Consumers and suppliers alike are seeking to understand the environmental impact of products to make better informed purchasing decisions. For the sustainability of a product to be understood, the first step is understanding the methods of measurement and interpreting them correctly.
One popular concept is ‘product circularity,’ which is increasingly being used in assessing the environmental performance of products.
But where does the concept of product circularity sit next to other sustainability metrics, and how can we generate the most meaningful understanding for how to optimise product sustainability from it?
Let’s start with the basics.
What is a life cycle assessment?
A life cycle assessment (LCA) is a traditional method to measure the environmental performance of a product by capturing its life cycle and quantifying its impacts on the climate, ecological systems and resource consumption. All of the material and energy input and output flows of the product, the lifetime of its use phase and even it’s potential number of re-uses may be captured.
What is product circularity?
Product circularity describes an application of “circular economy” principles specifically for product materials. A circular economy is an economic system which deviates from the traditional linear “take-make-dispose” economy. It aims to reduce the consumption of finite resources, designs out waste generation and maximises the lifetime of products.
The Ellen MacArthur Foundation and Granta Design developed material circularity indicators (MCI) to measure product circularity. This methodology considers multiple aspects of a product including but not limited to the inputs of virgin vs. secondary material, number of use cycles, product lifetime and recycling rate at end of life.
Circularity is highly compatible with other sustainability methodologies like life cycle assessment, generally requiring similar information to complete a reliable assessment. However, rather than quantifying the impact of the product based on environmental metrics, the product is assessed on an economic scale. This scale has no bearing on the environmental impact of the product.
Product circularity vs. product efficiency
Neither assessment provides a complete picture for sustainability, which should really consider environmental, economic and social sustainability.
The importance of understanding this distinction is that a product might be very circular, without actually having a good environmental performance. This means that an environmental claim about a product should not be based solely on its circularity score. If this difference is not clearly communicated, the sustainability story of a product could be completely misunderstood and misinterpreted, with detriment to the sustainable success of the product and owning company!
Circular but impactful, or linear but ineffectual?
For many products, shifting away from virgin materials, harnessing more recycled materials, increasing the product lifetime and recycling at end of life, improves both the circularity and the environmental performance.
For example, a beverage carton made of renewable-sourced cardboard will also yield by-products that are used as thermal energy to fuel the manufacturing process, so they are relatively independent from virgin, fossil-based resources. They are moderately circular, and also low impact.
Similarly, a glass bottle that is reused 30 times will be considered highly circular, and its environmental impacts will be spread out across 30 life cycles, meaning its environmental burdens in one life cycle may be low.
But circular does not always mean sustainable. One example is a plastic bottle.
A plastic bottle may accrue a mediocre MCI score because it is derived from virgin fossil-based materials, it is generally single-use, and the recycling rate in Europe was only 42% in 2019. By comparison, even a single-use glass bottle will achieve a very high MCI score for its recycled content and higher recycling rate e.g. 66% in Europe in 2019.
However, the manufacturing of the glass bottle is very energy-intensive, and requires more material than a plastic bottle. The lightweight nature of the plastic bottle compared to the bottle means it is incredibly product efficient, as a minimal mass of material is required to provide the product. This gives a favourable packaging-to-product ratio.
When compared side-by-side, the plastic bottle has a better environmental performance than the glass bottle, despite the MCI scores.
Putting your products in context
Both LCA and circularity assessments are based on assumptions which are heavily dependent on the state of the material markets. In an assessment, we may assume that a glass bottle will be reused 10 times.
However, how likely is it that a glass bottle will actually be reused 10 times?
After all, how often do you see discarded beer bottles on the side of the road? Likewise, plastic products might be considered highly recyclable, but how healthy is the market demand for that material? Is it over-saturated or under-saturated?
In our previous article “Recycling isn’t the answer,” we addressed the fact that recycling is a commodity business and follows annual value trends very similar to those of agriculture, metals and oil. This means that if oil prices fall below the price of recycled plastic material, there is absolutely no incentive for a manufacturer to purchase more expensive recycled material which may be of a lower quality.
How achievable is the recycling rate you are quoting?
What does this mean for sustainability in practice?
Material circularity assessments are an invaluable tool to measure product sustainability in tandem with life cycle assessments and other tools for measuring sustainability. In fact, it is fundamental to strive to find and understand multiple perspectives on the sustainability of your product, and to capture the leading environmental, social and economic influences on your product wherever possible.
What is important to remember is the context of a product – the markets it operates in, the actual use by consumers, and the regional markets at the end of life are crucial to have an accurate understanding of your product in practice.
Sustainability is continuously evolving, and should not be blinkered by one method or another – circular economy is one highly innovative theory which has captured public attention, drives change, and certainly won’t be the last in our lifetime.