[_petronius]

Although "environmentally friendly" is not strictly equal to "minimum possible GHG footprint". The plastic bag may have a lower carbon footprint, but it isn't going to biodegrade as quickly, and may end up turning into microplastics that persist for a long time.

[copirate]

The linked chart about grocery bags[1] is not only about GHG footprint:

> Environmental impact is measured over a full life-cycle analysis (LCA) across the following metrics: greenhouse gas emissions, ozone depletion, human toxicity (cancer effects), human toxicity (non-cancer effects), photochemical ozone formation, ionizing radiation, particulate matter, terrestrial acidification, terrestrial eutrophication, marine eutrophication, ecosystem toxicity, resource depletion (fossil), resource depletion (abiotic), and water resource depletion.

[1] https://ourworldindata.org/grapher/grocery-bag-environmental...

[gruez]

>The plastic bag may have a lower carbon footprint, but it isn't going to biodegrade as quickly, and may end up turning into microplastics that persist for a long time.

What you described is a non-issue if the bag is disposed of properly. Presumably you, as a environmentalist can be relied upon to do that.

[em-bee]

that's only true if every plastic bag user disposes of the bags properly. part of the problem of using plastic bags is that it increases the demand. i specifically ask for less plastic bags in the produce section in order to teach the sales person that it is not necessary to have each item individually wrapped as is the custom here. i want them to apply that to other customers and so reduce the use of bags even more.

[b3morales]

Could you elaborate on what proper disposal looks like?

[gruez]

landfill (properly engineered and regulated[1]) or incineration.

[1] https://www.ecfr.gov/current/title-40/chapter-I/subchapter-I...

[b3morales]

Interesting, thanks.

[akomtu]

In the future there will be an acid-like substance used to safely dissolve almost anything, except maybe metals and stones.

[hutzlibu]

We already have them since quite a while, also to dissolve most metals and stones. But producing them in the required quantities would be kind of out of proportion to use it for garbage disposal. And disposing garbage in acid means still having lots of garbage basins with acid. You might want to check out some chemistry.

[jrajav]

I also wondered this - initially I saw that the chart linked had a "Lifecycle Analysis" and so I nodded and went on my way thinking that disposal had been accounted for.

I'm glad you brought it up, because upon looking at the study the chart is based on, it seems hopelessly optimistic - it accounts for several end-of-life scenarios but they are all 'good' disposals performed after plastic collection, like recycling or incineration. Zero accounting for accidental or incompetent sending to landfills, which indeed seems the main issue with plastic bags.

(The study is also specific to Denmark, where perhaps disposal programs are more reliable than they are in the US.)

https://www2.mst.dk/Udgiv/publications/2018/02/978-87-93614-...

[AstralStorm]

The point is to reuse for ages a tough plastic bag rather than use single use bags.

[leereeves]

I have 5 reusable bags that I've used for a few years.

That means I've used them maybe 100 times. Now they're starting to fall apart, and soon I'll need new ones.

I wonder, since they're much heavier and clearly use a lot more plastic, whether I would have used less plastic with the disposable ones.

[liminvorous]

The breakeven point seems to be around 50-100 uses depending on the exact kind of reusable bag, so you’re probably winning: https://ourworldindata.org/grapher/grocery-bag-environmental...

[leereeves]

I never would have imagined the environmental impact of cotton bags was that high. It would take me several lifetimes to get 7000 uses.

[ZeroGravitas]

This very similar to the "if you wash recycling in water heated via coal burn generated electricity then it creates CO2" argument.

Okay, let's stop burning coal then, because we use electricity for a lot more things than just recycling.

Similarly, if cotton is that bad for the environment, maybe we need to fix that generally rather than just switch to disposable plastic bags for this one minor use case?

https://www.worldwildlife.org/industries/cotton

[rini17]

Nobody does napkin math anymore? One use bag is about 2-10 grams of plastic. 100x that is 200 grams to 1kg.

[leereeves]

The math is easy, but I don't have a tiny scale or specs on the weight of either bags. Where did you get 2-10 grams?

[rini17]

In stores we have selfservice weighting scales for fruits and veggies that print the barcode. There's an option "with one-use bag/without bag" and the one-use bag option subtracts 2 grams.

[Jill_the_Pill]

They do make cloth reusables

[dqv]

The cloth reusables are a little more harsh on the environment for initial acquisition, but I like that if they get holes, I can patch them. I'm not sure how feasible that is with the thicker plastic bags, and a cursory search doesn't bring anything up, but it's worth looking into patching the plastic bags.

[em-bee]

duct tape, but now we need to take into account the environmental impact of that.

though the biggest problem with reusable plastic bags is the weakness of the handles. i'd rarely get more than a dozen uses out of a plastic bag before the handle rips. and that is not as easily to fix because of the stresses involved.

also, i feel the math is off, because cloth bags are a lot stronger and they get uses that no plastic bag is even designed for. so the reality is that even if i use plastic bags for shopping, i'd have a cloth bag anyways for other needs. and if i have it already, then using it more comes with zero additional impact.

plastic bags only have less impact on the environment than the cloth bags that i don't already own.

[Jill_the_Pill]

Well ok, in the "already have it" vein, how about just taking stuff home in the boxes that the store receives its goods in? Ours has a pile near the registers. Then we break them down and use them as sheet mulch.

[nyokodo]

> if i have it already, then using it more comes with zero additional impact.

Except using it more means more wear and tear which means replacing it sooner. So unfortunately it doesn’t make the math easier.