Christmas Tree Footprint Calculator

The environmental comparison of a real against an artificial Christmas tree is an amortisation problem rather than a materials problem. A cut natural tree of about 2 m carries roughly 3.5 kg CO2e if it is chipped, composted or burned at end of life, but around 16 kg CO2e if it goes to landfill, because anaerobic decomposition converts part of its carbon to methane rather than CO2. An artificial tree of similar size carries roughly 40 kg CO2e, dominated by PVC production, steel framing and container shipping, and that burden is incurred once. Dividing the artificial tree's total by the number of years it is kept gives its annual figure, so break-even against buying a fresh tree each season typically falls somewhere between 7 and 12 years of reuse. Two inputs are usually larger than people expect. Transport matters because the trip is short but the payload is a single tree: a 20 km round trip by car at about 0.21 kg CO2e per km adds roughly 4 kg CO2e, the same order as the tree itself. Lighting frequently dominates the total. A string of 400 incandescent mini-lights draws around 160 W, so six hours a day for 30 days consumes about 29 kWh and emits some 11 to 12 kg CO2e at a grid intensity of 0.4 kg per kWh, whereas an LED equivalent draws roughly a tenth of that. The carbon absorbed during a plantation tree's growth is only partially creditable, since the land is replanted and the stored carbon is released again at disposal.

Decorated evergreens moved from a regional German custom into mainstream European practice during the sixteenth and seventeenth centuries, and the tradition reached Britain through the Hanoverian court before an 1848 illustration in the Illustrated London News depicting Queen Victoria and Prince Albert around a tree made it fashionable across the English-speaking world. Commercial supply followed quickly. The woodsman Mark Carr is generally credited with opening the first retail Christmas tree lot in New York in 1851. Electric tree lighting dates to 1882, when Edward H. Johnson, a colleague of Thomas Edison, wired a tree at his Manhattan home with hand-blown coloured bulbs. Artificial trees appeared in the 1930s, when the Addis Brush Company in the United States adapted its toilet-brush machinery to produce bristle trees, and reached a design peak with the aluminium trees manufactured by the Aluminum Specialty Company of Manitowoc, Wisconsin, from 1959. PVC needle construction, largely manufactured in Asia, became the dominant format from the 1980s onward. Carbon accounting for the seasonal choice is recent by comparison. A 2009 life cycle assessment by the Montreal consultancy Ellipsos compared natural and artificial trees over their full life cycles and concluded that an artificial tree had to be kept roughly twenty years to be preferable, and the UK Carbon Trust later published the disposal-dependent figures for natural trees that made landfill avoidance the headline recommendation.