It was only about 40 years ago that plastic bags became standard at U.S. grocery stores. This also made them standard in sewers, landfills, rivers and the Great Pacific Garbage Patch. They clog drains and cause floods, litter landscapes and kill wildlife. The national movement to get rid of them is gaining steam, with more than 240 cities and counties passing laws that ban or tax them since 2007. But these bans may be hurting the environment more than helping it.
According to research by economist Rebecca Taylor, the introduction of plastic bag bans in California in 2016 reduced the state's plastic waste by 40 million pounds per year. But people who used to reuse their shopping bags for other purposes, like picking up dog poop or lining trash bins, still needed bags. "What I found was that sales of garbage bags actually skyrocketed after plastic grocery bags were banned," she says.
Trash bags are thick and use more plastic than typical shopping bags. "So about 30 percent of the plastic that was eliminated by the ban comes back in the form of thicker garbage bags," Taylor says. On top of that, cities that banned plastic bags saw a surge in the use of paper bags, which she estimates resulted in about 80 million pounds of extra paper trash per year.
A bunch of studies find that paper bags are actually worse for the environment. They require cutting down and processing trees, which involves lots of water, toxic chemicals, fuel and heavy machinery. Together with the uptick in plastic trash bags and huge increase of paper, banning plastic shopping bags actually increases greenhouse gas emissions. That said, at least these bans reduce non-biodegradable litter.
