And then, of course, there is the question of whether simply to opt for an artificial tree. These take hundreds of years to break down in landfill, but could be lower carbon overall than buying multiple real trees if reused for long enough. The Carbon Trust estimates the carbon footprint of plastic Christmas trees at around seven to 20 times that of real tree, depending on a range of factors such as whether the real tree went to landfill or how far people travelled to pick it up. If you have an artificial tree, the key is to reuse it for as many years as possible, says Kazar.