4 ms·

People still view them as disposable though. Public policy necessarily interacts with real people, and those interactions are currently a net negative. You mig

by hansvm 1y ago

People still view them as disposable though. Public policy necessarily interacts with real people, and those interactions are currently a net negative. You might fix that by encouraging properly reusable bags (e.g., by banning even the rugged bag sales), but that's problematic too. By many metrics, with normal usage, they're worse than the disposable bags people used to use (the break-even point is linear in the number of days between shopping trips, and unless we also encourage more frequent short _walks_ or something to the store you also have the issue of car-related expenses, not to mention that if your diet is largely meats and other animal products as is common in the US, walking is actually more carbon intensive than taking an EV the same distance (biking blows them both out of the water in efficiency)).

cwillu 1y ago
Got a breakdown on the walking calculation anywhere? I find myself suspicious of the argument, not least because such walking will likely displace exercise and idle time elsewhere.
- hansvm 1y ago
  Coming from an assumption of being overweight or otherwise needing extra exercise in your day the argument completely falls apart. In the US, on average, you'd have a ton of benefits encouraging more walking, likely reducing net CO2-equivalent production in the process (smaller bodies require less maintenance energy). In a country like Vietnam or Japan (or when applied at an individual level rather than a societal level, each individual weighing whether they actuall need more exercise at the moment) we can get back to the simple assumption of walking requiring extra calories (which you'll eventually eat due to hunger and some sort of weight homeostasis) and just running the numbers (all slightly conservative for "typical" scenarios, favoring beef over gasoline to mildly steelman the argument): - Beef produces something like 48 lbs of CO2 equivalent emissions per pound - Beef is something like 1200 calories per pound - Walking burns something like 90 calories per mile This directly gives 3.6lb of CO2 equivalent emissions per mile. Under a homeostasis assumption, none is sequestered on average long-term in the person doing the walking, though actual emissions could be slightly higher or lower when taking into account the relative greenhouse impact of human emissions in response to that digestion/exercise (but this is somewhat negligible compared to a cow's methane production). Even pretty crappy cars in city driving conditions can achieve 20mpg, which is only 1.02lb of CO2 equivalent emissions per mile, 3.5x better. Most people aren't eating pure beef, but the break-even point (compared to that hypothetical extremely shitty car; the argument favors gasoline even more with more modern vehicles) is 28% of your calorie budget (assuming all other inputs have zero greenhouse impact). Chicken is better at only 1.6lb of emissions per mile of walking, with a break-even point at 63%. Cheese and butter are _slightly_ better still. Nearly all animal products are much worse than gasoline, and basically any diet made from >=70% animal products (denominated in calories) will have higher emissions than a 20mpg car and driving habit. If you compare it to more typical cars (my car is dirt cheap, from 2008, and still gets 30mpg city even after 17 years of wear and tear), the break-even point is much worse. Counter-arguments include that the carbon impact of a car is much higher than just its gasoline consumption, but if you work through the math everything else put together is a rounding error compared to the gas over the lifetime of a vehicle (still 5-15%, but it doesn't substantially impact anything I've said so far).
  - wrigby 1y ago
    I was curious what these numbers look like if people get their extra calories from carbs instead of animal products: - A 100g cooked serving of pasta has 131 calories [1] - This random website claims that a 100g serving of pasta generates 0.58 lb CO2 equivalent emissions - To get 90 calories we need ~69g of pasta - This gives 0.4lb CO2e per mile when walking under pasta power I'm not sure if the CO2 estimation for pasta is using a cooked weight or a dry weight, so I chose the worst-case scenario. If that CO2e number is applied to 100g of _dry_ pasta, the numbers get way better. 1: https://fdc.nal.usda.gov/food-details/169728/nutrients https://fdc.nal.usda.gov/food-details/169728/nutrients 2: https://www.co2everything.com/co2e-of/pasta https://www.co2everything.com/co2e-of/pasta
sfasdfh123 1y ago
>People still view them as disposable though No way this is true, not when the bag costs about 30% of what I usually buy per trip.
- bluefirebrand 1y ago
  I promise you this is true Especially with delivery services where a store will deliver your order to your door, you just keep accumulating more and more of those "reusable" bags. But the reality is that you really only need so many reusable bags, so when you keep getting more you have to do something with them Bags should have a deposit and a "return excess bags for a refund" system like bottles do Otherwise they are going to go to landfills, no question
  - rectang 1y ago
    I have only ordered groceries once because of all the "reusable" bags I got stuck with. Those things are incredibly durable. I have two as my backup grocery bags and I've been using the same ones for nearly a decade.
  - jay_kyburz 1y ago
    Your country is just a little behind. Groceries and takeout food comes in paper bags now.
- dragonwriter 1y ago
  > No way this is true, not when the bag costs about 30% of what I usually buy per trip. The price is normally the legislated minimum, 10¢. So your average shopping trip is ~33¢?
  - frosted-flakes 1y ago
    Reusable shopping bags cost about $10-$15. No one is buying them frivolously. I think the issue here is one of semantics. The so-called "reusable" bags you're talking about are still classified as single-use plastics. If you look at BC as an example, where ALL single-use plastic bags at checkouts are banned, people have adapted just fine. In some stores (like restaurants) you can buy paper bags for 25¢, but generally people either don't bother with bags at all and simply load things directly into their cars, or they bring their own bags or baskets. Now, pretty much the only litter I regularly see is paper coffee cups or candy wrappers. Bags have disappeared, and bottles and cans usually collected for the deposit.
whyenot 1y ago
Your are asserting a lot of facts here. Please provide some references so that those of us who are interested can learn more.
- hansvm 1y ago
  - The walking thing you can mostly calculate yourself if you only examine particular foods, but here's some study looking at the dietary impact in practice averaged across a country (walking has comparable emissions to a 22mpg car trip in developed countries) [0]. - For cotton reusable bags (very common for all sorts of reasons; all my reusable bags are cotton and not because of any particular intentional selection), you need 50+ trips to the store to hit a break-even point [1] in greenhouse emissions. Similarly with the 50x thicker plastic bags stores in CA sell compared to disposable shopping bags. That's 1-2yrs for the break-even point with weekly or biweekly shopping trips, worse if your usage distribution is temporally nonuniform (e.g., owning 5 bags but sometimes only using only 1-3 for slightly more frequent shopping trips and occasionally using all 5). Properly reusable bags are likely worth it, but it's not an immediate or obvious win unless you use them regularly and they're sturdy enough to not wear out too quickly (enough material is involved and the timescales are long enough that you should also consider the impact of the disposal method and a number of other things). - Some of the other points like linearity in the number of days between shopping trips should be obvious. I'll leave investigating everything else as an exercise for the reader. [0] https://www.nature.com/articles/s41598-020-66170-y https://www.nature.com/articles/s41598-020-66170-y [1] Not "source" so much as a summary of sources, so I referenced the smallest number in the article to give the argument more weight: https://www.cnn.com/2023/03/13/world/reusable-grocery-bags-cotton-plastic-scn https://www.cnn.com/2023/03/13/world/reusable-grocery-bags-c...
  - estebank 1y ago
    You are making the baseline assumption that the reason for reusable bags is to reduce greenhouse emissions, instead of reducing the number of plastic bags being discarded in public areas causing negative externalities like affecting wildlife. Heavier plastic bags have a greater chance of lasting beyond a single shop trip to make it long enough to be reused at the very least as a garbage bag. Paper bags desintegrate easily if thrown in the trash and are trivially recyclable. I do think that we need to meet people where they are at, you can't expect people to over night start bringing a classic trolley and/or canvas bags to a local shop if they don't have a shop to walk to or dont have a way to keep a bag on themselves at all times, but we can slowly nudge people towards desirable behavior. And that's what charging for bags does.

by hansvm 1y ago

cwillu 1y ago

Got a breakdown on the walking calculation anywhere? I find myself suspicious of the argument, not least because such walking will likely displace exercise and idle time elsewhere.

hansvm 1y ago
Coming from an assumption of being overweight or otherwise needing extra exercise in your day the argument completely falls apart. In the US, on average, you'd have a ton of benefits encouraging more walking, likely reducing net CO2-equivalent production in the process (smaller bodies require less maintenance energy). In a country like Vietnam or Japan (or when applied at an individual level rather than a societal level, each individual weighing whether they actuall need more exercise at the moment) we can get back to the simple assumption of walking requiring extra calories (which you'll eventually eat due to hunger and some sort of weight homeostasis) and just running the numbers (all slightly conservative for "typical" scenarios, favoring beef over gasoline to mildly steelman the argument): - Beef produces something like 48 lbs of CO2 equivalent emissions per pound - Beef is something like 1200 calories per pound - Walking burns something like 90 calories per mile This directly gives 3.6lb of CO2 equivalent emissions per mile. Under a homeostasis assumption, none is sequestered on average long-term in the person doing the walking, though actual emissions could be slightly higher or lower when taking into account the relative greenhouse impact of human emissions in response to that digestion/exercise (but this is somewhat negligible compared to a cow's methane production). Even pretty crappy cars in city driving conditions can achieve 20mpg, which is only 1.02lb of CO2 equivalent emissions per mile, 3.5x better. Most people aren't eating pure beef, but the break-even point (compared to that hypothetical extremely shitty car; the argument favors gasoline even more with more modern vehicles) is 28% of your calorie budget (assuming all other inputs have zero greenhouse impact). Chicken is better at only 1.6lb of emissions per mile of walking, with a break-even point at 63%. Cheese and butter are _slightly_ better still. Nearly all animal products are much worse than gasoline, and basically any diet made from >=70% animal products (denominated in calories) will have higher emissions than a 20mpg car and driving habit. If you compare it to more typical cars (my car is dirt cheap, from 2008, and still gets 30mpg city even after 17 years of wear and tear), the break-even point is much worse. Counter-arguments include that the carbon impact of a car is much higher than just its gasoline consumption, but if you work through the math everything else put together is a rounding error compared to the gas over the lifetime of a vehicle (still 5-15%, but it doesn't substantially impact anything I've said so far).
- wrigby 1y ago
  I was curious what these numbers look like if people get their extra calories from carbs instead of animal products: - A 100g cooked serving of pasta has 131 calories [1] - This random website claims that a 100g serving of pasta generates 0.58 lb CO2 equivalent emissions - To get 90 calories we need ~69g of pasta - This gives 0.4lb CO2e per mile when walking under pasta power I'm not sure if the CO2 estimation for pasta is using a cooked weight or a dry weight, so I chose the worst-case scenario. If that CO2e number is applied to 100g of _dry_ pasta, the numbers get way better. 1: https://fdc.nal.usda.gov/food-details/169728/nutrients https://fdc.nal.usda.gov/food-details/169728/nutrients 2: https://www.co2everything.com/co2e-of/pasta https://www.co2everything.com/co2e-of/pasta

sfasdfh123 1y ago

>People still view them as disposable though No way this is true, not when the bag costs about 30% of what I usually buy per trip.

bluefirebrand 1y ago
I promise you this is true Especially with delivery services where a store will deliver your order to your door, you just keep accumulating more and more of those "reusable" bags. But the reality is that you really only need so many reusable bags, so when you keep getting more you have to do something with them Bags should have a deposit and a "return excess bags for a refund" system like bottles do Otherwise they are going to go to landfills, no question
- rectang 1y ago
  I have only ordered groceries once because of all the "reusable" bags I got stuck with. Those things are incredibly durable. I have two as my backup grocery bags and I've been using the same ones for nearly a decade.
- jay_kyburz 1y ago
  Your country is just a little behind. Groceries and takeout food comes in paper bags now.
dragonwriter 1y ago
> No way this is true, not when the bag costs about 30% of what I usually buy per trip. The price is normally the legislated minimum, 10¢. So your average shopping trip is ~33¢?
- frosted-flakes 1y ago
  Reusable shopping bags cost about $10-$15. No one is buying them frivolously. I think the issue here is one of semantics. The so-called "reusable" bags you're talking about are still classified as single-use plastics. If you look at BC as an example, where ALL single-use plastic bags at checkouts are banned, people have adapted just fine. In some stores (like restaurants) you can buy paper bags for 25¢, but generally people either don't bother with bags at all and simply load things directly into their cars, or they bring their own bags or baskets. Now, pretty much the only litter I regularly see is paper coffee cups or candy wrappers. Bags have disappeared, and bottles and cans usually collected for the deposit.

whyenot 1y ago

Your are asserting a lot of facts here. Please provide some references so that those of us who are interested can learn more.

hansvm 1y ago
- The walking thing you can mostly calculate yourself if you only examine particular foods, but here's some study looking at the dietary impact in practice averaged across a country (walking has comparable emissions to a 22mpg car trip in developed countries) [0]. - For cotton reusable bags (very common for all sorts of reasons; all my reusable bags are cotton and not because of any particular intentional selection), you need 50+ trips to the store to hit a break-even point [1] in greenhouse emissions. Similarly with the 50x thicker plastic bags stores in CA sell compared to disposable shopping bags. That's 1-2yrs for the break-even point with weekly or biweekly shopping trips, worse if your usage distribution is temporally nonuniform (e.g., owning 5 bags but sometimes only using only 1-3 for slightly more frequent shopping trips and occasionally using all 5). Properly reusable bags are likely worth it, but it's not an immediate or obvious win unless you use them regularly and they're sturdy enough to not wear out too quickly (enough material is involved and the timescales are long enough that you should also consider the impact of the disposal method and a number of other things). - Some of the other points like linearity in the number of days between shopping trips should be obvious. I'll leave investigating everything else as an exercise for the reader. [0] https://www.nature.com/articles/s41598-020-66170-y https://www.nature.com/articles/s41598-020-66170-y [1] Not "source" so much as a summary of sources, so I referenced the smallest number in the article to give the argument more weight: https://www.cnn.com/2023/03/13/world/reusable-grocery-bags-cotton-plastic-scn https://www.cnn.com/2023/03/13/world/reusable-grocery-bags-c...
- estebank 1y ago
  You are making the baseline assumption that the reason for reusable bags is to reduce greenhouse emissions, instead of reducing the number of plastic bags being discarded in public areas causing negative externalities like affecting wildlife. Heavier plastic bags have a greater chance of lasting beyond a single shop trip to make it long enough to be reused at the very least as a garbage bag. Paper bags desintegrate easily if thrown in the trash and are trivially recyclable. I do think that we need to meet people where they are at, you can't expect people to over night start bringing a classic trolley and/or canvas bags to a local shop if they don't have a shop to walk to or dont have a way to keep a bag on themselves at all times, but we can slowly nudge people towards desirable behavior. And that's what charging for bags does.