including prayers, no-alcohol, no-pork meals, and a strict dress code for Muslim female flight attendants. (Photo by Joshua Paul/AP Photo)

A photographer takes pictures near an inflated Master Yoda character hot air balloon during the 33rd annual QuickChek New Jersey Festival of Ballooning at Solberg Airport Friday, July 24, 2015, in Readington, N.J. The festival which runs through Sunday, July 26, 2015, will feature as many as 100 balloons, including many large, shaped balloons of Darth Vader, an American Flag, a giant whale, a Panda Bear, and a baby dinosaur. (Photo by Mel Evans/AP Photo)

Swans swim over a lake, with the air temperature at about minus 35 degrees Celsius (minus 31 degrees Fahrenheit) as steam ascends above the water during sunset near the village of Urozhainy, Sovetsky district of Altai region, January 26, 2015. About 600 swans annually migrate to the lake, which is heated by warm springs, where they spend their winter being fed by yagers, which helps them to survive the severe cold. (Photo by Andrei Kasprishin/Reuters)