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Climate change is not the only impact

There are various aspects of a company’s processes – in addition to its carbon footprint – which can have an environmental impact.

by Nicola Pichel-Juan

Image © vencavolrab |

Most lifecycle assessments (LCAs) within the footwear value chain are carried out as carbon footprint studies, which focus on the environmental impact of climate change expressed as ‘carbon dioxide equivalents’ (CO2e). As an example, a pair of shoes may be marketed with supporting information stating a carbon footprint or impact of 10 kg of CO2e per pair. This means that based on the boundaries set for the study, each pair of shoes has been calculated as being responsible for releasing 10 kg of greenhouse gases into the atmosphere.

Understanding and reducing the climate change impact of products and supply chains is vital to slowing and stopping any contribution to this problem. This is certainly relevant for the footwear industry, as well as being the impact that is most recognised and understood both within the industry and by the general public. However, depending on the types of materials being used and where in the world some of the supply chain activities are taking place, it may also be relevant to consider other environmental impacts.

It is crucial to understand how the environmental impacts are calculated and where the data comes from. In any LCA study, the first step is to define what is being studied (such as a pair of shoes) and what the boundaries of the study are. For instance, are the impacts being measured up to the point that finished goods are ready in a factory, or are the impacts of distributing, selling and even disposing of the product at the end of its life also to be considered?

At this stage, the impacts to be studied (an example being climate change) would generally be decided, although this can be revisited later in the study if it is felt that other impacts may also be relevant.

The next step is to collect all the primary data relating to the study. This will include information such as quantities of raw materials/components consumed, from where they are sourced, how they are transported to the first-tier production site, and energy/water consumption during the production process. Once the data has been collected and validated, the environmental impact(s) can be calculated. This is typically done using specialist software that will have access to environmental impact databases, which take the primary data and convert it into an environmental impact – for instance, climate change.

What is environmental impact data?

‘Environmental impact data’ comes from research studies previously carried out to measure the impacts of consuming certain items or undertaking certain activities. For example, an environmental impact database will hold data relating to the impacts of using a unit of electricity (kWh) in different parts of the world. It will hold data not only about the climate change impact of that electricity, but also for many other impacts, including those discussed in this article.

All this data from various sources is validated and collated together into an ‘environmental impact database’. Some of these databases are very broad and will hold a wide range of data, whereas some are very specific and may focus on particular industries, such as farming. When carrying out an LCA, this data is referred to as ‘secondary data’.

All environmental impacts that can be considered in an LCA study fall into one of the following categories: i) they cause damage to human health, ii) they cause damage to ecosystems, and iii) they lead to resource depletion.

What other impacts could be considered in LCA studies within the footwear industry?


‘Eutrophication’ is the over-enrichment of water with nutrients, particularly nitrogen and phosphorous. This in turn causes the growth of algae, which blocks sunlight from entering the water, killing any plants below the surface. When the algae die, they are decomposed by bacteria, which use up oxygen for respiration, ultimately causing fish and other organisms to die from a lack of oxygen.

One of the main causes for eutrophication is fertiliser run-off from farmland into water. Therefore, any materials in the footwear supply chain that can ultimately be traced back to farming and the potential use of fertilisers may have a link to eutrophication. There is a growing trend towards regenerative farming, which among other practices, aims to reduce or eliminate the need for fertilisers. A number of organisations within the footwear supply chain are working directly with farms to source so-called ‘regenerative materials’.


‘Acidification’ is caused by air emissions, predominantly sulphur dioxide and nitrogen oxides, which are released into the atmosphere through the burning of fossil fuels. The emissions increase the acidity of water, soils and clouds, the most common effect being acid rain. Therefore, electricity generated in countries with a greater dependence on the burning of fossil fuels will have a higher acidification impact than energy generated in areas focused on renewable energy generation through sources such as solar and wind power.

Water depletion and water footprint

While the actual production and assembly of finished footwear does not typically consume much water, considerable amounts of water can be consumed in some of the material manufacturing supply chains. Two key areas to consider are i) the growth of crops (for example, cotton) that are used to produce materials ultimately used in footwear, and ii) the dyeing and finishing of materials. This could be water consumed during leather tanning processes, or in the dyeing of polyesters and other materials.

The amount of water consumed will vary by region and according to growing practices for crops, as well as the technologies used in the production and finishing of materials. It will be more important to consider water consumption and depletion if an activity is taking place in a region or country that has issues with water scarcity. It is estimated that half a billion people around the world currently face severe water scarcity.

Land depletion, land use and land use change

Land depletion and land use may be relevant where farming of animals and/or cultivation of crops are occurring at some point in the supply chain. For instance, leather (despite being a by-product of the meat industry) has often been linked to deforestation in the Amazon, as trees are felled to provide more grazing pastures for raising cattle. As a result, considerable progress has been made in the leather industry on hide traceability.

Concerns have also been raised about an expansion of rubber plantations contributing to tropical deforestation and a subsequent loss of biodiversity. This highlights the importance of not generalising that one material type is ‘better’ or has a lower environmental impact than another material type, as the impacts will vary, according to each individual material, from where it is sourced, and the technologies used to produce it. In terms of natural materials, traceability back to the farm or plantation will be involved.

While many of the concepts discussed in this article may initially seem to be quite daunting or unrealistic to consider, the starting point for understanding the potential impacts is the same primary data that would be required for a carbon footprint analysis. This would include information relating to materials used in products, where the materials are from, how they are transported, where the final footwear production takes place and how much energy and water are consumed in the production process.

This primary data can then be used to generate a carbon footprint which measures climate change impact, or to measure other impacts using established and recognised methodologies. Once any particular ‘hot-spots’ or areas of potential concern have been identified, the organisation may then wish to carry out further investigation within its supply chain to establish, for example, if any practices have been introduced, or protocols followed in order to reduce any negative environmental impacts.

How can we help?

SATRA is able to carry out lifecycle assessments according to ISO 14040/44 for any organisation wanting to understand the impact of its products. Please contact for further information.

Publishing Data

This article was originally published on page 14 of the January 2024 issue of SATRA Bulletin.

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