Read the full story in The Conversation.
Governments are increasingly banning the use of plastic products, such as carryout bags, straws, utensils and microbeads. The goal is to reduce the amount of plastic going into landfills and waterways. And the logic is that banning something should make it less abundant.
However, this logic falls short if people actually reuse those items instead of buying new ones. For example, so-called “single-use” plastic carryout bags can have a multitude of unseen second lives – as trash bin liners, dog poop bags and storage receptacles.
A U.K. government study calculated that a shopper would need to reuse a cotton carryout bag 131 times to reduce its global warming potential – its expected total contribution to climate change – below that of plastic carryout bags used once to carry newly purchased goods. To have less impact on the climate than plastic carryout bags also reused as trash bags, consumers would need to use the cotton bag 327 times.
My research has evaluated carryout bag regulations from many angles. In a recent study, I examined how plastic carryout bag bans in California have changed the types of bags people use at checkout, as well as these bans’ unintended impacts on consumer purchasing habits. My results showed that bag bans may not reduce total plastic usage if people begin purchasing trash bags to replace the carryout bags they were previously reusing for their garbage. As this finding shows, well-intended product bans can have unintended consequences.