I’ll admit it:  I’m a bit of a skeptic about the anti-plastic bag hullabaloo. Just about every study I’ve seen suggests that, when you compare plastic bags with paper grocery sacks, plastic is the unexpected winner:  they produce less air and water pollution, take up less space in landfills, consume less energy over their life cycles, take less energy to recycle, and are responsible for lower levels of global warming emissions.  


And I’m not just talking about industry-funded studies either:  as far as I can tell, disinterested academics find the same things.  This old Washington Post infographic isn’t definitive, but does a decent job of summarizing the statistics.

But perhaps more importantly, all the attention that gets focused on the paper-vs.-plastic debate is something of a distraction.  When we looked at the issue a few years back, we discovered that the environmental impact of decisions in the grocery aisles were way, way more important than bag choices. The chart to the right shows the “embodied energy” in a high-carbon sack of groceries, a lower-carbon alternative diet, and in the bags themselves.  Clearly, if you don’t think about the impacts of your personal choices until you’re in the checkout line, you’ve waited too long. 

So given all that, why do I think that the proposed Oregon law to ban plastic bags deserves lawmakers’ support?

Three reasons:

First, it’s not just about plastic bags.  The legislation would also establish a nickel fee on paper bags as well.  Experience from  Ireland and Washington, DC, among other places, shows that bag fees can be very effective at encouraging shoppers to use reusable bags.  And the studies I’ve seen find reusables superior to both paper and plastic.  So Oregon’s proposed law wouldn’t simply encourage a switch from plastic to paper—an iffy trade-off at best—but instead would reduce the demand for disposable bags of all sorts. 

Second, plastic bags have other external costs that most life cycle studies don’t pick up. Plastic bags do escape the waste stream—where they’re unsightly, and may create risks for marine life. (That said, as far as I can tell bags themselves are a relatively small part of a much bigger problem with plastic debris in the oceans—with plastic fishing gear being a far, far bigger direct risk to most wildlife, and the impacts from plastic breakdown products still a big unknown.) 

Closer to home, plastic bags have been a real problem for recyclers.  The bags clog up recycling machinery so badly that one Oregon-based recycler recently estimated that 20 to 30 percent of their total labor costs were related to plastic bags—pulling them from the rest of the recycling stream, untangling them from their equipment, and stopping all work when bags clog up the machines—and about 7 percent of otherwise recyclable paper has to be landfilled because of plastic contamination.  So plastic bags in the recycling stream likely undermine the effectiveness of recycling efforts overall.

And then there’s the fact that plastic bags are a major contributor to clogged sewers—which costs cities like Portland big money, according to Portland mayor Sam Adams.


A third reason to support Oregon’s proposed bag ban is, well, just on general principles. We need to stop pretending that “free” things have no external costs!!  Even if the precise costs are difficult to pin down, they’re certainly not zero. And as a community, we’re perfectly within our rights to start doing something to control them.  And the right kinds of community standards—including both bans and fees—have proven far more effective than lecturing and moral suasion. 

Still, I do have to marvel that plastic bags generate so much public animus. There are so many other things that deserve our attention more. Coal power, for example, causes many orders of magnitude more harm than plastic bags.  That doesn’t mean that efforts to promote reusable bags aren’t worthwhile—they are!! But still, the attention we give to bags may show something important about human nature:  all too often, our attention and concern is drawn more to what’s visible in our daily lives than to what’s truly important.