We know that the use of products is polluting, and that the materials used to make them require resources. But we think, often mistakenly, that this “ecological weight” is proportional to the weight of the product, whereas in fact, it’s often far greater. The concept of the ecological rucksack was developed to help make us aware of it and to keep the planet cleaner. Here are our explanations.
Calculating the ecological footprint
The ecological footprint estimates the proportion of resources needed to produce and use a product or service. It’s a useful tool for measuring the pressure exerted by mankind on nature and resources, and makes it possible to quantify that impact. This footprint is translated into a date by which the resources available over a period of one year are expected to be used up, or into a number of used-up planet symbols, or even nothing more than figures, all of which represent the alarm bells that often circulate on social media. So what’s the problem? Well, this calculation only takes into account the ecological impact of using the product, especially its impact on the climate, and not everything that was needed upstream… Or downstream. Whereas this is where a big proportion of the ecological footprint lies: in manufacturing processes, freight transport, development resources and waste disposal. This “dark side” of our ecological footprint is said to account for some 3/4 of the total impact of the product’s life cycle.
The submerged part of the iceberg
When we talk about the ecological rucksack, we often depict it as an iceberg. This is because, in our view, the product carries “visible” weight as an object, and also invisible weight: the sum of the resources used. These are resources that the consumer can’t identify, since they pertain to the design and manufacturing of the product, its impact on biodiversity and on pollution (of the air, water and soil). Not forgetting the energy resources required to manufacture the product! These are abstract notions that are difficult to pin down.
However, they are inherent in every product, as though these resources used were attached to it in a cloud or balloon floating above it… Or like an invisible weight that each product carries, hidden on its back: it’s the idea of the ecological rucksack invented by German researcher Friedrich Schmidt-Bleek.
The concept of the “ecological rucksack”
This concept measures the weight of the natural resources needed to manufacture the finished product, in tons of resources per ton of products. So the calculation goes beyond the grey energy concept, which only takes into account the energy used to manufacture a product or develop a service.
The ecological rucksack registers “Material Input Per Service unit” (MIPS), across five categories of natural resources. This virtual rucksack can be 30 times heavier than the product wearing it, and sometimes far more than that. For example, in the electronic devices category, a smartphone requires 70 kg of resources, i.e. some 600 times its own weight!
How is this ecological rucksack weight calculated?
The ecological rucksack weight estimates the amount of resources needed for the product to fulfil its function:
- Non-renewable resources: mineral (minerals, sand), fossil (oil, gas, coal) and natural (earth,, soil)
- Renewable resources: from biomass (picking, gathering, hunting), farming, woodland (timber).
- Soil displacement: farming and forestry (ploughing, erosion, digging mines).
- Usage of water that has been diverted from its natural course (surface water or that from water tables).
- Usage of air to effect chemical or physical changes.
This is very difficult to calculate, since traceability is not always applicable here. Also, the consumer has little chance of being able to do so, since the data is provided by companies, some of which try to mask the amount of water and energy they use just to produce a T-shirt or steak.
Ecological rucksack and eco-design
This notion and calculation are two important tools for companies wishing to develop the use of new materials and production processes that are cleaner and require less energy, and for brands that wish to switch to eco-design for their products. These tools are also important in terms of guiding our behaviour as consumers (even without having any figures to hand), being aware of the resources that lie behind each product, and thinking about the product’s actual usefulness versus its ecological footprint.
You’ll often see depictions of a character walking along with a cloud of logos attached to it or to its smartphone, illustrating the notion of the “cloud” or of social media. Maybe this is how you’ll view products on store shelves from now on. Be aware that there is an alternative: purchasing second-hand goods, which gets maximum use out of the ecological rucksack. There are also transparent, local brands that use clean processes and have a smaller hidden footprint.