Hotseat: David Tyler

A chemist walks into a bar and tells the hipsters drinking there that their locally brewed organic ale is bad for the environment.

There's no punch line: Beer is just one of the many beloved things that David Tyler, the Charles J. and M. Monteith Jacobs Professor of Chemistry at the University of Oregon, says aren't as eco-friendly as we think. 

And he's fond of challenging conventional ideas about the environment—and for noting that even with all the green cred Portland gets, there's a lot more that environmentally conscious hipsters could do to shrink their carbon footprint.

Tyler, age 60, headlines the next OMSI Science Pub. He spoke to WW about our consumption of oil, his research into degradable plastic bags, and the remarkable environmental damage inflicted by my favorite pair of jeans.

WW: You were quoted recently saying there are good environmental things about plastic bags. How can that be true?

David Tyler: They have the lowest carbon footprint, the lowest water use, and the lowest municipal waste [of any bagging option]. A plastic bag in many impact categories is better than a tote bag, it's better than a paper bag.

There are environmental trade-offs when you pick this product over another one. When you use plastic bags rather than paper bags or cotton bags, there's much less waste going into landfills. Where plastics fall down is that they don't degrade, so they get into lakes and streams and harm wildlife. 

Portland in 2011 banned plastic bags in stores. Did we make a huge mistake?

It comes back to what environmental impact you're trying to alleviate. If you're worried about global warming or the amount of waste going into landfills or the amount of water used to make a bag, then yes. But if they're worried about plastics in the environment and their effects on wildlife and litter, then no, they didn't. 

But what about nonrenewable resources, like petroleum, that go into making plastic? 

The manufacture and use of plastic actually contributes very little, relatively speaking, to our carbon footprint. Only between 3 and 6 percent of [petroleum] is used to make plastics, medicines and things like that. Why go after this small-time player? What we should be doing is driving less.   

You're researching plastics that would degrade in light. Will we ever switch over to that kind of bag?

When you make plastics that are degradable, it costs a little more. So are people willing to pay that extra cost? The plastic we have now would never go commercial because it would be double the price of the plastic. 

But ideally our finished product would be only a couple percent more expensive, something that people could easily afford. But once again, that's the ideal. 

Wouldn't the plastics industry fight it?

Probably just the opposite. I don't think it threatens their business model in any way. It probably enhances it—like, "Oh look, we can make this product more environmentally friendly and sustainable."

Wouldn't that mean using less petroleum? 

Well, no. You'd still have to make the plastic bag, and then it just degrades because it wasn't recycled. You might argue they'd make more bags. 

I try very hard to present the facts. I resent it when people say I'm a shill for the plastics industry, or the paper bag industry. I'm not. The way to approach these problems is to look at the data and the life-cycle assessments. I have a little fun with it, because some of the stuff is counterintuitive.

And those cotton tote bags?

Twenty-five percent of all pesticides are used on cotton in this country. Cotton is also an extremely thirsty crop. There are some horrible stories from the Environmental Justice Foundation about Uzbekistan, where they dried up whole rivers to irrigate their cotton. One pair of jeans—we'll say specifically Levis 501—requires over 900 gallons of water in its life cycle. 

What are some things Portlanders cherish that we don't think about as being harmful to the environment?

Everyone is usually sitting around these science pubs drinking beer. The carbon footprint for a pint of beer is 4 pounds. It just blows my mind that every time I sit down for a pint of beer, 4 pounds of carbon dioxide is released into the atmosphere. 

Is there a certain not-so-sustainable product you couldn't give up?

Beer is a great example. That would be really tough.

GO: Tyler will speak at the OMSI Science Pub on Monday, Aug. 5, at 7 pm at McMenamins Bagdad Theater and Pub, 3702 SE Hawthorne Blvd., omsi.edu/sciencepubportland. $5 suggested donation. Under 21 permitted with legal guardian.

WWeek 2015