When it comes to the environment, it can often feel like our individual voices are hard to hear in comparison to government and big business. Although this may be true in some cases, the public’s distaste for single-use plastic is being heard loud and clear. This past week, the B.C. government released the CleanBC Plastics Action Plan Survey which is asking for public engagement on a plastic waste reduction strategy.
But before we damn plastic to hell, let’s make sure we really know the facts. Although we know that plastic is a major issue, are we sure that the alternatives that we hail as the solution are really solutions? In other words, as we take this opportunity to have our opinions heard, let’s be conscious of our historic track record of creating unintentional consequences when we over-simplify a problem. Let’s explore this challenge through the example of bags: What is the environmental impact of plastic versus paper versus compostable plastic versus reusables?
The environmental implications of plastic bags are well known. Right from production, plastic bags harm our environment by being made from non- renewable, petroleum-based resources which contribute to climate change (1). At the end of a bag’s life, plastic bags often find their way into our environment despite being recyclable. Escaping recycling streams, many plastic bags slowly break up into microplastics causing both environmental and health implications that are not fully known (2).
From a contrary perspective, many consumers reuse plastic bags as garbage bin liners (3). A recent study presented by Metro Vancouver’s Solid Waste Services found that 64% of plastic grocery bags are reused to collect waste (4). Therefore, if the city were to ban plastic grocery bags, it is worth evaluating the environmental impact of consumers alternatively purchasing garbage bags, which would truly be “single-use”.
Paper bags are commonly deemed the sustainable alternative to plastic bags however various Life Cycle Analysis (LCA) suggest otherwise. LCA’s are a “way of calculating the inputs (materials, energy and water), outputs (wastes) and potential environmental impacts of a product or service throughout its life cycle” (5). Surprising to most, studies conducted in various countries have shown that paper bags have a bigger impact on the environment than plastic bags in every category except litter (6). These categories include fossil fuel use, water use, land use, chemical use, etc.
Although paper bags have large environmental footprints, they do break down much faster than plastic bags. In comparison to a plastic bag which takes anywhere between 400 to 1000 years to breakdown, paper bags take weeks (7).
The most common compostable bag is made from corn (8). While compostable plastic sounds like a favourable alternative to the traditional, petroleum-based plastic bags because they are made from a renewable resource, there are some concerning traits about them that are worthy of mention.
First, compostable bags are almost always made from GMO crops which generally means that the crops are not farmed in a sustainable way (9). Further, many composting facilities in Canada do not accept compostable plastic as they are hard to distinguish from traditional plastic bags and their rate of biodegradation is much slower than the facility’s processing time (10). This means compostable bags are often taken out at composting facilities sent to the landfill. You can read more about why compostable material in landfills is problematic, here.
Various LCAs find that reusable bags only have a better environmental impact than single-use plastic bags when they are reused more than 8-100 times (11). The range of reuse varies based on the materials used, where it’s made and how it’s made. These all impact the bag’s environmental footprint. A reusable bag made from recycled material significantly lowers the environmental footprint of a reusable bag (12).
One benefit of a reusable bag that cannot be found by all other materials previously discussed is that using one allows the consumer to break free of the destructive Take-Make-Dispose model of consumption, and instead support a Circular Economy. Read more about what this means here.
If you read this blog looking for a sure answer about which bag is best for the environment, I apologize, the answer isn’t here. As you can see from the studies mentioned in this blog, the best bag depends on what environmental variables are examined.
I will leave you with a bit of more general advice. There are two things that you can do that will never be harmful to the environment: (1) reduce your consumption and use what you already have. (2) Keep learning. The more research you do, the more you can be part of the solution to the world’s complex problems.
At SPUD, the sustainability team is continually looking for the best way to deliver groceries to our customers in a way that is environmentally friendly while keeping our food as fresh as possible.
(1) Lewis, Helen, Karli Verghese, and Leanne Fitzpatrick. “Evaluating the sustainability impacts of packaging: the plastic carry bag dilemma.” Packaging Technology and Science: An International Journal 23.3 (2010): 145-160.
(2) Xanthos, Dirk, and Tony R. Walker. “International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): a review.” Marine pollution bulletin 118.1-2 (2017): 17-26.
Environmental Defense. “Towards A Zero Plastic Waste Canada.” Environmental Defence. https://environmentaldefence.ca/plasticsdeclaration/
(3) Storrey, Karen. “Single-Use Item Reduction Workshop.” Metro Vancouver. 23 July 2019.
(5) Lewis, Helen, Karli Verghese, and Leanne Fitzpatrick. “Evaluating the sustainability impacts of packaging: the plastic carry bag dilemma.” Packaging Technology and Science: An International Journal 23.3 (2010): 145-160.
(7) Ritch, Elaine, Carol Brennan, and Calum MacLeod. “Plastic bag politics: modifying consumer behaviour for sustainable development.” International Journal of Consumer Studies 33.2 (2009): 168-174.
(8) Lewis, Helen, Karli Verghese, and Leanne Fitzpatrick. “Evaluating the sustainability impacts of packaging: the plastic carry bag dilemma.” Packaging Technology and Science: An International Journal 23.3 (2010): 145-160.
(9) Mooney, Brian P. “The second green revolution? Production of plant-based biodegradable plastics.” Biochemical Journal418.2 (2009): 219-232.
(10) Storrey, Karen. “Single-Use Item Reduction Workshop.” Metro Vancouver. 23 July 2019.
(11) Lewis, Helen, Karli Verghese, and Leanne Fitzpatrick. “Evaluating the sustainability impacts of packaging: the plastic carry bag dilemma.” Packaging Technology and Science: An International Journal
23.3 (2010): 145-160.
Greene, Joseph. “Life Cycle Assessment of Reusable and Single-use Plastic Bags in California.” CSU Chico Research Foundation (2011).