How effective is the ban on single-use plastic straws and bags?

Recently, Australia has had a wave of bans on plastic straws and plastic bags from being available at many bars, restaurants and supermarkets. The main objective appears to be to reduce the amount of plastic that ends up in the ocean (the famous Great Pacific Garbage Patch comes to mind). This plastic often breaks down in to microplastic – small particles that don’t further break down and end up being eaten by small fish, thus entering the food chain. A laudable goal to be sure.

However, given what I know about the relative effectiveness of interventions, I wonder if this is the most effective (or even relatively effective) at reducing plastic relative to other things one can do. I will note that I already have pre-existing opinions on this, but will do my best to make an unbiased assessment.

There are two ways to look at this. One is to consider the actions of an individual. In other words, how effective is it for me to stop using plastic straws and bags relative to doing some other thing. The other way is to consider it from the perspective of a business or other actor such as a campaigner who is seeking to get businesses stop stocking such items. I will focus on the first one. Examining the impact of working to reduce plastic bag and straw use in general relative to reducing plastic use in other cases seems hard and not well suited for a brief examination.

First, I will estimate the volume of plastic used in these two cases by the average Australian.

Plastic use from single-use plastic bags

Woolworths [an Australian supermarket] currently gives out more than 3.2 billion single-use HDPE plastic bags every year, and according to a 2009 study, about 1 per cent of those, or 30 to 40 million, find their way into the environment. [From here]

Woolworths isn’t the only source of plastic bags in Australia, but it’s a good start. We can probably assume that the 1% figure of these bags getting to the environment is representative of the bags as a whole. A fact sheet by Keep Queensland Beautiful states that Australians use 4 billion plastic bags each year. This doesn’t seem to agree with the previous stat, as it’s unlikely that Woolworths accounts for 80% of the plastic bag distribution.

For arguments sake, let’s assume 4 billion bags per year with 1% of those reaching the environment. That’s 40 million bags per year, or about 1.5 per Australian. Assuming you’re consuming about the average (or were before the bans and public pressure), switching from single-use plastic bags to an alternative should mean 1.5 less plastic bags in the environment per year.

I found it surprisingly hard to find a value for the weight of a single-use plastic bag. In lieu of just weighing one myself, the best I could do was this document from a website called fighttheplasticbagban.com which gave a value of 9.3 grams. This actually seems kind of high to me. This results in a value of 13.95 grams in the environment per person per year. I’m very open to revising this if someone can find a more reputable estimate.

I will also note that alternatives to single-use plastic bags aren’t necessarily better for the environment, and could actually be worse. Just one example of this is that a ban on plastic bags results in an increase in bin liner plastic sales. This is the same kind of mindless optimism I see in other areas including fair trade, organic food, and some renewable energies. Just because something sounds good, doesn’t mean it is better in all aspects.

A review of the ACT ban in 2012 found that bin liner sales had indeed increased by 31 per cent a year after the ban came into place.

But a second review in 2014 found that sales had settled back down to pre-ban levels. [from here]

Plastic use from single-use plastic straws

Australians use around 10 million plastic straws each day, or 3.65 billion per year. For lack of a figure I’ll assume 1% of these end up in the environment as well, giving a figure of 36.5 million. This gives about 1.4 straws less in the environment per person per year.

It was also hard to find an estimate of weight for plastic straws, but this paper suggests around 0.45 grams, or 0.63 grams in the environment per person per year. This gives a total of 14.58 grams in the environment per person per year from the combined sources.

We’ve examined the effectiveness of a ban on single-use plastic bags and straws. Let’s now look at two alternatives.

Alternative #1 – Veganism

A vegan lifestyle is well-known to significantly reduce ones’ impact on the environment in general (as well as farmed animal suffering), but lets’ suppose we are specifically interested in plastic. When one thinks of the Great Pacific Garbage Patch, images of plastic bottles and bags probably comes to mind. However, 46% of the total trash is estimated to be fishing nets (much of which is made of plastic), with the majority of the rest being miscellaneous fishing gear, not consumer plastics.

Accepting this, it still seems hard to estimate the relative impact of purchasing fish vs consumer plastics. With consumer plastics we can easily measure volume, however to estimate the impact of fishing we would need to calculate the volume of nets used per person per year, as well as the relative rate of loss to ocean of consumer plastics vs fishing gear. Simplistically, one could argue that since the volume of plastic in the ocean is mostly from fishing gear, eliminating fish from ones’ diet should have a greater impact than eliminating consumer plastics.

One estimate suggests 640,000 tonnes of fishing gear is left in the ocean per year. That’s an average of 84 grams per person per year (globally). However Australians consume around 28 kg of fish per year as of 2013, while average consumption globally was 16.4 kg in 2005. Assuming the fish Australians consume is about as plastic-polluting as the global average, we should multiply our 84 grams per person by 1.7, giving 143 grams.

Eliminating your use of plastic straws and bags might seem easier than adopting a plant-based diet for many people (though I’d argue it’s easier than you probably think), but you’d be kidding yourself if you thought you were having a big impact by doing only the former.

A cautionary note

Whenever I talk about the environmental benefits of a vegan lifestyle, I feel compelled to tell my cautionary tale. I believe it is possible that advocating for the environmental benefits of veganism could actually increase farmed animal suffering. In short, this is because the primary cause of environmental damage from eating animals is from red meat. If this causes people to eat less red meat and more poultry or fish, they would be causing more sentient minds to suffer, since it takes many chickens or fish to get the same volume of food as a cow.

This case is a little different, since I’m talking about the damage of fishing, but I would still encourage anyone convinced by my argument to try veganism rather than just eat no fish*.

Alternative #2 – Reducing other plastic use

It seems likely to me that the plastic from straws and bags is only a small part of what a consumer consumes, even if we ignore fishing nets. One has to wonder whether reducing their plastic use in other areas could have a vastly greater impact.

As of 2016, Australia produces around 3 million tonnes of plastic per year. Around 130,000 tonnes of this plastic is estimated to end up in the ocean each year. Interestingly, this is 4 times the proportion of plastic from bags that ends up in the environment. This gives 5.4 kg of plastic in the ocean total per person per year. I don’t know the spread of the different sources or how easy it is to do anything about them, but we can clearly see that the amount of plastic in the environment as the result of plastic bags and straws is very small indeed (0.01458 kg.pa vs 5.4 kg.pa).

It seems reasonable to say that reducing your plastic use in general would have a greater impact than just eliminating your plastic bag and straw use.

The ableism objection to banning plastic straws

Some have claimed that the ban on plastic straws is actually ableist, because some people rely on plastic straws to be able to drink. This makes sense, and I think the ban should perhaps be a little more nuanced to allow for this case (e.g. bars/restaurants can still give someone a straw if they need it for health/safety reasons). They could also use biodegradable or reusable straws, but not all of these are safe for the consumer (can pose a choking hazard, aren’t positionable, etc.).

However, one has to wonder – if someone is relying on a straw for safety reasons, why don’t they bring their own? Not all venues stocked plastic straws to begin with, so what did people who needed them do in those cases?

Conclusion

I think the ban on plastic straws and bags is ineffective. Not only that, I think it is a serious waste of time and money. One might retort with something like ‘it’s surely better than doing nothing’, but it gives people a false sense of achieving something and solving the problem. Of course, you could (and should) do all three of the above.

One surprising take away of this for me was that the plastic released to the environment from fishing was still a very small part of the plastic released to the ocean in general.

Some of my peers have started putting estimates on the time it takes to write posts like these, so I’ll start doing the same. This took me around 2 hours total to research and write.

* I’d like to share my disdain for pescatarianism here. It is potentially worse than doing nothing at all, but people think they are either reducing animal suffering or environmental damage.

Edit – It has been noted to me that the issue with straws is not just the volume of plastic, but the shape. It can pose a choking hazard more easily than some other plastics. Fair enough, but fishing nets also trap marine life pretty easily.