A young vendor hawks food on a market in Kara in the state of Ogun, on September 23, 2015. Nigeria imposed tight movement restrictions in the restive northeast after Boko Haram bombings that killed more than 100 raised fears of fresh attacks over the Eid al-Adha festival. The military said the use of all vehicles would be banned throughout Borno state during the Muslim festival, which is known as Sallah in Nigeria and marked with two days' public holiday from Thursday. (Photo by Pius Utomi Ekpei/AFP Photo)

Russian artist Maria Gazanova (L) works on her "The Alive Painting" art work during the Art Krasnoyarsk annual festival in Siberian city of Krasnoyarsk, Russia November 4, 2015. (Photo by Ilya Naymushin/Reuters)

A jockey falls off during a traditional Barapan Kebo or buffalo races, in Taliwang, on the island of Sumbawa, West Nusa Tenggara, Indonesia November 22, 2015. Around 250 pairs of water buffalo took part in the Barapan Kebo ahead of the planting season, for prizes which included a top prize of a pilgrimage to Mecca. (Photo by Sigit Pamungkas/Reuters)

Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

A Chinese man wears a mask to protect against pollution as he waits at a red light while commuting to work in heavy smog on December 8, 2015 in Beijing, China. The Beijing government issued a 'red alert' for the first time since new standards were introduced earlier this year as the city and many parts of northern China were shrouded in heavy pollution. Levels of PM 2.5, considered the most hazardous, crossed 400 units in Beijing, lower than last week, but still nearly 20 times the acceptable standard set by the World Health Organization. The governments of more than 190 countries are meeting in Paris to set targets on reducing carbon emissions in an attempt to forge a new global agreement on climate change. (Photo by Kevin Frayer/Getty Images)

Al-Shamiyah Front fighters inspect a new locally-made cannon named “Borkan” (Volcano) as it was being launched towards forces loyal to Syria's president Bashar Al-Assad located in Aleppo artillery school, March 7, 2015. The “Borkan” is made out of four tubes attached to a loader, which can fire four shells at a time, and have a range of three kilometers (1.86 miles). (Photo by Abdalrhman Ismail/Reuters)

Children play on a donkey cart belonging to an elderly Afghan refugee sleeping on a roadside on the outskirts of Islamabad, Pakistan, Wednesday, February 18, 2015. (Photo by Muhammed Muheisen/AP Photo)