I really enjoy updates to previous news stories. Especially on economics based podcasts, articles and news outlets. Sometimes I feel like every day we collectively wake up, decide what new crisis the world is facing, what we should do to slow it down, and then go to sleep. Rinse, then repeat. No follow up, update, or reconciliation. And there are plenty of other concerns regarding present day media, and I’m not the first to complain about the 24 hour news cycle (which causes stress, and has shown to be biased and inaccurate).
But I was happy to see this week an update on previous environmental news, one that showed good news for a change.
Ozone levels are restoring to previous levels, and should be at pre 1980 levels by 2040, with holes closing around the arctic by 2045 and antarctic by 2066. It seems that the detection of CFC’s contributing to holes in the ozone in 70’s and 80’s, with follow through on the Montreal Protocol has actually made change and allowed the ozone layer to reform rather than continue to deteriorate. This is a huge win for scientists and humankind to slow down the effects of our inhabitance!
So, I think that following up on previous bits of content is important. And I'd like to do that with a paper I wrote in 2015 for a freshman level English class.
In this call to action, I talked about how using plastic bags at grocery stores have harmful affects on the environment, and that we should shift our demand towards reusable bags. Below is an excerpt from that paper:
By using this reusable grocery bag, you can conserve about 700 plastic bags over its lifetime. This bag, which can easily be kept in the car for your trip to the store, will eliminate waste produced by the numerous plastic bags we consume each year.
Plastic bags take hundreds of years to degrade, and break down by by photo-degradation, which is the process of light breaking it down into smaller and smaller fragments. These fragments easily soak up toxins that can contaminate our oceans and waterways. It is estimated that 1 million birds and 100,000 turtles and other sea creatures die each year due to the consumption of small pieces of plastic that they mistook for food.
Since that time of writing there has been a push here in the US towards reusable grocery bags (Philadelphia passed a ban on plastic bags in 2019 and many other cities and states have either bans or taxes on plastic). And through my own experience that word “can” seems to be doing a lot of work in the “700 plastic bags per reusable bag” statistic. I had a hard time finding the average life of a reusable bag but it seems that they live about 1-3 years which, if you grocery shop between once a day and once a week equates to 50-1000 plastic bags saved. So maybe it’s possible, since 700 is in that range, but realistically I’m skeptical. Then what does that 700 number even mean? At what point is using a reusable bag just as bad as plastic?
The “break even” on the amount of uses a reusable bag over the course of it’s lifetime (factoring in emissions, production and disposal costs on the environment) varies by study. It is estimated to be around 10-20 times for a polypropylene bag and 5 to 10 times for a polyethylene bag according to the UN environmental programme 2020. Another UK study found that a cotton bag needs to be used 131 times, a polyethylene bag 4 times, and a paper bag 3 times. And yet another Danish study found that cotton bags need to be used 7100 times, polypropylene bags 37 times, and paper bags 43 times.
So in general if I use a non-cotton bag for a whole year I should be good. But I’m sure I’m not the only one with a mountain or reusable bags in my apartment instead of just one or two.
Additionally, for the UK as a whole (which I do not have a personal experience with so not sure if now reusable bags are commonly sold at supermarkets) in 2019 sold 1.58 billion durable plastic bags which is equivalent to 57 per household, a 4.5% increase compared to 2018.
So what has happened to the plastic bag? And now why do we have so many reusable ones?
Supply
When I traveled to Scotland in 2016 I was amazed because the grocery stores I went to simply didn’t have any type of bag to collect your items, even if you wanted to buy one! So if you forgot to bring your bag, your alternative was to simply carry your groceries home in your arms. Comparing this to my experience with supermarkets in Houston (2019-21), Paris (2021) and Philly (2022-23) there was the ability to buy a reusable grocery bag at all locations, plastic bags available and commonly used in Houston, and paper bags available in Paris and Philly.
Could it be the case that because there was simply more supply, consumers didn’t make as much of an effort to remember their reusable bags and just bought them at the store or used paper?
Demand
It could be the case that reusable grocery bags have started to double for other uses. For example they might be used to not only transport groceries, but gym clothes, books, purses, picnic baskets, etc. that single use plastic bags previously weren’t used for. This would drive up demand for them relative to single use plastic bags, and wouldn’t be counted in the above UK statistic which assumes single used bags are simply replaced.
Additionally the size of the reusable bag might matter. For example one large bag might contain the same number of groceries as 20 single use plastic ones, but tear more often. So you might end up equating one bag to more than one single use one per trip.
Something else
It could also be the case that there is a broader cultural trend associated with reusable bags. Instead of a lifeless, mundane plastic bag carried around, a reusable bag with a print might serve as a fashion piece. A statement on your trendiness and character as seen in the example below.
So on different occasions you might demand a different bag. One to even match your outfit. Hence the need to buy more bags, and continually update them with your wardrobe.
Or instead of a fashion trend it could be that the main environmental concern has nothing to do with emissions or life cycle analyses, but rather trying to avoid plastic entering waterways. So even if people don’t end up using reusable bags to the extent of their life cycle from an energy standpoint, it might be worth the cost to protect wildlife. This theory may make sense since many cities and beach towns have implemented the ban on plastic bags. On this front, I’m not sure how to compare loss of wildlife to emissions to determine an overall affect on the environment, but maybe someone in the comments might know if there is a metric for this.
Or it could be the case that supermarkets just got good at adjusting to the new regulation. That a new market was created to sell products and end up buying more bags even though the intended policy through bans and taxes were to promote less bags. And there is just a lag for companies to adjust and create these products from the time that bans started popping up.
Conclusion
In summary, this example seems to show a few things. Number 1 being that setting regulation is hard. And even though you think you might know the outcomes and intentions of a policy there might be unexpected consequences, which may even go against your intentions for the policy. People and companies generally seem to be good at reacting to regulation in their best interest (even if people are irrational!) And number 2 is that conducting life cycle assessments are very hard, and you can get vastly different results based on the set of assumptions you use.
In 2015 I was very passionate about using a reusable bag, and in fact even now I’ll opt to carry my groceries if I can rather than use a single bag. But in 2023 I’m less idealistic, and have a greater appreciation at how difficult cooperation is en masse. But if the cause is important enough, like closing the ozone hole or stopping global warming, I know we must work towards it.