[gruez]

>when you really go shopping you should and can easily bring a bag when you go shopping.

There's a Danish study[1] that concluded that reusable bags require 50+ uses before breaking even with disposable plastic bags. And that's for one use. If you reuse the disposable bag once (to line your garbage bin, for example), the break even point is now 100+ uses. If you factor in cleaning costs for the reusable bags, I'd be surprised if this practice makes a dent on pollution, if at all.

[1] https://www2.mst.dk/udgiv/publications/2018/02/978-87-93614-...

[fogetti]

I don't exactly understand what you are saying but the report you linked shows that the non-reusable plastic bags reach the same negative impact on climate change 150 times faster than reusable cotton bags. How is that good?

When you talk about breaking even you are talking about reaching the same negative impact, I hope, because that's what the report is about.

They even spell out those negative impacts: ozone depletion, terrestrial eutrophication, freshwater eutrophication and water use.

[chimprich]

That is a very selective interpretation of that paper.

The study found that some types of reusable bag needed many uses before being a better environmental option than thin plastic bags (e.g. cotton). Other bags, such as sturdier plastic bags designed for reuse were much better options, needing only a few uses to break even, environmentally speaking.

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

[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.

[KozmoNau7]

That study only looked at resource usage, and not the consequences of carelessly discarded shopping bags clogging up rivers and beaches.

The best shopping bag to use is still an upcycled bag made from otherwise discarded material, as you are not creating demand for the production of new bags. Sail cloth is a good sturdy fabric, and a bag made from it will literally last you a lifetime.

[gruez]

>and not the consequences of carelessly discarded shopping bags clogging up rivers and beaches.

1. plastic garbage winding up in rivers is largely a developing country problem. I don't see many plastic bags (if at all) in my local waterways.

2. why not just responsibly dispose of those bags? It's not hard. They're not going to get lost when you're using them. After that, you're probably home, or at least some place with a garbage bin.

>The best shopping bag to use is still an upcycled bag made from otherwise discarded material, as you are not creating demand for the production of new bags. Sail cloth is a good sturdy fabric, and a bag made from it will literally last you a lifetime.

Are you suggesting people to make DIY cotton bags from scrap fabric they find themselves? You might be able to avoid the high costs of cotton (break even of 7000+ uses), but if you're not into arts and crafts, I suspect the opportunity cost will eat up any savings (if any).

[KozmoNau7]

>"why not just responsibly dispose of those bags? It's not hard."

And yet a lot of people carelessly throw away their plastic bags. Their laziness trumps your "it's not hard". Something primarily being a problem in developing countries is not an excuse for not caring about it.

"I don't see any, so it must not be a problem" is not a valid argument. If you've ever tried to remove a plastic bag that was half-buried in sand, you would know. That bag could sit there for hundreds of years without degrading.

My point is that it's better to not have new bags/material made at all. Repurpose something that was already made and used for other purposes, and you lessen the footprint. It doesn't have to be cotton, the woven bags made from recycled plastic are quite durable and long-lasting. In my case, I do have cotton shopping bags, but they're all hand-me-downs from family, I would never buy a brand-new one.

If you want something made from upcycled sail cloth or similar repurposed materials, there are a number of companies who will happily sell you some, including customization.

Remember, it's "reduce, reuse, recycle, in that order.

[smileysteve]

Brag, I've been reusing the same backpack from high school for over a decade. It carries about 30l or 16lbs of fluids, I've had the zippers repaired once, and I probably use it at least one a week.

[lstodd]

This. I shop with a 10 year old Deuter, and although it looks worn, I expect it to last at least another 10 years.

It is also healthier for your spine than an equivalent bunch of bags, and keeps hands free. What's not to like?