This Tool Calculates the Carbon Footprint of Your Christmas Tree

Which is greener—a real or an artificial tree? It's a question that has vexed Treehugger since we started hugging. We have consistently come down on the side of the real tree, although faux fans claim that if you keep it long enough, an artificial tree will eventually come out ahead. A decade ago, our writer Pablo Paster said that much depends on how far you drive to get the tree, and we can't all live in a forest like Senior Editor Katherine Martinko's family and walk out the door to find one.

So what is the carbon footprint of a tree and how do you calculate it? Thankfully, there is a calculator from Poland-based Omni Calculator that lets you figure it out.

We've covered Omni Calculator's other projects before: they have a calculator for meat and, really, toilet paper. The company says it is made up of a group of "top-class specialists and academics" that "can build calculators for even the most surprising topics."

The latest from cognitive scientist Maria Kluziak and researcher Jack Bowater is a tool that compares the carbon footprint of a real versus a plastic Christmas tree. It considers how much you could reduce your footprint depending on the disposal method or by building zero-waste trees using everyday items, such as books.

Kluziak tells Treehugger: "My Christmas Tree Footprint Calculator shows you the CO2 footprint of various tree options – natural, plastic, or any of 5 zero-waste alternatives (trees made from books, cans, cardboard, plants, even gravity). If you still opt for a natural tree, in the end, the tool also shows how much CO2 you'll save by disposing of it better—like donating it as a snack for elephants ;)"

I was not certain what she meant about book trees, but it is exactly what it sounds like, a tree made of books. We have described them on Treehugger before.

According to a statement, "Maria Kluziak graduated from Jagiellonian University in Krakow with a master’s degree in Cognitive Science. She enjoys breaking down big scientific concepts into bite-sized pieces that anyone can understand, no matter their background. As an avid hiker and dog lover, she created the Christmas Tree Footprint Calculator to influence others to have a green Christmas." So let's see how it works.

You plug in the size of the tree (ours touched the ceiling) and we drove our Subaru the very short distance to the tree store. We note how it will end up, and it punches out a number, 3.171 kilograms. There are drop-downs for miles as well as meters.

But Kluziak doesn't stop there! She then gives us the data if we decide to forgo the tree and build our own out of books and provides a tutorial for building a book tree. Even we serious treehuggers don't go that far.

Another drop-down in the alternative section is a PVC plastic tree, which she calculates will produce 29.394 kilograms of CO2 and will have to be used for 11 years to be better than a real tree. Though as Treehugger's Matthew Hickman noted, there are other reasons to avoid plastic trees, including phthalates and possibly lead. Hickman likes real trees, concluding that "they support American agriculture instead of Chinese industrialism, and they won't knock a few points off of Junior's IQ if he sniffs one."

Playing with the toggles, it appears that what you do with the tree after Christmas is a very big deal. Ours will get mulched by the city as there are no local elephants—yes, that is apparently an alternative, but if it gets landfilled, the emissions go put to 19 kilograms.

There is no dropdown for e-cargo bikes, which is how my daughter's family got their tree home, but miles traveled in a gasoline-powered car is a major variable. Hickman tells us that 23% of Americans buy their trees at cut-your-own tree farms, so it is likely that those mileage numbers will add up.

Kluziak makes a persuasive case for a book tree and has many other suggestions on the calculator site. It won't make any difference in our house; my wife has decorations from her great-grandmother that she thinks are 120 years old and she is going to put them on a traditional tree.

In any case, we are lucky enough to live 500 yards from a tree pop-up in the parking lot that raises money for the homeless, in a city that mulches the trees, so the 3.1 kilograms of emissions from our tree are significantly less than that of a cheeseburger. Next year I will borrow the cargo bike and try to make our tree almost completely carbon-free.