Disposable Vs. Reusable

Coffee Mug

How do you like your coffee?

Leading a more sustainable life makes our daily choices a bit more complex. For instance, when you have a cup of coffee have you thought about what that cup is made from? Choosing a cup seems to be a simple decision, but like good coffee it's a subject that's dark and hard to see through to the bottom.

Evaluating the environmental impact of different coffee cup materials can be done with a life cycle energy analysis. For those who haven't taken an economics class, a life cycle analysis is a way of breaking down the energy and material costs of a product over its usable life. Fortunately, Professor Hocking at the University of Victoria performed a Life Cycle Energy Analysis of foam, paper, glass, plastic and ceramic cups. The first part of the analysis was to determine the embodied energy, or the energy used in the manufacture, of each cup.

Styrofoam cups require the least amount of energy in their manufacture (0.3 Megajoules) and ceramic cups require the most energy (14 Megajoules). This is due primarily to the mass of each cup as ceramic cups have much more mass than a flimsy foam cup. So, if we were to use a coffee cup only once, using a foam cup would be the more energy-conscious choice. But if we reuse a coffee cup, which is uncommon with foam and paper, then glass and ceramic mugs become the better choice. A glass coffee cup breaks even energy-wise with a disposable paper cup after only 15 uses and a ceramic cup breaks even after 39 uses.

Unfortunately, Professor Hocking's life cycle analysis appears to be incomplete. While the study illustrates cup manufacturing and washing energy costs it doesn't take into account that each paper or foam cup must be delivered to the coffee drinker and then disposed of. As well, the life cycle analysis doesn't account for the resource costs of diminishing material resources (the oil to manufacture styrofoam) and landfill space. These costs likely further improve the break-even point for glass and ceramic cups.

All of this is a highly detailed way of saying that reusing a ceramic mug is better for the planet than throwing away a foam or paper cup. That should be obvious, but having proof doesn't hurt. Regarding my coffee, I like it black and I drink it from a mug I've had for years.

Further Reading:

Life Cycle Analysis: Reusable vs. Disposable Cups

Life Cycle Analysis

Embodied Energy