Over 200 municipalities in the United States, including two in New Mexico – Santa Fe and Silver City – have banned the distribution of lightweight plastic shopping bags. Proponents of these bag bans claim they will reduce litter and protect the marine environment, diminish our consumption of resources and emissions of greenhouse gases, reduce waste and save taxpayers’ money.
Unfortunately, for those who see banning plastic grocery bags as a panacea, a recent report for the Reason Foundation shows that all these claims are false.
Authoritative studies show that plastic bags constitute less than 1 percent of visible litter in U.S. cities. The presence of plastic bags in trees and on the ground signifies that a community has a litter problem. The appropriate response is to reduce and ameliorate that problem through education and other initiatives – not to ban plastic bags.
Members of some pressure groups claim that plastic bags kill large numbers of marine animals. Even for bags distributed in coastal cities, that claim is simply false.
As David Santillo, a senior biologist with Greenpeace, told The Times of London: “It’s very unlikely that many animals are killed by plastic bags. The evidence shows just the opposite … . On a global basis, plastic bags aren’t an issue.”
Because they are so strong and light, plastic shopping bags can actually reduce the amount of waste that ends up in landfills.
About 80 percent of all grocery bags in the U.S. are made from lightweight plastic but constitute only 0.4 percent by weight of all waste sent to landfills.
Paper bags, which account for most of the remaining 20 percent of grocery bags used, generate the same amount of waste (0.4 percent of the total) because each bag is far heavier.
New Mexico’s plastic bag bans have likely increased the amount of waste produced as people switch to paper, which would actually increase the costs of municipal solid waste disposal.
Some alternative bags appear to be superior to lightweight plastic on some environmental measures, such as use of energy and emissions of greenhouse gases. But that is true only if those bags are reused a sufficient number of times (ranging from six to 30 or more, depending on the type of bag). In practice, households do not typically reuse their bags enough to achieve those gains.
At actual reuse rates, lightweight plastic bags result in about half the energy consumption and greenhouse gas emissions of alternative bags, whether those alternatives are paper or reusable.
Likewise, at actual reuse rates, all alternative bags are associated with greater water use.
Reusable bags are the worst, resulting in the use of at least 10 times as much water as lightweight plastic bags – if households wash their bags regularly. And such washing is strongly advised: Studies show that about half of unwashed bags contain potentially dangerous germs; meanwhile, failure to clean reusable bags regularly has resulted in several instances of serious illness.
So, banning lightweight plastic bags likely increases energy use, water use and emissions of greenhouse gases, but does not substantially reduce waste or litter, or the cost of associated municipal waste and litter collection.
If communities are concerned about litter, the best solution is likely a campaign directly addressing that problem.
Advocates of banning plastic grocery bags, while perhaps well-intentioned, are actually harming the environment, raising consumer costs and reducing personal freedom.
That sounds like a bad deal to me.