The battle of the bags

I have been seeing a lot recently about the relative merits of paper vs plastic. Having been alerted to the huge issues with plastic pollution, the general public seems to be convinced that wholesale conversion to paper or cardboard packaging is the answer. Purely from the perspective of end-of-life disposal, this is a perfectly logical switch because paper is biodegradable and plastic isn’t. But life isn’t really that simple, is it?

There are various studies which show that the carbon footprint of a plastic bag is way smaller than a paper bag, For example, a report published by the UK Environment Agency in 2011 examined a variety of types os shopping bags:

• a conventional, lightweight carrier made from high-density polyethylene (HDPE)

• a paper carrier;

• a “bag for life” made from low-density polyethylene (LDPE);

• a heavier more durable bag, often with stiffening inserts made from non woven polypropylene (PP); and

• a cotton bag

And here is a summary of some of their results:2019-06-23Source: Environment Agency (2011) Life cycle assessment of supermarket carrier bags: a review of the bags available in 2006

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Paper vs Cotton

As you can see, according to this data, you have to use a paper bag three times and a cotton bag 131 times for them to have the same ‘global warming potential’ as a ‘normal’ plastic carrier bag used just once. Of course, there are all sorts of complicating factors – if you make a cotton bag out of scraps rather than virgin fabric, then that’s an entirely different matter. Indeed, using waste fabric to make bags could probably be considered to have an overall positive impact on the environment rather than a negative one. But what this does show, is that paper bags may not be the a great solution, and it doesn’t begin to take into consideration what a polluting process paper production can be (you can read about the environmental impact of paper here).

However, the data in the Environment Agency Report are a few years out of date and SNS (Nordic Forest Research) recently published a report outlining the climate benefits of forests. It turns out that actively growing young trees assimilate much more carbon than mature trees, so managed forests from which timber is extracted do more to reduce atmospheric carbon than old forests. There are other issues related to conservation and biodiversity, but the fact remains that it’s good to use wood.

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Plastic or not?

Some of the manufacturers, processors and producers who need to use some form of packaging do seem to be exploring different options. After all, there are all sorts of materials available and new technology is delivering various solutions with, apparently, better environmental credentials. For example, for a while now I’ve been buying my coffee from a small company that supports small producers and uses no plastic in their packaging. Last month, however, the coffee arrived not in a paper pack, but in something that looked like plastic. Why? Well, The Roasting House explained their change as follows:

Those of you who have ground coffee will have been receiving the Natureflex packaging for a while now but if you have whole bean it may come as a shock when you get the package so first of all I want to reassure you that it’s no plastic!

We use Natureflex for our ground coffee as it preserves the oils in the coffee and keeps it fresher. The whole bean coffee doesn’t lose freshness as quickly so we’ve sent it in paper for a while for you to transfer to your own air tight container. However we’re starting to move more towards using the Natureflex and less paper in our sister business Plastic Free Pantry. It provides a good air and moisture barrier and is less prone to breakages. But crucially it has a lower carbon impact than paper. The carbon impact of production for the unlined type of Natureflex that we use is lower than plastic, and the manufacturers then use off-setting to make it carbon neutral.

It is compostable in home conditions and will break down in soil and marine environments (although obviously don’t chuck it in the sea or litter it!). If you have a compost bin, it will break down in 12-16 weeks. Alternatively you can shred it and bury it in your garden. If you can’t compost it yourself, you can return it to us for refilling or composting.

So, it turns out that doing the right thing is complicated and that avoiding one problem (e.g. plastic pollution) can lead to another (e.g. carbon dioxide emissions). What we really need is institutional change in terms of reducing the use of ALL resources and I encourage you to lobby manufacturers, retailers and politicians to this end, but it’s also good to take personal responsibility, so reuse what you already have (whatever it’s made of) and REFUSE grocery/produce bags wherever possible.

 

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