You've probably been told that the right answer is paper – unless you want to hasten climate change and choke marine life. But the plastic bag has been wrongfully convicted. And labeling it as an environmental villain – and banning its usage – is blinding us to better behavior.
Plastic bags haven't always been Public Enemy No. 1. Introduced by Safeway and Kroger in 1982, they soon dominated the grocery bag market – by 1996, 80 percent of all bags were made from lightweight plastics. Customers loved 'em. They became thinner, lighter and able to contain more recycled material. And then…the tide turned.
In 2007, San Francisco became the first major city in America to ban the lightweight plastic shopping bag. Since then, over 150 municipalities across the country, including the cities of Seattle, Los Angeles, and Chicago have passed ordinances imposing similar bans. Most of these ordinances also include mandatory fees on paper and "reusable" plastic bags – like the five cent bag tax in Washington, D.C. In California, home to around 100 plastic bag bans, the state senate is considering a bill (SB 270) that would impose restrictions statewide.
Related: Will New EPA Rules Change Our Carbon Future?
Where did this ire come from? Ban proponents claim that restricting the distribution of plastic bags will have significant environmental benefits and reduce municipal costs. That means money saved for taxpayers. In a recent study for Reason Foundation, Brian Seasholes and I investigated these claims and found they're mostly untrue.
Let's start with the basic environmental claims: Banning plastic bags won't make litter disappear, dissipate litter removal costs, or kill innocent animals. Plastic bags constitute a tiny proportion of all litter, so banning them has very little impact on the amount of litter generated. A recent review of numerous analyses of litter in our streets found that plastic shopping bags constituted one percent or less of visible litter in the United States. They also comprise only .4 percent of all municipal solid waste that's discarded. To that end, there's no evidence that banning plastic bags has reduced litter removal costs, and it won't do much in the way of reducing trash collection costs, either. This first point isn't surprising since litter removal tends to be done by municipal employees or contractors who are not paid per item, so a tiny reduction in the number of items of litter generated makes essentially no difference to costs of removal.
At sea, the impact may be even smaller. Plastic bags have not caused a giant "garbage patch" in the North Pacific. Sure, plastic in the oceans has increased over the past four decades, corresponding to the increase in plastic use in general. Yet the notion that this has resulted in a gigantic landfill at sea is contradicted by the evidence, which shows that most plastic in the oceans is widely dispersed and in the form of tiny pieces.
Plastic bags aren't threatening the fish, either. Or birds for that matter. Claims that plastic bags kill hundreds of thousands of marine animals seem connected to a misreading of a study that investigated the impact of discarded fishing gear. As David Santillo, a senior biologist with Greenpeace, explained to The Times of London: "It's very unlikely that many animals are killed by plastic bags. The evidence shows just the opposite…. With larger mammals it's fishing gear that's the big problem. On a global basis plastic bags aren't an issue."
So the animals are safe– but what about us and our homes? Another common claim is that plastic shopping bags block storm drains, so banning them will reduce the risk of flooding. That's not true. Reducing litter in general and cleaning storm drains are far more effective solutions to the problem.
Okay, you say, but what about the use of resources and emissions of greenhouse gases? Those must be pretty bad, right? Wrong again. Lightweight plastic shopping bags are made from high density polyethylene, the feedstock for which – ethylene – is nearly entirely (over 97 percent) derived from natural gas. Given the newfound abundance of such gas in the United States and globally, there is little reason to be concerned about plastic shopping bags as a significant cause of resource depletion. And if you look at the per bag consumption of energy, water and emissions of greenhouse gases across different types of bags, those numbers are far lower for lightweight plastic bags than for paper or reusable ones.
Of course that does not tell the full story, since some bags are reused more than others. Surveys suggest that most people reuse their lightweight plastic bags, mainly for trash disposal, and on average each one is used 1.6 times. By contrast, paper bags are typically used only once. The thicker plastic bags, made from low density polyethylene, now being promoted as "reusable," typically are used about 3.1 times.
All of this means that an average consumer using only lightweight plastic bags consumes less energy and water and generates fewer greenhouse gas emissions than a consumer sporting a Whole Foods tote. Perversely, restrictions on the distribution of plastic bag likely results in an increase in the overall environmental impact of the bags we use to shop.
Not to mention that reusable bags are kind of disgusting, from the public health perspective. Putting food into bags that have previously been used to carry perishable items poses a health risk. Several outbreaks of food-borne diseases have been traced to unhygienic reuse of bags. To solve this problem, consumers are advised to disinfect bags before reuse – a process that consumes resources and time – and to store bags away from sources of germs. Surveys suggest that consumers rarely wash or otherwise disinfect their reusable bags. What a surprise.
If that's not enough to sell you, consider this: plastic bag bans and mandatory fees on alternative bags disproportionately affect the working poor, for whom the cost of paying for bags represents a greater burden. A dollar spent on ten paper bags is a dollar not available for other purchases. That obviously matters more to a household on a tight budget.
Let's bag the ban. I'll take plastic, please.