Performers of Everland Amusement Park present the part of Christmas Fantasy in downtown of Myundong in Seoul, South Korea on December 3, 2019. (Photo by Seokyong Lee/Penta Press/Rex Features/Shutterstock)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

This handout picture taken and released by Thai Royal Household Bureau on December 12, 2019 shows Thailand's Princess Bajrakitiyabha (L) and Princess Sirivannavari sit in their barge during the Royal Barge procession in Bangkok. The Royal barge procession is the final event of the coronation of Thailand’s King Maha Vajiralongkorn. (Photo by Thai Royal Household Bureau via AFP Photo/Handout)

Female activists perform a choreography originated in Chile, and inspired by the Chilean feminist group Las Tesis, to protest against gender violence and patriarchy in front of the Greek parliament at Athens' Syntagma Square on December 22, 2019. (Photo by Louisa Gouliamaki/AFP Photo)

Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

A child walks to an installation made from fallen leaves by college students, in shape of a sofa, to call for people's attention to environment protection, in Hangzhou, Zhejiang province, China, December 6, 2016. (Photo by Reuters/China Daily)

Russian artist Maria Gasanova adjusts her make-up as she finishes “The Siberian Beauty” body art work from her “The Alive Painting” series before the opening ceremony of the Cultural Universiade as part of preparation for the 2019 Winter Universiade Krasnoyarsk, in the Siberian city of Krasnoyarsk, Russia, December 9, 2016. (Photo by Ilya Naymushin/Reuters)

Alpine Skiing, FIS Alpine Skiing World Cup, Men's Parallel Giant Slalom, Alta Badia, Italy on December 19, 2016. Hostesses take a bath in a Jacuzzi pool during the race. (Photo by Stefano Rellandini/Reuters)