Santa Claus rides in his sleigh as he prepares for Christmas in the Arctic Circle near Rovaniemi, Finland December 15, 2016. At Santa Claus' Lapland home in Finland, his helpers sort out piles of letters from around the world, each detailing children's requests for this Christmas. (Photo by Pawel Kopczynski/Reuters)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

In this photo taken on Tuesday, December 20, 2016, dancers of the U.S. company “Catapult” create a group of ostriches, during their show “Magic Shadows”, in Milan, Italy. Dancers in the company create shadow sculptures with their bodies, giving a contemporary twist to the ancient Chinese art of shadow theaters. (Photo by Luca Bruno/AP Photo)

A surfer drops in on a large wave at Praia do Norte, in Nazare December 11, 2014. Praia do Norte beach has gained popularity with big wave surfers since Hawaiian surfer Garrett McNamara broke a world record for the largest wave surfed here in 2011. (Photo by Rafael Marchante/Reuters)

A woman rolls a marijuana cigarette during the first “Expo Cannabis” fair in Montevideo December 14, 2014. Expo Cannabis offers conferences about different topics such as the medicinal use of cannabis and cultivation techniques as well as displaying hemp goods, cannabis cultivation items and seeds. (Photo by Andres Stapff/Reuters)

Workers polish a snow sculpture ahead of the 16th Harbin Ice and Snow World in Harbin, Heilongjiang province, December 22, 2014. The 16th Harbin Ice and Snow World will be officially opened on January 5, 2015. (Photo by Reuters/Stringer)

A rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

A girl looks from her flooded house on the outskirt of Kota Bharu in Kelantan December 29, 2014. The worst flooding in Malaysia in more than a decade has killed 10 people and forced nearly 160,000 from their homes and more rain is expected, authorities said on Sunday. (Photo by Athit Perawongmetha/Reuters)