Since we go away for a full week over the Christmas holidays we don't have our own Christmas tree.
The German tradition is to get a (real) tree just a few days before or on the day of Christmas Eve and decorate it in the afternoon. Approximately 25 million German living rooms will have a Christmas tree this year. (*1)
The tradition of placing an evergreen inside the house and decorating at Christmastime goes back to 1597 in Bremen, Germany. Nonetheless, for centuries, it was only something which rich people could afford. Starting in the 19th century, more evergreen forests were planted in Europe, thus making it more affordable for every family to have their own tree in their own house. (*1)
Did you know that the Catholic Church in Germany only officially started allowing Christmas trees around the middle of the 20th century? They were against this tradition because of its "heathen" heritage. (*1)
Perhaps it'll be the "Fridays for Future" climate activists who will be prohibiting Christmas trees in the future. The best thing for the environment is to keep the 25 million trees alive and "breathing". Nonetheless even after they are cut down, real trees have a better environmental score than artifical ones.
The British consulting company Carbon Trust estimates that approx. 40 kilograms of CO2 result from the production of one 2-meter tall plastic Christmas tree. In addition, it takes centuries for a plastic tree to decompose whereas a real tree can be burnt after use and only releases 3.5 kg of CO2 in the process. (*2 )
Sources: (in German language, use a translation tool)