If you’re anything like me, you let out a sigh of relief when you see bags made of paper, not plastic, in the store you happen to find yourself in with your a-hundred-times-reused cotton tote. When buying tomato purée, you opt for the glass jar to reuse in your favourite zero waste store, rather than the discardable can. But are jars really more sustainable than cans? Surely, at least paper bags are better than plastic ones? Let’s take a look at the facts.
How is the sustainability of packaging determined?
Although some packaging options might seem instinctively greener to us, their true sustainability comes down to several factors. Using a technique called life cycle assessment, the environmental impact of the raw resources, production process, transportation and (secondary) packaging, usage, and disposal is assessed. [1, 2] The packaging’s durability and weight are also important in assessing its impact on the planet, which, in addition to the greenhouse gases released during its lifetime, includes the consumption of water and energy, the toxic substances released, and the impact on air quality, among other factors. [2]
The stages of life cycle assessment. Image source: [1]
Are paper bags really better?
A study conducted by the Environment Agency (EA) examined the sustainability of carrier bags in the UK, and found that paper bags need to be reused at least three times to have a lower environmental impact than conventional single-use plastic bags. [3]
Another report by the Northern Ireland Assembly suggests that four times more energy is required to produce a paper bag. [2] In both cases, the resource use and manufacture stages have the largest impact on the environment. [3] Trees must be cut down to produce paper bags, and in addition to releasing greenhouse gases, the production process requires the use of toxic chemicals, creating substantially more pollutants than the manufacture of plastic bags, the report adds. [2]
Non-plastic bags are often not as low-impact as we think they are. Image source: [4]
Meanwhile, plastic bags are made from waste products of natural gas or oil. Although their manufacture releases a large amount of carbon and toxic substances, they are more lightweight and durable than paper bags. [2] This means the transportation of paper bags will require more energy, and they will be more likely to tear, decreasing the possibility of reusing them many times. [5]
While decomposition and the recycling process are further problem areas for both plastic and paper, paper bags are much less likely to be a cause of litter and thus endanger wildlife. [2, 5]
Cotton bags seem to have the reputation of being the most environmentally friendly. However, the EA established they need to be reused 131 times before being more sustainable than conventional plastic bags, mainly due to the energy required in cotton production. [5] Still, if they are reused several hundred times, they appear to be the most sustainable option. [2]
What about glass vs. aluminium?
When comparing aluminium and glass containers, it is important to note that both materials can be recycled almost indefinitely. [6, 7] The recycling of aluminium cans requires about 90% less energy than that of glass bottles, but the raw aluminium manufacturing process is much more energy intensive. [8] It needs to be extracted by electrolysis from its ore, bauxite, the mining of which leaves behind wastelands and pollution. [7, 9] Meanwhile, the impact of the glass production process mainly comes from heating sand, limestone, and other materials in a furnace. [6]
While a brand-new can is responsible for almost two times the greenhouse gas emissions of a new bottle [10], it is more lightweight and requires less energy for transportation. [11] Experts’ opinions vary, but it appears that aluminium is less sustainable than glass when virgin, and more eco-friendly once recycled. [8]
Reuse, and reuse again
All in all, while all packaging choices come with their downsides, there are many ways in which we can reduce their environmental impact once they are produced. Here are a few suggestions:
Be mindful of the origin and different life cycle stages of a product before buying it. Focus not only on the packaging, but the product itself: for example, beef has a substantially larger impact on the environment that the same amount of tofu. [12]
Try to reduce the amount of packaged foods you buy, and repurpose the containers already bought. You can reuse glass jars to buy loose foods in your local zero waste store, or get creative by converting cans into pen holders.
Remember to bring your own bag when shopping, and don’t accept any type of carrier bag unless necessary. If you do, make sure to reuse it as many times as possible. Reusing plastic grocery bags as bin liners is also beneficial to reduce their global warming potential, the EA suggests. [3]
Keep in mind that the most sustainable option is upcycling the things you already own, rather than buying new tote bags and fancy mason jars to fit in with the mainstream zero-waste movement. Why not try turning an old T-shirt into a new tote bag by following this simple, no-sew tutorial? [13]
Last but not least, in addition to changing our individual habits, it is vital that we hold the companies producing enormous amounts of packaging accountable. The 2nd episode of The Yikes Podcast is a great way to find out more about pushing for system change. [14]
Make sure to check out the rest of our articles about plastic and recycling, and follow us on Instagram for all things sustainability.
Resources and further reading
[1] TED. (2013). Paper beats plastic? How to rethink environmental folklore [Video]. Retrieved 15 July 2020, from https://www.ted.com/talks/leyla_acaroglu_paper_beats_plastic_how_to_rethink_environmental_folklore.
[2] Bell, K., & Cave, S. (2011). Comparison of Environmental Impact of Plastic, Paper and Cloth Bags [Ebook]. Northern Ireland Assembly. Retrieved 15 July 2020, from http://www.niassembly.gov.uk/globalassets/documents/raise/publications/2011/environment/3611.pdf.
[3] Edwards, C., & Meyhoff Fry, J. (2011). Life cycle assessment of supermarket carrier bags: a review of the bags available in 2006 [Ebook]. Environment Agency. Retrieved 15 July 2020, from https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/291023/scho0711buan-e-e.pdf.
[4] [Image]. Retrieved 29 September 2020, Media from Wix.
[5] Edgington, T. (2019). Plastic or paper: Which bag is greener?. BBC News. Retrieved 15 July 2020, from https://www.bbc.com/news/business-47027792.
[6] The Glass Packaging Institute. (2010). Complete Life Cycle Assessment of North American Container Glass [Ebook]. Retrieved 15 July 2020, from https://www.adhesives.org/docs/pdfs/n-american_glass_container_lca.pdf?sfvrsn=de4efa28_0.
[7] Knight, L., & Bowler, T. (2013). Aluminium: The metal that just keeps on giving. BBC News. Retrieved 15 July 2020, from https://www.bbc.com/news/magazine-25020651.
[8] Graham, R. (2019). Glass bottles vs aluminium cans: which are better for the environment? | Living. Euronews. Retrieved 15 July 2020, from https://www.euronews.com/living/2019/07/17/glass-bottles-vs-aluminium-cans-which-are-better-for-the-environment.
[9] Bauxite in Malaysia: The environmental cost of mining. BBC News. (2016). Retrieved 15 July 2020, from https://www.bbc.com/news/world-asia-35340528.
[10] Nag, R. (2016). Life Cycle Assessment on Aluminium Can and Glass Bottle for Packaging of 500 ml Beer [Ebook]. Retrieved 15 July 2020, from https://figshare.com/articles/LIFE_CYCLE_ASSESSMENT_ON_ALUMINIUM_CAN_AND_GLASS_BOTTLE_FOR_PACKAGING_OF_500_ml_BEER/3206518.
[11] Profita, C. (2013). The greener beer: In bottles or cans?. OPB. Retrieved 15 July 2020, from https://www.opb.org/news/blog/ecotrope/the-greener-beer-bottles-v-cans/.
[12] Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360(6392), 987-992. https://doi.org/10.1126/science.aaq0216
[13] No Sew T-Shirt Tote Bag. Instructables. Retrieved 29 September 2020, from https://www.instructables.com/id/no-sew-t-shirt-tote-bag-1/.
[14] Loach, M., & Becker, J. (2020). EPISODE 2: Can lifestyle change save the planet?. The YIKES Podcast [Podcast]. Retrieved 29 September 2020, from https://podcasts.apple.com/gb/podcast/episode-2-can-lifestyle-change-save-the-planet/id1498623503?i=1000466947790.
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