All environmentally-minded folks are on the lookout for ways to help slow global warming and employ the three R’s into as much of their lives as possible. Unfortunately, in the environment as in life, things can be more complex than we originally think. So when my kids’ school announced an eco-lunch campaign, I was expecting, and received, information about using reusable plastic containers instead of cling wrap and sandwich bags, and a thermos or plastic bottle instead of juice boxes. I used to accept the veracity of the claim that these were good ideas to reduce waste and global warming. My wife, who has a tendency to examine all aspects of a question, the meaning behind the question itself, and other details that routinely escape my notice, asked a seemingly innocent question: is it really more ecologically sound to pack a lunch this way? Of course, I replied. How come, she asked? I don’t know, I replied. On the surface, it just seems intuitive that reusable must be better for the planet than disposable. But why?

Then I read an article in the _New Yorker_ called, “Big Foot” by Michael Specter, which discussed the complexity behind the issues of measuring carbon emissions. First Specter calls for the equality of importance of all forms of carbon consumption in our lives, like food, transportation, clothes, housing, and so on. For example, the average North American feels good about recycling, but is she equally willing to forego air travel? In a critical look at the localvore movement, also known as the “hundred mile diet”, Specter asserts that it is naïve to buy into the notion that consuming locally grown produce is innately more energy efficient than shipped produce. Essentially he argues that local product A grown slowly down the street on nutritionally depleated soil, with low crop yields, picked by hand, can use more carbon than imported product B grown quickly overseas on densely cultivated lots, with high yields, picked efficiently by machine. Specters point is that consuming locally grown is beneficial, but not with all crops and not under all circumstances. For example, one study found that due to the difference in carbon use between transportation by sea (barge) from and land (truck) a New York wine drinker is “greener” by consuming imported French wine than California varieties.

In the end how do we measure the environmental impact of reusable products versus disposable ones? Ask Pablo, a blog about “making sustainability metrics fun” calculated that a coffee or tea drinker using a stainless steel mug will have to reuse it 327 times before it has less of an environmental impact than a disposable Styrofoam cup. For years I have used a reusable steel coffee mug, and have broken, lost and replaced it a few times. Of the four mugs I have gone through over the years, I might be close to break even, but it got me thinking. If you pack your lunch with reusable containers, how many uses would it take to equal the environmental impact of using cling wrap, snack and sandwich bags? The calculation would need to take into account the energy used in manufacture and shipping of the containers, the amount of water and energy used for cleaning the reusable containers, the land-use of its place in the land-fill site (where both zip loc bags and reusable Tupperware eventually end up), and the number of times each container is actually used

The point at which the reusable containers really become more environmentally friendly, or the “eco over/under”, is an elusive figure, but it would be interesting to know if it was five, fifty, or five hundred. While the reduction of landfill waste of the disposable packaging is a laudable end in itself

Related links:
http://www.newyorker.com/reporting/2008/02/25/080225fa_fact_specter/
http://www.triplepundit.com/pages/ask-pablo-the-coffee-mug-debac-002246....