Paper or plastic?
Next time the cashier at the grocery store asks that question, choose
plastic if you want to save the environment, according to the Boston
Globe. And definitely skip the glass bottles of milk.
Why? Because paper bags and glass bottles cost more to make and more to transport, using up more oil than plastic, according to a piece called "In Praise of Plastic."
"A 2007 analysis - performed by an independent research firm
but paid for by the American Chemistry Council - looked closely at the
environmental impact of half-gallon milk jugs, and again plastic fared
well. The typical high-density polyethylene, or HDPE, jug was lighter
than other alternatives, required less energy to produce, and generated
in its life cycle (including shipping) less than half the greenhouse
gas emissions of glass and 25 percent less than paper milk cartons. The
study confirmed that plastic's major benefit is the fact that it's
lightweight. "There are a number of studies that have showed that
even though plastics are made from petroleum, they use less
petrol-chemical energy than glass," says Susan Felke, a professor of
packaging and the acting director of the School of Packaging at
Michigan State University. This fact, she adds, makes plastic the
better packaging choice in many cases, even if that's something the
general public doesn't appreciate. "It takes some understanding of the
complexity of the system," she says. "It's not intuitive." The
American Chemistry Council, representing the $268 billion plastics
industry, has used these sorts of arguments to make a case for the
industry in recent years, more and more in recent months. It's true,
says Kevin Swift, the council's chief economist, that about 169 million
barrels of oil were used to make plastic in the United States last
year. But that was less than 3 percent of our total oil consumption, he
says, "a rather modest amount." And perhaps the most controversial
subset of that total, plastic bags and other films, consumes a fraction
of the oil, Swift says - 5.3 million barrels a year. And just look,
industry officials point out, how much plastic can save elsewhere.
This durable, convenient product keeps food from
spoiling, allowing individuals to make fewer, more efficient trips to
the grocery store. Applying a thin layer of polyethylene wrap to just
one newly constructed house, they say, will save the equivalent of
roughly 8,300 gallons of gasoline over the next 30 years - enough to
fuel a mid-size sedan for 15 years or a hybrid for 27. Plastic parts in
cars save gasoline as well. Constructing just the bumper beam of a
Saturn VUE, for example, with plastic rather than metal saves 21/2
pounds and, therefore, according to the American Chemistry Council,
31/2 gallons of gas over the lifetime of one car. Not much, true. But
over the lifetime of an entire fleet of 200,000 cars, 700,000 gallons
of gas are saved. (The average vehicle today contains about 300 pounds
of plastic, so the savings can add up.) And industry officials are even
confronting the plastic bag's bad rap. They argue that plastic
bags require 70 percent less energy to manufacture than paper bags and,
because they're so much lighter, less energy to transport. It takes
seven trucks to deliver the same number of paper bags that would fit in
one truck if the bags were plastic, the American Chemistry Council
says. And if these arguments fail to persuade, plastics proponents can
always return to the fact that plastic bags and packaging are
recyclable. Instead of banning plastic, proponents argue, governments
should increase recycling efforts. In many cases, this would be a
relatively simple solution. "Plastic bags are made of polyethylene,"
says Bob Malloy, a professor and the chairman of the plastics
engineering department at UMass-Lowell. "In terms of the recycling of
material, there isn't anything in the recycling world more easily
recycled than polyethylene." And yet, for the most part, it isn't
happening, leaving a total of 27 million tons of plastic each year in
search of a landfill or incinerator near you.
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