The resource efficiency hierarchy

The illustration left, shows, from top to bottom, 7 resource efficiency methods with decreasing cost-effectiveness and increasing environmental impact. (Click on the thumbnail for a more detailed version of this image).

Clearly the most desirable and value-creating approach is to remove the need for a resource, or to reduce or minimise use as far as practicable. The next method, to “re-source“, meets the remaining need with a material with a lowest ecological impact. We then get into how we handle waste. Reuse in the same process is better than recycling or “down-cycling” into a different process. If neither can be achieved, it may be possible to recover some part of the waste – for example converting embedded energy into heat by burning waste. The least desirable option is to reject or dispose of the waste into the environment.

Where disposal to the environment is the only alternative, then preferably the waste will be a nutrient for a biological process, such as compostable food packaging, or it will be inert. The worst case is where the waste has potential to cause harm, in which case it may need to be contained, treated or diluted to reduce the environmental damage.

The widths of the segments in the diagram above reflect the value the methods offer. Removing or reducing the resource saves their full costs, while reuse and recycling return some of the investment in the resource. End-of-pipe disposal usually comes at a net cost – not only is the intrinsic value in the resource discarded but there is often further cost for treatment or landfill.

This diagram uses the waste hierarchy, which has been around for decades in various forms. The difference is that I have added one method – “re-source”, which reflects the goal to reduce the impact on the environment from the resources that we use. In this extra method, once we have removed or minimised our need for a resource, we then consider alternative resources with a better ecological efficiency. For example if our resource is electricity, we should first start by employing every practical alternative to reduce its use and only then find out if we can source the electricity from an alternate supply with lower ecological impact, such as a renewable source. Using harvested rainwater water instead of treated water is another example of re-sourcing.

Some organisations behave as if the “re-source” choice is the only method they should use, so they will buy 100% renewable energy and declare “problem solved”. This approach can be much less cost effective for the organisation, as it does not lessen demand for the resource and because substitute sustainable sources are often more expensive.  Also, in a world where renewable supplies do not satisfy total demand, the extra resource that this organisation gets from renewable sources reduces that available to other organisations. Nevertheless this approach persists because it is seen as being lower effort than the alternatives, especially were the resources involved are a small part of the organisation’s input costs. There is more on this topic in my article about why certainty influences choices.

Multiple methods in the resource efficiency hierarchy tend to be applied in sequence, so the use of the resource is first minimised, then some material is recycled and the remaining waste disposed of. Unfortunately end-of-pipe solutions still dominate waste management in many organisations because waste is often seen as a “problem” that needs dealing with for consent reasons which leads to a tendency to use a technological “quick fix”. This is simply a matter of perspective: the visible waste output is seen as the problem rather than reducing the resource input. The resource efficiency hierarchy stresses dealing with the root causes of the waste, such as poor operations or poor product design, which causes the waste to arise in the first place as well as eliminating barriers to reuse, such as poor segregation of waste, rather than the end-of-pipe treatment.

It is sometimes helpful to look at organisational policies around waste to align these with the resource efficiency hierarchy. For example I worked with French cosmetics giant L’Oreal on some resource efficiency audits in the US and Europe and discovered that it was the policy that any non-product materials that left the site were categorised as waste. L’Oreal are to be applauded for using this strict definition of waste in their reporting to encourage the sites to eliminate all forms of waste.  However this definition had the unintended effect of making it preferable to burn waste in a biomass boiler on site as the emissions to air are not counted in waste reports. Prior to this definition, the waste from the shampoo lines was sold in bulk to nearby car wash companies who would use it to clean cars – thereby displacing their need for “virgin” detergents and no doubt leading to some very classy finishes on the local cars! This form of recycling is higher up the resource efficiency hierarchy but L’Oreal’s definition of waste unwittingly led to the lower recovery choice being favoured.

Although a bit clumsy these “7Rs” remind us that reducing demand is always a better strategy than improving the quality of supply (i.e. lowering environmental impact) of a resource. The best resource to use is no resource at all. Amory Lovins coined the term negawatt to describe this most valuable resource –  a watt of power saved.

 For more ideas and challenges check out all the posts on this site.

Learn what an effective resource efficiency framework looks like.

Read reviews of books on the theme of change.

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