What should we do with plastic bags — recycle, reuse, throw out, or ban them?

John Tierney writes in the Wall Street Journal:

researchers have found that laws restricting plastic bags and food containers don’t reduce litter. The resources wasted on these anti-plastic campaigns would be better spent on more programs to discourage all kinds of littering.

Another myth—that recycling plastic prevents it from polluting the oceans—stems from the enduring delusion that plastic waste can be profitably turned into other products. But sorting plastic is so labor-intensive, and the resulting materials of so little value, that most municipalities pay extra to get rid of their plastic waste, mostly by shipping it to Asian countries with low labor costs. The chief destination for many years was China, which two years ago banned most imports. It now goes to countries like Malaysia, Indonesia, Thailand and Vietnam. Some of the plastic from your recycling bin probably ends up in the ocean because it goes to a country with a high rate of “mismanaged waste.”

Yet single-use plastic bags aren’t the worst environmental choice at the supermarket—they’re the best. High-density polyethylene bags are a marvel of economic, engineering and environmental efficiency. They’re cheap, convenient, waterproof, strong enough to hold groceries but thin and light enough to make and transport using scant energy, water or other resources. Though they’re called single-use, most people reuse them, typically as trash-can liners. When governments ban them, consumers buy thicker substitutes with a bigger carbon footprint.

Once discarded, they take up little room in landfills. That they aren’t biodegradable is a plus, because they don’t release greenhouse gases like decomposing paper and cotton bags. The plastic bags’ tiny quantity of carbon, extracted from natural gas, goes back underground, where it can be safely sequestered from the atmosphere and ocean in a modern landfill with a sturdy lining.

If the goal is to reduce carbon emissions and plastic pollution, we can take some obvious steps: Repeal misguided plastic-bag bans. Stop exporting plastic waste to countries that allow it to leak into the ocean. Help those countries establish modern systems for collecting and processing their own plastic waste. Send plastic waste straight to landfills and incinerators. Step up enforcement of laws and treaties that restrict nations from polluting the ocean and prohibit mariners from littering the seas.