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Dartmouth College Office of Public Affairs Press Release
Better individual decisions can have a greater environmental impact
Three Dartmouth researchers have found that resisting the temptation to buy an SUV can benefit the environment much more than recycling. They say that while recycling of some materials does contribute to overall environmental improvement, other personal decisions, such as what kind of car you drive, have a much greater environmental impact.
Andrew J. Friedland, professor and chair of environmental studies, and his colleagues Tillman U. Gerngross, associate professor at Dartmouth's Thayer School of Engineering, and Richard B. Howarth, associate professor of environmental studies, conducted the research which appears in the April issue of the Elsevier journal, Environmental Science & Policy. They examined two individual activities, recycling and use of automobiles, and compared their relative environmental benefits.
The authors found that during the past 20 years or so, the amount of material recycled has steadily gone up, and during that same time, fuel efficiency has gone down, because Americans are choosing less fuel efficient vehicles. The authors argue that if the mix of cars and SUVs (which in this study includes sport utility vehicles, light trucks and minivans) had stayed at the 1989 level, it would have saved 75 times more energy a year than what has been saved by recycling plastic, and four times more energy than what has been saved by recycling aluminum.
"Individuals in our society have good intentions," says Friedland, the lead author. "They want to do something good for the environment. I was struck by the perception that many people think that recycling is the most important thing that they could do. In fact, making better transportation decisions would have more environmental benefit."
In this study, the researchers focused on energy use, which is a good indicator of environmental impact, because it affects a variety of environmental factors such as air and water pollution, global warming, and in some cases, local species.
The researchers considered recycling plastic and aluminum and used life-cycle analysis (LCA), which measures the energy and materials required to create an item and again to recycle it. For example, the study states that making a can from recycled material requires 94 percent less energy than making one from new aluminum. Assessing the benefits of plastic recycling is more difficult. Once it arrives at a recycling center, plastic is washed and chopped up, and the energy expended in this process is almost half of the energy required to produce brand new plastic, according to the study. The additional energy used by the consumer to clean the plastic before it's recycled is difficult to measure and quantify.
For comparison purposes, the researchers looked at the number of SUVs, light trucks and minivans registered from 1989 to 1999, which increased from 31 to 44 percent of all cars registered. They used data from the US Bureau of Transportation statistics for information on miles driven and fuel consumed to measure energy use.
"People see recycling as pure good," says Howarth, "but it's more complicated than that."
Friedland agrees. "It's a lot harder to get people to drive less or drive a more fuel-efficient car. Those are harder things to market and to convey to people."
The authors also argue that government policy appears to favor recycling over choosing fuel-efficient vehicles, public transportation and less travel.
"Our study illustrates how poorly consumers understand the environmental impact of their actions and how public policy is driven by a very superficial understanding of the relevant issues as well," says Gerngross.
- Susan Knapp
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