Banning Plastic Bags Isn't Just Bad Economics—It's Bad For The Environment
Bill Wirtz, Foundation for Economic Education
In January, the British government announced its intention to extend their plastic bag tax to all shops. As of now, only establishments which have more than 250 employees need to impose the charge on single-use plastic bags. In the United States, certain states or cities even go beyond a tax and put an outright ban on them. But the UK government's own research suggests that this is actually bad for the environment.
Environmental Impact and Reuse
In 2011, the UK's Environment Agency published an earlier-drafted life cycle assessment of supermarket carrier bags. The aim: establishing both the environmental impact of different carrier bags which are in use and their reuse practice. The intention was to inform public policymakers about the impact that a crackdown on plastic bags could possibly have. Needless to say, politicians had little concern for the actual assessment the report presented.
In a section the report calls "global warming potential" (GWP), the agency assessed the environmental impact according to abiotic depletion (the disposal of products produced by crude oil), acidification (impact on soil, freshwater bodies, and the oceans), eutrophication (nutrients contained in water), human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity, and photochemical oxidation (air pollution). These impact categories were also aligned with the GWP assessment of the 2007 IPCC report on climate change.
The researchers then looked at the number of times that a bag would need to be reused in order to have the same environmental impact as the conventional HDPE (High-density polyethylene) bag that people are used to. They reach the following conclusion:
"In round numbers these are: paper bag - 4 times, LDPE bag - 5 times, non-woven PP bag - 14 times and the cotton bag - 173 times."
The attentive reader will now ask the correct deductive question: so what are the reuse levels that we experience in practice? Or: do people's behavior reflect the environmental impact of shopping bags accordingly?