A few years ago, for my newspaper day job, I interviewed someone who was working to “green” a big outdoor festival here in Pittsburgh. One strategy was to require all the food vendors – chicken on a stick, etc. – to use plastic cups and utensils made from plant materials. Such materials are readily compostable, and are not made directly from petrochemicals, which are widely noted for their toxicity.
Still, such items are stuff that gets produced, used once and tossed (even if it’s into a compost pile). But my interview subject mocked the suggestion that the problem was our throwaway culture. “Should everyone have just one fork their whole life?” he asked rhetorically.
About a month ago, researchers at the University of Pittsburgh put an interesting spin on the notion of “green plastics.” They found that while the finished products are more environmentally friendly, plant-based plastics – “biopolymers” — are actually dirtier to manufacture than are oil-based synthetics. The reason is basically that industrial agriculture is rather toxic business too.
An Oct. 21 Pitt press release summarizing the findings read in part:
“Biopolymers trumped the other plastics for biodegradability, low toxicity, and use of renewable resources. Nonetheless, the farming and chemical processing needed to produce them can devour energy and dump fertilizers and pesticides into the environment …
“The researchers examined 12 plastics—seven petroleum-based polymers, four biopolymers, and one hybrid. The team first performed a life-cycle assessment (LCA) on each polymer’s preproduction stage to gauge the environmental and health effects of the energy, raw materials, and chemicals used to create one ounce of plastic pellets. They then checked each plastic in its finished form against principles of green design, including biodegradability, energy efficiency, wastefulness, and toxicity. …
“Biopolymers were among the more prolific polluters on the path to production, the LCA revealed. The team attributed this to agricultural fertilizers and pesticides, extensive land use for farming, and the intense chemical processing needed to convert plants into plastic.”
The report, written by lead author Michaelangelo Tabone, was published in the journal Environmental Science & Technology. You can find some graphs and charts here: http://www.news.pitt.edu/news/Landis_polymers_LCA.
Advocates of plant-based plastics can point to the fact that despite the toxicity of their manufacture, these materials can still turn out to be the greenest overall: A sugar-based plastic from NatureWorks was found to be the most environmentally friendly.
But the contest isn’t nearly as close as you’d hope. After all, the ill effects of making biopolymers are rather horrible.
For example, says the press release: “All four biopolymers were the largest contributors to ozone depletion.”
Moreover: “The two tested forms of sugar-derived polymer—standard polylactic acid (PLA-G) and the type manufactured by Minnesota-based NatureWorks (PLA-NW), the most common sugar-based plastic in the United States — exhibited the maximum contribution to eutrophication, which occurs when overfertilized bodies of water can no longer support life. One type of the corn-based polyhydroyalkanoate, PHA-G, topped the acidification category. In addition, biopolymers exceeded most of the petroleum-based polymers for ecotoxicity and carcinogen emissions.”
Given the share of blame that large-scale, industrial agriculture holds here, think for a second what all this says about the damage we do just by growing our food with synthetic fertilizers.
But mostly, think about the choices we’re usually presented for helping the environment.
Worried that your car is adding to global-warming? Get one with better mileage – you’ll add to global warming 50 percent slower.
Think coal-fired power plants are dirty? Burn natural gas! (Well, not really: Though it’s got half the carbon emissions of coal — which is sort of like winning the tallest-gnome contest — the methane emissions that accompany gas drilling might wipe out even that advantage.)
And you can keep buying whatever you want, as long as you recycle whatever’s left when you’re done. (Even though recyclables are usually merely packaging, and the stuff that came in the package was probably worse for the environment than the wrapper.)
These are some of the choices that corporate green-talkers ply us with. It’s real have-your-cake-and-eat-it-too stuff, a way to make sure people don’t feel guilty about buying more products nobody actually needs – things like disposable forks.
Sadly, it’s all but little different than what sickly green, techno-positive consumer-economy-friendly enviros would have you believe.
The problem is that everything we manufacture costs the earth something; almost none of it is strictly sustainable. And the benefits of doing things “differently,” if they exist at all, are often so vanishingly small they’ll never add up to enough to prevent the dire ecological emergencies we’ve created.
We’re not going to invent our way out of a crisis we invented by inventing. The only way to do it is with the stuff we don’t buy – one unbought plant-plastic fork at a time.