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.