Your Mug and The Environment

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On Thursday, I posted a link to a "guerrilla" sticker campaign that's drawing attention to the ways we absentmindedly waste paper products. As the day wore on I couldn't stop thinking about another common source of waste in the office: the disposable coffee cup.

image11.pngI used to think that ceramic mugs were automatically ecofriendly, but they're not. The study that I found suggested that you need to reuse a ceramic mug about 500 times to hit the "break even point"--the point where the energy used to make the ceramic mug, divided by the number of uses, equals the energy used to make a single styrofoam cup.

The most recent work that I could find on the issue was a study that compares the energy used to make ceramic, glass, paper and polystyrene (commonly called "styrofoam") cups, written by chemist and professor Martin Hawking. The paper was published in the journal of Environmental Management in 1994, which sounds like a scientific lifetime ago, but my little sister (who studies paper science and engineering at college) said that the field is slow moving and that the numbers could still be relatively accurate. Let me know if you find a newer study or review article.

The study concluded that polystyrene cups take the least energy to make. In fact, it takes more energy to wash your mug than it takes to make a styrofoam cup, according to Hawking's paper. But there's little doubt that the petroleum-based food containers have a bad reputation. Nobody seems to have a particularly cost-effective way of recycling styrofoam, so most of the cups go straight into a landfill. EPA estimates suggest that Americans throw away nearly 25,000,000,000 styrofoam cups each year.  So I understand why the food containers have been banned in a number of U.S. Cities, and I why get dirty looks from hipsters when I get my tall mocha double-cupped at the coffee shop.  

In the end, the ceramic mug comes out as the most eco-friendly choice, but only if you keep using it and maybe even use it more than once between washing.  (I'd suggest rinsing between uses.  Otherwise, it sounds a wee bit gross.)


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4 Comments

i've used crumpled plastic bags to insulate walls, as well as dirty lint from a cotton jin. since the insulating value of crumpled , light materials approaches that of still air which is what most commercial materials are, you could consider collecting your and your colleague's cups, crumpling them and insulating a poorly insulated wall or attic.
i remember the boston area having lots of dwellings like that.

Recycling of styrofoam (and possibly other plastics) for such products as insulation offers a possible business opportunity for the entrepreneurial person, or an ad hoc possibility for others. There are some potential issues. One is the need to clean the styrofoam thoroughly so that the food remnants do not foul the building and draw pests. Food remnants can also decay into methane, which is about 23 times as potent a greenhouse gas as carbon dioxide, so we need to find ways to make constructive use of waste organic matter. I will make a controversial suggestion about organic matter: the methane that is produced from its decay may be sufficiently damaging so that our society should look at subsidizing approaches to reducing its outgassing by recycling waste.

In terms of the insulating properties of styrofoam, we immediately observe that styrofoam for cups was manufactured to produce an insulating layer. There are some more factors for building insulation. I recall watching carpenters stuff glass fibre insulation into corners of walls when I was a boy and fascinated with the construction of buildings. I later came to understand that they did not understand the nature of insulation. Insulation works by having many tiny air pockets from which heat is slow to move to the next air pocket. In any insulative approach you try, it is important to think about whether this is achieved. Are there pathways for air currents to pass through the insulation? Is there a barrier so that wind pressure against a wall will not simply (subtlely or obviously) pass through into the room? Drafts do not have to be apparent to cause serious thermal discomfort. Some insulations provide a useful barrier themselves, and large sheets of TyVek on the outside of walls also reduces this infiltration. You also want to have a vapor barrier so that water vapor does not simply condense in the walls, leading them to rot out.

Careful thought and execution leads to reduced energy usage, increased comfort, and reduced carbon footprint. http://greenenergyglobalwarming.blogspot.com/

@herbissimus, interesting thought. I had the same reaction as John Carlton-Foss in terms of cleaning the cups thoroughly enough.

Long live plastic cups...
As long as your not worried about tires...no need to worry about cups...

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This page contains a single entry by Rachel VanCott published on January 24, 2009 11:56 AM.

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