Peanut Butter Jars and Life Cycle Analysis

This article was first published in the Skaha Matters Newsletter.

I hate peanut butter jars. You can’t put them in recycling dirty. They have paper labels so they can’t go into the dishwasher. Prepping a peanut butter jar for recycling takes hot water, soap, and elbow grease (and my kids know I loath peanut butter). At some point in the process I usually mutter “Is this really worth it?”. Sometimes I hear it isn’t worth recycling because it costs more than making it from scratch. Or “Glass is made of sand. We have no shortage of sand on the planet so there’s no point in recycling glass”. Are we wasting time, energy water and money recycling glass? Some recycling is worth money -- the value fluctuates but aluminium cans, certain paper products and HDPE are in demand (although at 40 cents per pound, no one is going to break into your garage to get your HDPE). This cash value is easy to find. But when you start comparing recycled materials to new-made materials, you are comparing apples to oranges. Take just transportation. Did you have to dig it out of a mine? Did you have to ship it from a far away country? Are recycled bottles collected on the same continent as the factory? If you start considering questions like this, suddenly recycling may be much more valuable than we thought. In order to make an apples to apples comparison of a new-extracted material to a recycled material you have to follow the stuff from digging it up all the way to discard. This is a life cycle analysis.

Why don’t we evaluate everything by life cycle analysis? First, it takes a lot more work. Some things can be measured directly (think of the electricity bill for the glass-making plant) while others have to be estimated or modeled. Environmental engineers and scientists think of life cycle analysis as constructing a framework, then they work to make the framework more accurate. It is always less precise than measuring. Second, you have to share the assumptions you made. I’m amused by electric vs. paper hand drying war. Electric dryers win if you assume people use 2+ towels to dry their hands. Recycled paper towels win if you assume that electricity comes from a carbon source.

So what is the answer for glass? In a life cycle analysis, recycled glass generates half the carbon virgin-source glass does. With this useful information to back me, from now on glass peanut butter jars will be prepped for recycling -- by the people who eat peanut butter. I’ll accept responsibility for the jar that held martini olives.

Thanks to Jeffrey Morris of Sound Resource Management.


Articles on Teaspoon Energy by Kristy Dyer are licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License You can reprint it for free, as-is.