A Holiday Exploration into Life Cycle Assessme


Yesterday I was relaxing with one of my favorite shows, Modern Family.  Their holiday episode featured a scene where father and son team Jay and Manny had set out to find the perfect Christmas tree.  Jay insisted on getting a real tree, while Manny preferred his fake tree, stating that it was the more environmentally friendly choice.

Being an environmentalist, that line made me think.  I can’t imagine Christmas without a real Christmas tree – it just wouldn’t be the same.  But was Manny right?  Maybe the effects of chopping down the carbon sink that now sat in my living room was worse than manufacturing the plastic necessary for a fake tree?  Or maybe the fact that I could use a fake tree for many holiday seasons to come made that the better choice?

If I learned one thing as a grad student, it’s that the “right” answer is almost always: it depends.  But, school also introduced me to Life Cycle Assessment (LCA), a very useful tool for approaching conundrums like this.  LCA is a technique to assess the environmental aspects and potential impacts of a product by examining its entire life cycle from material extraction to disposal. It is often used to compare two products that are substitutes for each other (like paper bags vs. plastic bags) and is useful because it quantifies all of the impacts in a way that allows for an apples-to-apples comparison.  Conducting an LCA is a time consuming, data driven process consisting of four main steps:  goal and scope definition, inventory analysis, impact assessment, and interpretation.  Thankfully an ISO-compliant, third party peer reviewed LCA already exists to answer my question!

The study compares the most popular version of each in terms of share of the United States market.  Each life cycle phase (see Figure 1) is evaluated for the same impact categories (energy demand, global warming potential, air acidification potential, smog potential, and more).  So, which tree wins?  My first hunch was right:  it depends!  Overall, the differences were found to be negligible.  But there were still some interesting takeaways:  if you use an artificial tree, use it for as many years as possible!  And distance driven to get a natural tree makes a big impact… so keep your search close to home.  While I can’t go into more detail than that here, I highly suggest you check out the full LCA here.  It’s a great intro into the LCA process and is so fitting for the season!

Whichever type of tree you choose, the best thing you can do is to live consciously every day and lessen your impact in your daily life… not just during your search for the perfect Christmas tree.  As for me, this year I’m hoping to try out a living Christmas tree. Happy holidays to all!


Leave a Reply

Your email address will not be published. Required fields are marked *