[gruez]

>Other bags, such as sturdier plastic bags designed for reuse were much better options, needing only a few uses to break even, environmentally speaking.

"a few uses" is only true when you're only considering climate change. it's 50+ when you consider all factors.

>Anyway, 50+ (or 100+) uses - a year or two of weekly shopping - does not seem unreasonable for a cotton bag.

The issue here is that at 1 shopping trip per week, it's a little under 2 years to break even with disposable bags plastic bags (assuming you reuse the disposable bag once). To actually make a 50% reduction, you'd need to use it for 4 years. That's a lot of hassle (remembering to bring along the bags, storing it, etc.) for very little benefit (in absolute terms), considering how little materials are in each plastic bag. For instance, according to the table on page 55, each bag has greenhouse effect equivalent to 0.11kg of co2. Over 400 uses with 50% savings, that's 22kg of co2 saved. With the current market price for carbon offset credits (quick search puts it at $25/ton), that's $0.55 saved over 4 years. You might be able to scale that out to 10 bags, but that's still pretty low.

[chimprich]

No, that is not my understanding of the paper.

It's 4 uses for a heavy-duty "bag for life" to be better for the environment than a disposable one.

As supported by this Environment Agency report: https://assets.publishing.service.gov.uk/government/uploads/...

6 billion fewer plastic bags were issues in the UK after they started getting taxed. That's only a small amount of CO2 saved per bag, but not negligible on a national scale, and it's completely avoidable.

Plus you only have to have a very small percentage out of 6 billion bags escaping the standard refuse system for them to become an environmental problem in themselves.

I think it is well worth it.