The Importance of Plastic Bags

Posted by Eric de Place

04/02/2008 12:05 PM

Comparing paper, plastic, and what's inside.

paper versus plastic

In light of Seattle's proposal to charge a 20-cent per bag fee on paper and plastic grocery sacks, I thought I'd reprise one of my favorite posts from 2007.

Read the full thing here: Paper versus Plastic -- the Final Analysis, written by then-intern Justin Brant. The upshot is that Justin crunched the numbers and found out what's really going on with our groceries. (And no, the big finding is not that paper is worse. Argh.)

This chart gets to the heart of the matter, by comparing the energy embodied in hypothetical bags of groceries.

I'm not trying to nitpick the policy. I think Seattle's proposed fee is a fine idea (and it's something that European countries have been doing for years and years). It's just worth remembering that by the time you get to the check-out line, you've already made the more important choices.

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Comments

Posted by Milan 04/02/2008 03:12 PM

Unfortunately, raising meat taxes is politically impossible.

Posted by Richard 04/03/2008 04:55 PM

This is a very nice figure because it gets us away from the paper vs. plastic wars. Sometimes we get bogged down in what is really a very minor problem? this figure puts the focus back on individual choice.

What we put in the bags is by far more important for our overall energy uses. But it is much more complex than paper or plastic. How much energy is used for free-range chicken vs cage-raised? Is it a worthwhile endeavor to make the consumer choice to buy organic meat in order to first drive the market forces there, as a transition to a more veggie-based diet?

What is the energy difference between organic veggies and regular veggies? Should we encourage farm crops from other countries by buying food out of season for the Northern Hemisphere (i.e. bananas from the Southern)? That is, encourage third world economies even though there may be increased energy usage.

And then, finally, I have to trust that whoever calculates these numbers does so without an agenda? It would be nice to have some direct market forces that include all of this in the price instead of ignoring much of it. That would make things easier and a little less complex. Maybe.

Until then, I solve the paper vs. plastic conundrum by other measures - quantity (try to use whichever one will be maximally filled with the least number of bags), other uses (plastic can be used to carry many things while paper is good for storing a lot that needs to 'stack' well), and recycle (plastic cannot be put into our recycle bins so I can carry out a lot of recycle in a single paper bag and dump the lot in the recycle bin).

It may not be the most effective system for correct energy usage but it does require me to be a more active participant in that decision.

Few of us will be 'pure' regarding this. The goal should be to inform, to allow better decisions as we move towards a greener world. To create wisdom by increasing our knowledge.

Posted by MVP 04/04/2008 02:05 AM

Here in Eugene, many grocery stores give you a 5-cent REFUND when you bring your own bag. (It may even be 5-cents per bag.)

But, I suspect that CHARGING 20-cents per bag could be a much stronger motivating force than giving a refund, in this case!

Posted by Heather Trim 04/04/2008 03:28 PM

Hi all,

I appreciate that there are other calculations that can be done - within the framework of our consumer-oriented society - which will highlight other environmental problems, but let's not diminish the problem of plastics in marine waters and the resulting input of plastics (endocrin disrupters and more) into our food web. There are many facets to this issue.

Best,
Heather

Posted by Gary Walter 04/04/2008 03:43 PM

Having flirted with a vegetarian diet off and on for the past 30 years - and now reaching a level of about 90% vegetarianism (mainly because of my wife's good cooking), I've always heard that a meat-based diet consumes about 10x the grain as a vegetarian diet. Or, put another way, for every pound of protein that cow provides, it has to consume 10 pounds of protein in the form of who knows how many pounds of grain.

This graph is very enlightening. Thank you! It certainly puts things into focus. How often are we penny-wise and pound foolish?

Posted by Matt Leber 04/04/2008 05:17 PM

Is Seattle trying to reduce plastic bag consumption to cut down on energy use, or are they more interested in plastic's effect on the environment when it gets loose? (i.e. The plastic floating in the sea that kills unsuspecting wildlife looking for a snack?) Personally, I'm not terribly concerned about the energy usage of plastic bags. I used to choose them over paper for that very reason.

If you could make a graph that shows environmental impacts of plastic vs other materials based on weight, or even energy usage, I'd bet plastic would be the hands down winner (actually, looser). Think about it - something very light, that takes very little energy to produce, but impacts multiple levels of the food chain for dozens, or even hundreds of years. Graph that Eric! ;)

Posted by Mike OBrien 04/04/2008 05:40 PM

How is the embodied energy calculated? Is that the amount of petroleum energy or total energy? Vegetables obviously contain a lot of solar energy, but I'd think that should be excluded in the measure of vegetables (and beef too).

Posted by Morgan 04/05/2008 01:33 AM

Heather's and Matt's comments remind me of how when we're deep in thought about climate change, we often forget a whole world of other extremely important issues that used to be enough to motivate us.

Posted by Vickie 04/09/2008 08:20 AM

I have a question for those of you who have already made diet changes to eat locally produced food. I am struggling here. What should a person eat if they live in the north where the growing season is shorter and there is nothing (but meat) produced all winter?
Everything seems to be trucked in from somewhere.