Q: Is there a link between our plastic use and climate change?
Asked by Raul Nava, '05, Monterey, Calif.
Ah, plastics. We might be quick to smother this question with a long-winded attack on the plastics industry and plastics consumption entirely. After all, plastics are made from fossil fuels—four percent of the world's annual petroleum production is converted directly into making plastics, and another four percent gets burned to fuel the process. On top of whatever other problems we might have with plastic, surely this nonrenewable product must be a net contributor to our global climate problem, too. Yet the truth about plastics is a little more complicated.
Consider plastics in automotives, a lighter replacement for steel and other metal components. Or a plastic bottle compared to a much heavier glass one. Although plastics are more emissions heavy in the production phase in this comparison, their light weight enables greater transportation efficiency and a lower overall carbon footprint. In fact, if we listen to the chemical industry, the use of plastics more than offsets the greenhouse gas emissions of their production by a factor of 2 to 2.5. Bring on the plastic!
Or should we? There is a glaring omission in this rosy plastic picture. Even if we accept that plastics are more carbon efficient than alternative materials in transportation, we're still talking about vast amounts of carbon emissions. Indeed, plastics use releases at least 100 million tons, and maybe as much as 500 million tons, of carbon dioxide into the atmosphere each year. That's the equivalent of the annual emissions from 10 to 45 percent of U.S. drivers.
But here's the thing with plastics: that rather alarming carbon dioxide number could be much lower, if only Americans recycled more than the paltry 7 percent of plastic that presently gets a second shot at product life. What of the other 29 million tons of plastic that we threw out last year, 14 million tons of which were bottles and packaging? We burned it or tossed it in the landfill. We could cut energy use in plastics production by a third if we would just feed our insatiable appetite for the stuff with nonvirgin material. Globally, we could save the annual emissions equivalent of as many as 30 million U.S. drivers by closing the gap in the life cycle of plastic.
There are problems beyond our apparent collective inability to toss plastic water bottles into the recycling bin, of course. Many municipalities are unable to recycle many types of plastics, whether due to outdated equipment or because the technology is still emerging. And recycled bottles rarely re-enter the supermarket as new food containers. Traditional recycling techniques limit the use of soft, food-quality plastics to lower-grade end uses, such as playground equipment. That limitation may change as engineers find new ways to make recycling technology more efficient and cost competitive. Our production processes will doubtless become more efficient over time, our plastics ever lighter and our recycling more complete. But no new product will ever be carbon-neutral, and besides, the bottled water drinker's carbon conscience can be unburdened in much simpler ways. Reducing the number of bottles you buy and reusing the ones you do are still the remedies of choice for a culture too practiced in throwing things away. Grab a reusable water bottle, fill it with tap water and go. And use it again. And again. And again. . . .
Samantha Staley plans to receive her master's degree in earth systems in 2009.