World Climate Day
World Climate Day is held on December 8. Initiated by several environmental associations of France and Belgium. This event in the first decade of the month december is annual.
International Sweater Vestival on December 6 (Festival of Sweater Vests - fun unofficial Christmas fashion-related holiday featured);
World Techno Day on December 9 (Juan Atkins was born on Dec 9, 1962, and was part of the Belleville Three, so named because of their time together in Belleville, Michigan);
National Tree Planting Day in Malawi on December 14 (Date for 2020; celebrated on the second Monday in December);