Weighing sustainability of real vs. fake Christmas trees

As people contemplate their holiday plans, they may find themselves in an environmental quandary, asking: Which is more sustainable, a real or artificial Christmas tree?

“I think a misconception about sustainability in general is that there are black-and-white decisions where one choice is always better than another choice,” says Lorena Grundy, practice assistant professor in chemical and biomolecular engineering in Penn’s School of Engineering and Applied Science. “There are situations in which a real Christmas tree makes more sense and is more sustainable, and there are situations in which a fake tree makes more sense and is more sustainable. There’s not just one correct answer.”

This is just one way in which Grundy, who also directs the new master’s degree program in energy and sustainability engineering launching next fall, encourages her students to think about how lifecycle assessment and material sustainability apply in their day-to-day lives.

Grundy recently shared with Penn Today a few questions consumers can ask themselves to make a sustainable tree-purchasing decision—while acknowledging the value of other factors, such as the sentimental attachment she feels to the fake tree her parents have had since before she was born.

How long would you keep a fake tree?

Grundy says that using a fake tree for only one year is typically not the most sustainable choice, considering that fake trees are manufactured from metal and plastic and that most trees at big-box stores are shipped several thousand miles from China, adding to the climate impact.

She says the most commonly agreed-upon range of how long someone would need to reuse a fake tree to make the carbon footprint less than that of a real tree is seven to 10 years, though studies vary in their estimates. Still, the longer the better, Grundy says.

How would you dispose of a real tree?

There are multiple environmentally friendly options for disposal of a real tree. “Typically, if you put it out on the curb, it’s going to go to a landfill, where it will then likely decompose and form methane, which is a really potent greenhouse gas,” Grundy says. “Whereas if you use one of the city’s drop-off sites, those trees get recycled.”

She adds that people can also arrange for compost companies to pick up their tree. Another option is to let the Philly Goat Project feed the tree to their goats. And a third eco-friendly possibility is to get a tree that’s potted, so that at the end of the holiday season you can plant it in your backyard—where it will continue absorbing carbon dioxide from the atmosphere.

Where did the tree come from?

“The other thing to consider is transportation,” Grundy says, because getting real trees grown as locally as possible will minimize the environmental impact. “Are you driving your SUV 100 miles to go to a farm to pick your tree, or was it grown next door, or were 100 trees shipped by truck 100 miles together so that the impact of transportation is a lot lower per tree?”

Overall, Grundy thinks about the issue holistically, saying, “There’s not one hard-and-fast way to act sustainably.”