Which grocery bag leaves the smallest carbon footprint on the planet?
How does one know which kind of grocery bag is the most environmentally friendly? The answer lies in three areas: how it is made, how it is used, and how it is disposed of.
Production: Plastic bags win in this category. Paper grocery bags require a lot of water, fuel and, of course, trees. The fertilizers and chemicals used in tree farming and bag manufacturing contribute to acid rain. Paper grocery bags are rarely made from recycled material as they need longer, stronger fibers. Cloth bags are usually made from cotton, a pesticide intensive, water guzzling crop. Of course plastic is derived from petroleum which is a finite material as compared to trees and cotton.
Use: Once we bring home a plastic bag, it has a number of uses: taking out the trash, picking up dog poop, getting rid of the kitty litter. When plastic grocery bags are banned, the sales of small plastic trash bags skyrockets to fulfill these purposes. Thirty percent of the plastic eliminated by the ban comes back in these thicker plastic bags. A paper bag must be used 3 times to negate their higher climate-warming potential. Because they tear easily and don’t hold up well when wet, their reuse is limited. A cloth bag must be reused 131 times before it is better for climate change than a plastic one. The nonwoven PP bags only have to be reused 11 times to equal the carbon footprint of plastic bags.
Disposal: Paper bags win here as they can be composted if torn into small pieces and are recyclable. Plastic bags are not very recyclable and wind up clogging drains, littering parks, beaches and the ocean and killing wild life.
So what kind of grocery bag is best?: Experts agree that the more you use a bag, the better it is for the environment. The best reusable bags with the lowest carbon footprint seem to be the ones made from nonwoven polypropylene. So use the bags you will reuse most often, dispose of them in a climate friendly way and don’t buy plastic bags to replace the ones from the grocery store you would use for trash, dog poop and kitty litter.