Participants wear traditional clogs as shepherds lead their sheep through the center of Madrid, October 28, 2012. (Photo by Andres Kudacki/Associated Press)

A Black Pete interacts with children during the arrival of Sinterklaas, or Saint Nicholas, in Maassluis, Netherlands, Saturday, November 12, 2016. Sinterklaas and his helper Black Pete are at the center of a long-time controversy because Pete is often played by white people in blackface makeup. (Photo by Peter Dejong/AP Photo)

Performers dressed as Ded Moroz, the equivalent of Santa Claus, and his granddaughter Snegurochka (Snow Maiden) take on shoe covers as they visit the Republican Scientific and Practical Centre of Pediatric Surgery in Minsk, Belarus, December 28, 2016. (Photo by Vasily Fedosenko/Reuters)

A performer is seen floating in mid-air as he holds onto a moving bus during the International Magic Festival in Luoyang, Henan province, China September 11, 2016. (Photo by Reuters/China Daily)

A woman plays around as she walks across a glass-bottomed suspension bridge in a scenic zone in Pingjiang county in southern China's Hunan province Thursday, September 24, 2015. The bridge, 300 meters (984 feet) long and 180 meters (590 feet), opened to visitors on Thursday for the first time since its conversion from a regular suspension bridge was completed. (Photo by Chinatopix Via AP Photo)

Models smoke during a break at Sevilla de Boda (Seville Wedding) fashion show in the Andalusian capital of Seville November 27, 2015. (Photo by Marcelo del Pozo/Reuters)

NASA's DHC-3 Otter plane flies in Operation IceBridge-Alaska surveys of mountain glaciers in Alaska in this image released on September 18, 2014. Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. (Photo by Chris Larsen/Reuters/NASA/University of Alaska-Fairbanks)

Models prepare backstage before a presentation as part of Fashion Weekend Plus Size Summer 2015 collection show in Sao Paulo, July 25, 2015. (Photo by Nacho Doce/Reuters)