Tuesday, March 23, 2010

Another Reason to Love that Old Mug

There is nothing like sipping your morning coffee from a favorite old mug. And if you need another reason to skip that disposable cup...just "AskPablo"

"I chose styrofoam, ceramic, and stainless steel for my original comparison and looked at the material intensity and the greenhouse gas (GHG) intensity of each, taking into account the fact that one was disposable and the others were reusable. My conclusion was that the production of styrofoam cups has a much lower environmental impact than the other two in terms of resource extraction and GHG emissions. But, since the styrofoam cups are disposable you need a new one every time you have a cup of coffee. The environmental impact then adds up until, at 46 uses, the ceramic mug becomes the environmentally responsible choice. And after 369 uses, the stainless steel mug also become a better choice than styrofoam. Ultimately the ceramic mug is the best choice since it is infinitely reusable and has a lower impact than the stainless steel mug (Although you could factor in the convenience and portability of a stainless steel mug with a lid).

Now, to look at paper cups… Let’s assume that a paper cup is used only once, weighs 20 g, and is made from bleached virgin wood pulp domestically. The material intensity factor for this material is 11.73 g per g of paper so the material intensity of our paper cup is 234.6 g. Using this new number along with the previous results I created a chart that shows the fixed impact of the reusable cups and the variable impact of the reusable cups (the x-axis represents the number of uses and the y-axis represents the material intensity in grams). This shows that styrofoam has a lower material intensity than ceramic until 46 cups and that 24 paper cups are equivalent in material intensity to a stainless steel mug.

If you want the full study and graphs, click this link http://www.triplepundit.com/2007/12/askpablo-disposable-cups-vs-reusable-mugs/

Then think of the impact when you are choosing china vs. disposable for your next meal function!


Anonymous said...

Nice calculations. you should also consider the toxicity of materials. Styrofoam produces harmful substances when created and disposed.

My solution - just stick your head directly under the tap of the expresso machine. Eliminate cups totally and you get hot fresh coffee:)

Nancy J. Zavada, CMP said...

I took your advice, but my head wouldn't quite fit under the espresso press. I was a little concerned about that steam pipe too!