Although Tim Minchin’s Canvas Bags (view video at bottom of article) might be considered a little too wacky, it does make a darn good point. Employing reusable bags is an exceptionally simple way to, significantly, reduce one’s ecological footprint, without having to spend much effort or money in the task. However, the usage thereof is quite a controversial topic for studies have suggested that, in some cases, reusable bags actually harm the environment more than their single-use counterparts. But fear not! The cause of that problem lies not in the nature of the bags themselves, but in the way consumers make use of them. All it takes to avoid making mistakes in this field is a small dose of awareness.
In 2009 (later reviewed and edited in 2010) the Environment Agency, a public body that serves England and Wales, published Life cycle assessment of supermarket carrier bags: a review of the bags available in 2006, a report in which it assessed and compared the environmental impacts of several types of shopping bags, including single-use and reusable ones. The study encompassed – only – bags available at supermarkets, most notably:
- the High-density polyethylene (HDPE) bags, very lightweight, made of thin and frail plastic, tank-top-shaped, offered in almost all supermarkets and conventionally single-use;
- the Low-density polyethylene (LDPE) bags, lightweight, made of thicker and more elastic plastic, offered in almost all supermarkets, conventionally reused;
- the Polypropylene (PP) bag, large and made of thick durable plastic, offered in most supermarkets, comes with an insert to stabilise the base, intended to be reused many times;
- paper bags, offered in few stores, reusable;
- cotton bags, offered in few stores, intended to be used many times.
If you are unsure of what the above look like, although they are surely present in your daily life, you can use image search or visit page 13 of the report:
http://publications.environment-agency.gov.uk. There are, of course, many more types of bags like canvas, hemp and jute bags, but they were not included in this study.
Having investigated the Carbon Dioxide Equivalent (CO2e) emissions of each bag at the stages of: extraction of raw materials, production processes, transport, end-of-life, and recycling, the report deduced the following. To take a reusable bag below the global warming potential (measure in kilograms of CO2e) of a HPDE bag, it needs to be used numerous times. A paper bag must be used at least 3 times, an LDPE bag at least 4, a PP bag at least 11 and a cotton bag at least 131. Naturally, making thicker and more durable bags requires more intensive – and thus more polluting – processes than making thin, single-use ones. The key to making the reusable more environmentally-friendly lies in the number of times they are used, so use and reuse and reuse! Many environmentally-conscious consumers have failed to take this notion into consideration, and have therefore unintentionally hurt the environment. Let us try to prevent this from happening again.
What concerns other types of bags, the same notion applies. Thus when seeking to purchase a reusable bag – for environmental reasons –, one must ensure s/he gets well-informed. In addition, it is likely that in the future more articles on non-plastic reusable bags will appear, so keep your eyes open…
To view Tim Minchin’s video on the use of canvas bags click here