How to allocate environmental impacts between sheep products?

Allocation Methods explained

In our earlier blog post, we wrote a brief introduction to the importance of wool Life Cycle Assessment. In this edition, we will look in more detail at one important aspect of LCA, the so-called allocation methods.

In LCA all environmental impacts are accounted for. In the case of wool, LCA also accounts for the impacts of sheep such as their water consumption, land use, CO2 or methane emissions released through their digestive system, etc. As sheep are multi-purpose animals they produce not only wool but also meat, milk, lanolin and other by-products. Therefore these emissions need to be distributed to the different products sheep produce. To put it in different words, it would not be fair if your wool t-shirt took on all the environmental impacts while the lamb chops you might order tonight for dinner get a free pass.

How to divide impacts?

This raises the question about how these impacts should best be allocated to the different sheep products. The International Standards Organisation (ISO) defines different allocation methods and also ranks them as to which methods to prefer when conducting LCA. The least preferred but often the easiest method, for example, is economic allocation. Using this method means that the environmental impacts are divided in relation to the price of the different sheep products. For wool, this method is also the least preferred, as sheepmeat and wool prices vary from week to week and in addition wool prices for fine wool versus coarse wool also have a huge variation. So which price should be used?

Biophysical allocation most suitable for sheep products

Because it is such an important topic, a team of internationally well known LCA researchers have studied which allocation is the best way to calculate the environmental impacts of sheep across their different products. The result is biophysical allocation. This allocation method looks at how much protein is required to produce one pound of wool vs. one pound of meat for example.

Better understanding environmental claims

Truth be told, this is quite a technical little detail and you may wonder how this has anything to do with you? Well, if you are interested in living a sustainable lifestyle you rely on information provided to you about the environmental impact of a product. Every day claims are being made about how a certain product is more sustainable over another and the next day you may hear the exact opposite claim being made. This is due to the fact that scientific research on environmental impacts is a relatively new field and there are constantly new facts being discovered. Allocation methods are one of these research fields. As you learned in this blog post, there are different ways of measuring environmental impacts which lead to different results. Knowing this makes you a more savvy individual who can question environmental claims and help you make true sustainable choices.

If you are interested in reading more about allocation methods have a look at these links here.

If you have any questions or comments, let us know in the comments section below. We look forward to hearing from you. In our next blog post, we will talk about environmental benchmarking tools.

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