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OK, once and for all, which is more environmentally
friendly, paper or plastic, at the grocery checkout?
The city of San Francisco recently banned plastic
bags. Large supermarkets and pharmacies there must eliminate plastic
shopping bags by early 2008 in favor of bags made either from paper or
compostable and biodegradable cornstarch. The city’s Board of
Supervisors cited the fact that plastic bags are a challenge to recycle and
as a result occupy much-needed landfill space while causing litter problems
by easily blowing into trees and waterways, where they can kill birds and
marine life. But just because San Francisco has outlawed plastic
bags doesn’t mean that all indications point to paper bags’
being more green-friendly than plastic. A landmark 1990 study by the
research firm Franklin Associates — which factored in every step of
the manufacture, distribution, and disposal stages of a grocery bag’s
usable life — actually gave the nod to plastic bags.
Franklin employed two critical measures in reaching
its conclusion. The first was the total energy consumed by a grocery bag.
This included both the energy needed to manufacture it, called process
energy, and the energy embodied within the physical materials used, called
feedstock energy. The second measure used was the amount of pollutants and
waste produced. The Franklin report concluded that two plastic bags
consume 13 percent less total energy than one paper bag. Additionally, the
report found that two plastic bags produce a quarter of the solid waste, a
15th as much waterborne waste, and half the atmospheric waste of one paper
bag.
Of course, many environmentalists still side with
paper as a better choice than plastic at the checkout, mostly for the
reasons cited by San Francisco’s Board of Supervisors. Plastic is not
biodegradable, it litters our waterways and coastal areas, and it has been
shown to choke the life from unsuspecting wildlife. A recent survey by the
United Nations found that plastic in the world’s oceans is killing
more than a million seabirds and 100,000 marine mammals and sea turtles
each and every year. According to the California Coastal Commission,
plastic bags are one of the 12 most commonly found items in coastal
cleanups. Paper bags do not cause such after-the-fact problems and are
inherently easier to recycle. But to the nonprofit Institute for Lifecycle
Environmental Assessment, “Paper or plastic?” is not the
question we should be asking ourselves, because the answer is really
“Neither.” After all, energy and waste issues aside, the
manufacture of paper bags brings down some 14 million trees yearly to meet
U.S. demand alone, while at the same time plastic bags use up some 12
million barrels of oil each year. The group urges consumers to “just say no”
to both options and instead bring their own reusable canvas bags,
backpacks, crates or boxes to haul away the groceries. Some supermarkets,
such as the Albertson’s and Wild Oats chains, even offer a small
discount (around 5 cents) to those who do so. Another benefit of bringing
your own, of course, is setting a good example so that other shoppers might
do the same.
For more information:
Institute for Lifecycle Environmental Assessment, www.ilea.org.
Send questions to Earth Talk, care of E/The Environmental Magazine,
P.O. Box 5098, Westport, CT 06881 or e-mail earthtalk@emagazine.com.
This article appears in Sep 27 – Oct 3, 2007.
