(p. A25) Back in 2011, Britain’s Environment Agency conducted a life-cycle assessment of various bag options, looking at every step of the production process.
. . .
That same British analysis also looked into reusable options, like heavier, more durable plastic bags or cotton bags. And it found that these are only sustainable options if you use them very frequently.
Making a cotton shopping bag is hardly cost-free. Growing cotton requires a fair bit of energy, land, fertilizer and pesticides, which can have all sorts of environmental effects — from greenhouse gas emissions to nitrogen pollution in waterways.
The study found that an avid shopper would have to reuse his or her cotton bag 131 times before it had a smaller global warming impact than a lightweight plastic bag used only once. And, depending on the make, more durable plastic bags would have to be used at least 4 to 11 times before they made up for their heftier upfront climate costs.
So if you’re going to opt for a reusable bag for environmental reasons, make sure you actually reuse it — often.
For the full story, see:
(Note: ellipsis added.)
(Note: the online version of the story has the date March 29, 2019, and has the title “Plastic Bags, or Paper? Here’s What to Consider When You Hit the Grocery Store.”)