In May, New Jersey became the first state to ban single-use bags made from plastic or paper in large grocery stores. The new ban lumps both types of totes together, but one is actually worse for the environment than the other. Which one? Paper bags.
Surprised? Let's delve into the data underlying the case for plastic over paper.
A 2005 life-cycle analysis commissioned by the Scottish government found that manufacturing paper bags consumes 10 percent more energy than manufacturing conventional plastic bags, uses four times more water, emits more than three times the amount of greenhouse gases, generates 14 times more water pollution, and results in nearly three times more solid waste. A 2007 study commissioned by what is now the American Recyclable Plastic Bag Alliance, an industry group, found that, compared to making plastic bags, making paper bags takes 3.4 times as much energy, produces five times as much solid waste, emits twice as much greenhouse gases, and uses 17 times more water.
A 2011 study commissioned by the U.K.'s Environment Agency found that "the paper bag has to be used four or more times to reduce its global warming potential to below that of the conventional [plastic] bag." The report noted that "it is unlikely the paper bag can be regularly reused the required number of times due to its low durability." The report added that paper bags were "significantly worse" than plastic bags "for human toxicity and terrestrial ecotoxicity due to the effect of paper production."
Other factors include transportation and disposal. Two thousand single-use plastic bags weigh about 30 pounds, while 2,000 paper bags weigh 280 pounds. By one estimate, it takes seven trucks to transport the same number of paper bags as one truck loaded with plastic bags. Paper bags also take up more space in landfills.
A 2020 United Nations Environment Programme report looked at several life-cycle analyses published since 2010. "Paper bags contribute less to the impacts of littering," it concluded, "but in most cases have a larger impact on the climate, eutrophication and acidification."
With respect to environmental impact and consumer choice, New Jersey really should reconsider banning both plastic and paper.
This article originally appeared in print under the headline "Paper vs. Plastic".