Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

April 12, 2008

Relative Energy Cost of Food vs. Food Bags

Category: Conservation,Economics,Household,Organic & Local Food – Tom Harrison – 5:13 pm

Paper or Plastic? According to one article, the right answer seems to be “more vegetables.” The TerraPass blog did a very interesting article based on a study comparing the embedded energy of

  • Plastic Bags
  • Paper Bags
  • Vegetable Diet
  • Meat Diet

Their conclusion is simple: a meat diet is 186 times more energy intensive than the plastic bags used to carry it home. Paper bags were judged to be worse than plastic, meat worse than vegetables.

But, this is the wrong conclusion to draw from the facts.

I am of two minds when seeing articles like this.

On one hand, it is very important to have a methodology for estimating the “global warming impact” of any given good or service. The concept of “embedded energy”, or the total energy cost of a product during its life cycle is essential to developing a full understanding of the causes of problems, and their solutions.

However, the comparison is somewhat specious and wrongheaded. Their point is that food, especially meat, is a much larger contributor to climate change than packaging. True and very, very important; I have been writing about the energy cost of food for a while.

But is this a relevant point? It strikes me a little like asking the question “Who do you hate more, Bush or Cheney?”—it’s an unfair question because it is asking us to choose between two things by implicitly minimizing the importance of the other choice, and further the question implies both are bad. A fair question would be, “How would you compare Bush and Cheney?”.
(Not being a political blog, I’ll let someone else dig into that rat hole :-)

Another fair question would be “How does the energy cost of plastic compare to paper?” It’s also fair to compare meat vs. vegetable diets.

And while it is reasonable to stress the relative importance of one factor versus another, combining the comparisons may lead people to draw the wrong conclusions.

Here I write about the changes that we can make in our day-to-day lives that will result in a reduction of our contribution to various related problems: global warming, energy and a host of others (e.g. obesity, war, famine and disease).

Measuring only one factor is not wrong. Having a solid, agreed upon method of calculating embedded energy is important. It is not the only important thing, though.

The right conclusion to draw from the results of the study are:

  • Avoid eating meat, and realize how costly food is
  • Try to re-use bags at the store
  • Consider how the other things you take for granted affect the problem

The problem with conclusions like the one from the article:

Assuming that a grocery bag holds one day’s worth of food for a family of four, the choice about what to put in the bag is about 186 times as important as the bag itself.

is that they minimize the importance of considering the whole picture by diminishing the importance of things like reusing bags. Such conclusion also don’t address other related issues such as the energy efficiency of your vehicle, and whether you drive or walk to the store, and how far away you live from the store, etc. Driving your Chevy Suburban van 15 miles from your big house in the burbs might be important, too.

But none of these items are as “cute” as the clever comparison of bags vs. what you put in them.

We can get “too numerical” in addressing the problem here. Yes, climate change seems to be directly related to energy consumption. But what is the cause of our excessive energy consumption?.

My answer is that we have failed to fully understand the various impacts of every choice we make, as we live our comfortable American lives.

We have a major social issue here. Science, technology, accurate measurement, good economic models all will play a part in the solution. But none matter until we address the behavior changes we will have to make.


  1. Check out this US Carbon Footprint Map, an interactive United States Carbon Footprint Map, illustrating Greenest States to Cities. This site has all sorts of stats on individual State & City energy consumptions, demographics and much more down to your local US City level…

    Comment by ed — April 12, 2008 @ 11:49 pm

  2. Ed —

    Very cool map indeed. I’ll look more carefully and write up a post. Thanks!

    Comment by Tom Harrison — April 13, 2008 @ 12:55 pm

  3. Very interesting. I like your level-headed approach here. I’m glad I found this website.

    Comment by Tad — June 19, 2009 @ 1:40 am

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.