Plastic pollution in our seas

[a64pilot]

A quick google will find all kinds of biodegradable plastic bags and other plastics.
https://greenpaperproducts.com/biode...hoCtP0QAvD_BwE
Ever seen the plastic packing peanuts that aren’t plastic? They are some form of starch, put them in water and they 100% dissolve.

We don’t have to give up anything to get rid of single use plastics that aren’t biodegradable, we choose not to for I’m sure economic reasons.

[Lake-Effect]

Originally Posted by GordMay

A 2018 Danish study, looking at the number of times a bag should be reused, before being used as a bin liner and then discarded, found that:
polypropylene bags (most of the green reusable bags found at supermarkets) should be used 37 times
paper bags should be used 43 times
cotton bags should be used 7,100 times.
➥ https://www2.mst.dk/Udgiv/publicatio...93614-73-4.pdf

A UK study, which only considered the climate change impact, found that to have lower global warming potential than single-use plastic bags:
paper bags should be used three times
low-density polyethylene bags (the thicker plastic bags commonly used in supermarkets) should be used four times
non-woven polypropylene bags should be used 11 times
cotton bags should be used 131 times.
➥ https://assets.publishing.service.go...11buan-e-e.pdf

We've been using the same set of 3 or 4 reusable shopping bags for at least 5 years. I can't recall any that 'failed' or wore out yet.

[svenskflicka]

Originally Posted by a64pilot

A quick google will find all kinds of biodegradable plastic bags and other plastics.
https://greenpaperproducts.com/biode...hoCtP0QAvD_BwE
Ever seen the plastic packing peanuts that aren’t plastic? They are some form of starch, put them in water and they 100% dissolve.

We don’t have to give up anything to get rid of single use plastics that aren’t biodegradable, we choose not to for I’m sure economic reasons.

Almost all of these "compostable" are made of PLA and carry the caveat that they are compostable in an industrial composting facility.

Outside of these near perfect composting conditions they basically break down into microplastics just like the rest.

https://www.bbc.com/future/article/2...plastic-crisis

[Mike OReilly]

Originally Posted by GordMay

I suspect you may well be right. It's a complicated issue, which isn't likely to have simple solutions.

A 2018 Danish study, looking at the number of times a bag should be reused, before being used as a bin liner and then discarded, found that:
polypropylene bags (most of the green reusable bags found at supermarkets) should be used 37 times
paper bags should be used 43 times
cotton bags should be used 7,100 times.
➥ https://www2.mst.dk/Udgiv/publicatio...93614-73-4.pdf

A UK study, which only considered the climate change impact, found that to have lower global warming potential than single-use plastic bags:
paper bags should be used three times
low-density polyethylene bags (the thicker plastic bags commonly used in supermarkets) should be used four times
non-woven polypropylene bags should be used 11 times
cotton bags should be used 131 times.
➥ https://assets.publishing.service.go...11buan-e-e.pdf

Exactly the point Gord. To make reusable bags more environmentally friendly than plastic they need to be resused hundreds to thousands of times. I'm not aware of research looking at how often these bags are re-used before wearing out or getting lost, or even how many reusable bags we all collect. I bet that a real-world analysis would reveal they are far less beneficial, and quite likely worse for the environment over all.


I'm all for sound environmental initiatives, but too often these actions are more symbolic than actually beneficial.

[a64pilot]

Call me a fool but how does the thousands of plastic bags that we would have thrown into the trash be better for the environment than the cotton bags that we don’t throw into the trash?
And even when they do go into the trash, cause nothing last forever, cotton is certainly biodegradable, never heard of anyone finding cotton bags in a whale etc.
Before you say thousands is overstating it, I bet if we used those little bags we would have at least 20 of them every shopping trip.

[KnotToday]

Check out blueland.com
I purchased the kit last year and absolutely love it.

As far as cotton bags vs plastic, check out lifewithoutplastic.com I have two of the large bags and wish I had more. Interesting site if you like to think outside the box on a couple items. I started to refuse single use two years ago.

[Mike OReilly]

Originally Posted by a64pilot

Call me a fool but how does the thousands of plastic bags that we would have thrown into the trash be better for the environment than the cotton bags that we don’t throw into the trash?
And even when they do go into the trash, cause nothing last forever, cotton is certainly biodegradable, never heard of anyone finding cotton bags in a whale etc.
Before you say thousands is overstating it, I bet if we used those little bags we would have at least 20 of them every shopping trip.

If a full life-cycle analysis is applied, it requires the number of re-uses indicated to make reusable bags better than plastic. How and why this is the case could be read in the analysis. Likely has to do with the resource requirement to produce, the cost to transport and distribute, and the challenge of final disposal among many other facts.



That's not to say these studies are definitive. There is far too few to be so certain. But the point remains that to be net-beneficial, a reusable bag must be reused a substantial number of times. I am skeptical that most achieve this threshold, but a good study on this question could help answer the question.

[Exile]

I certainly commiserate with the growing consensus about single use plastics and specifically plastic bags, but solutions are never as simple as people often want to believe. As far as politicians go, they're often not any smarter than the people who elected them, and too often respond to constituents who shout the loudest but aren't necessarily well informed.

It's somewhat ironic that the Swedish inventor of the plastic bag was justifiably considered an environmental savior because his invention in 1959 would save the felling of trees used to make the then ubiquitous paper bags. The only problem is he intended plastic bags to be reusable, and never contemplated they would be disposed of after a single use. (2:57)

https://www.youtube.com/watch?v=DQW5w9yAWgE

[svenskflicka]

Originally Posted by a64pilot

Call me a fool but how does the thousands of plastic bags that we would have thrown into the trash be better for the environment than the cotton bags that we don’t throw into the trash?
And even when they do go into the trash, cause nothing last forever, cotton is certainly biodegradable, never heard of anyone finding cotton bags in a whale etc.
Before you say thousands is overstating it, I bet if we used those little bags we would have at least 20 of them every shopping trip.

I'm with you on this one. We use the reusable bags. We have four decent sized ones and have replaced 10-15 plastic bags per week, for 6 years now.

That aside, no one is going to convince me that drilling oil and converting it into 1k plastic bags is better for the environment that growing cotton and making 1 bag....

[transmitterdan]

Cotton and soybeans pull massive amounts of nutrients from the soil. So most cotton is grown using lots of nitrogen (ammonium nitrate or anhydrous ammonia) as fertilizer and of course pesticides. Nothing humans do is free of environmental impact.

[svenskflicka]

I didnt say cotton was free of impact. Oil requires vast resources to explore and drill and contaminates our soil and water when spilled. No way 1000 bags that will never disappear is better than 1 bag that will decompose readily.

Originally Posted by transmitterdan

Cotton and soybeans pull massive amounts of nutrients from the soil. So most cotton is grown using lots of nitrogen (ammonium nitrate or anhydrous ammonia) as fertilizer and of course pesticides. Nothing humans do is free of environmental impact.

[Exile]

Originally Posted by svenskflicka

I didnt say cotton was free of impact. Oil requires vast resources to explore and drill and contaminates our soil and water when spilled. No way 1000 bags that will never disappear is better than 1 bag that will decompose readily.

The point of the BBC video, along with ones others have been making, is that it's the disposal of the plastic bag after a single or only a few uses that's the problem, not necessarily the bag itself. As its original inventor intended, a plastic bag made from petroleum may in fact have less of an overall environmental than ones made out of paper or cotton, but only if they're reused. Not that I hold out much hope for getting people to change their ways, but proposed remedies should be fully informed so as to avoid unintended impacts that may turn out to be worse for the environment than the problem they're trying to address.

[KnotToday]

I use a 4Ocean Cleanup Tote as a vegetable hammock. They really carry the weight when provisioning. They are 18x30 I think. I have a couple carabiners and smaller hammocks hanging to the inside and that gives easy access to everything with smaller items near the top. I have four of these bags for different purposes.

[Mike OReilly]

Just to be clear, I completely believe the use of reusable bags can definitely be a net-benefit to the environment. I also believe it can be a net-benefit to own and travel via modest sailing vessel. But in both cases the actual environmental impact depends on how one uses these things.

In the bag case it relies on how the reusable bag is manufactured, distributed, used and reused, and then disposed of. Given the high number of reuses needed to make reusable bags fall on the plus side, I am dubious as to their benefits. Just like a cruising sailboat can be a net plus if one sails most of the time. How many do?

Interestingly, the transition from paper to plastic bags was a case study used in my university environmental assessment program. Yes... plastic bags were touted as a positive environmental shift. In the life-cycle analysis we conducted the outcome suggested otherwise, but the train was rolling at that point and we got rid of paper bags in favour of plastic.

[Cadence]

Originally Posted by Mike OReilly

Just to be clear, I completely believe the use of reusable bags can definitely be a net-benefit to the environment. I also believe it can be a net-benefit to own and travel via modest sailing vessel. But in both cases the actual environmental impact depends on how one uses these things.

In the bag case it relies on how the reusable bag is manufactured, distributed, used and reused, and then disposed of. Given the high number of reuses needed to make reusable bags fall on the plus side, I am dubious as to their benefits. Just like a cruising sailboat can be a net plus if one sails most of the time. How many do?

Interestingly, the transition from paper to plastic bags was a case study used in my university environmental assessment program. Yes... plastic bags were touted as a positive environmental shift. In the life-cycle analysis we conducted the outcome suggested otherwise, but the train was rolling at that point and we got rid of paper bags in favour of plastic.

Saving the forests and polluting the planet. That was driving by oil money.