Measuring your carbon footprint should become, in the short or medium term, a common practice for businesses and other organizations (associations, local authorities) but also for individuals.

By carrying out its carbon assessment®, a company or an individual can identify and quantify the greenhouse gas (GHG) emissions generated by its activity, before deducing the actions to be implemented to control or even reduce its carbon impact. As a reminder, international commitments such as the Paris Agreement (COP 21 in 2015) aim to limit the extent of global warming, whose consequences — more frequent and more intense heat waves, rising sea and ocean levels, etc. — threaten the living conditions of human societies and other living beings on Earth [1].

While certain activities that emit GHGs are regularly mentioned in the media (energy consumption, transport), let's look at an emissions item that is less mentioned: purchases, and in particular purchases of tangible goods (physical products), which we distinguish from services (intangible benefits).

Carbon footprint of purchases, what are we talking about?

Definition and scope

First, let's clearly define the scope affected by the carbon footprint of purchases.

In the sense of the “carbon footprint®”, the reference method developed within ADEME in the early 2000s, calculating the carbon footprint of purchases by an organization (company, local authority, association, etc.) consists in measuring the GHG emissions generated by the manufacturing phase of the purchased products (or services) that will be consumed during the year. Examples include reams of paper for office printing or copper used in the production process of a metal pipe manufacturer.

The carbon footprint of purchases within the meaning of the Bilan Carbone® method is therefore limited to:

• The carbon footprint of the “upstream” phase, or manufacturing phase - we exclude the other phases of the product life cycle (distribution, use and end of life),
• The carbon footprint of the objects that will be consumed during the year - fixed assets are excluded (fixed assets bring lasting economic benefits to the company, beyond one year).

In addition, we can ask ourselves about the carbon footprint of waste from purchased goods (example: what happens to fabric scraps that are not used by a textile manufacturer?).

The stages of the manufacturing phase

By breaking down the manufacturing phase of a tangible asset, the regulatory methodology for calculating the GHG balance distinguishes the following steps :

• Extraction of raw materials,
• Energy consumption for the following intermediate steps:
• Processing of purchased materials/products assembly,
• For agricultural activities: land use change (examples: conversion of forests into cultivated land or built infrastructures — housing, industry, transport, etc.),
• Transport of products between all processing stages.

Manufacturing, one step among others in the product life cycle

Beyond the manufacturing stage detailed above, the total carbon footprint of a physical good is measured in terms of its life cycle, from the extraction of raw materials to the end of life.

There are generally 5 main stages in the life cycle of a product: the extraction of raw materials, manufacturing, distribution (transport to the customer/user), use and end of life.

Life cycle analysis consists precisely in evaluating all the different environmental impacts of a product or service (impact on the climate, impact on natural resources, impact on water, etc.).

The stages of the life cycle of a product.

Here is an example of the distribution of greenhouse gas emissions generated over the entire life cycle of a smartphone (iPhone 14 Pro), based on data provided by Apple. We note that production accounts for 80% of the carbon footprint of the product, compared to 15% for the use phase.

What is the weight of purchases in our carbon footprint?

Purchases represent a significant portion of greenhouse gas emissions for individuals and businesses alike.

The weight of purchases in the carbon footprint of individuals

In France, Carbone4, the leading consulting firm on energy and climate issues, has broken down the average carbon footprint of a French person and highlights the share linked to purchases: 1.6 tons of CO2e out of a total footprint of 9.9 tons CO2e, or 16% of the footprint that comes from purchases (household items, electronics, clothing, etc.). This figure (1.6 tons CO2e) does not cover purchases related to food or expenses related to public services (administration, education, culture, etc.).

The weight of purchases in the carbon footprint of businesses

With regard to companies, as shown by a study by the Carbone Disclosure Project (CDP) [3], scope 3 (which includes GHG emissions from the upstream/supplier and downstream/customers chain) can represent more than 90% of the carbon footprint of companies in certain sectors of activity (financial services, construction, transport).

Within scope 3, greenhouse gas emissions generated by purchases weigh on average 20% of the carbon footprint of businesses, but this figure can rise much higher for certain activities (44% for chemicals, 63% for agriculture, 63% for agriculture, 67% for the food, drink and tobacco sector).

Example of the chemical sector (breakdown of scope 3 GHG emissions).

How to control the carbon footprint of purchases?

Beyond measuring the carbon footprint of their purchases, businesses have various levers at their disposal to control or even reduce these GHG emissions.

Limit purchases : avoid or reduce purchases, when possible

Obviously, the first way to limit the carbon footprint of your purchases is simply to... reduce your purchases by avoiding superfluous orders. While this option may seem radical at first glance, it nevertheless has the merit of questioning purchasing decisions and ensuring that they are essential for the smooth running of operations. Each organization is then free to set the cursor at the level that suits it to differentiate what is essential from what is superfluous.

The key is to be aware that every purchase has a carbon footprint associated with it.

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Give priority to the purchase of lower-carbon products

Another option is to focus your purchases on goods whose production has emitted fewer greenhouse gases than other similar products. However, the absence of carbon data for some products hampers the integration of this decision criterion into the specifications of buyers. However, the general trend should lead to the promotion of the least carbon-intensive products in the years to come.

As shown in the table below detailing the carbon footprint of several smartphones, for example, we note that the storage capacity of an iPhone has a significant influence on the greenhouse gas emissions generated by its manufacture (by a simple double between 128 GB of storage and 1 TB).

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Criteria for analysing suppliers integrating the “carbon footprint” dimension.

Bet on refurbished

Another solution is to choose refurbished goods (“second hand”).

The logic is as follows: when we observe the carbon footprint of an object over its entire lifespan (Cradle-to-Grave, or “from cradle to grave”), a significant part of GHG emissions come from the manufacturing phase (extraction of raw materials, processing & assembly). Thus, by delaying the purchase of new products, we avoid the manufacture of these new products and therefore the greenhouse gas emissions generated by this manufacturing phase.

Minimize the impact of transporting your purchases

The product distribution phase, between the supplier and the customer, is also a lever to be studied to reduce the carbon footprint of the product measured over its entire life cycle.

The most obvious options are:

• the selection of a less carbon-intensive mode of transport: for the same distance covered, a delivery by sea (boat, often container ships) will have a lower carbon footprint than a delivery by plane. This option is subject to customer constraints. Indeed, although maritime freight emits fewer GHGs than airplanes for the same distance and the same weight transported, the delivery time is generally significantly longer by sea.

• the selection of a supplier that is closer geographically in order to reduce the distance travelled and therefore the GHG emissions of the transport service. However, this option is subject to the presence of suppliers meeting the needs of the customer in their region.

Extend the life of purchased goods (repair)

Beyond a possible — and sometimes difficult — reduction in purchases, you can reduce your carbon footprint by extending the life of the objects used, always with the idea of delaying the purchase of new equipment (same logic as for the purchase of refurbished equipment).

If we keep the example of smartphone, we note that by extending the duration of use of the terminal by 2 years instead of buying a new one, we avoid the emission of 16 kg CO2e (according to a study by ADEME)[4]). This extension of life is generally possible through the repair or reconditioning of existing objects.

Longer lifespan of smartphones and associated climate impact.

Valorize the product at the end of life

When a product is out of use, several options also make it possible to limit the carbon footprint of its end of life, such as recycling, reuse or energy recovery [5].

• Recycling refers to the direct reintroduction of waste into the production cycle from which it comes, in total or partial replacement of a new raw material (e.g. a bottle is melted and used to make a new bottle).
• Reuse consists in using waste for a purpose different from its first use, or in making, from waste, a product other than the one that gave birth to it (e.g. used car tires are used to protect the hull of a boat).
• Energy recovery involves the use of calories contained in waste, by burning it and recovering the energy thus produced to, for example, heat buildings or produce electricity.

Conclusion

Purchases of tangible goods are a significant source of greenhouse gas emissions, particularly related to the manufacturing stage, which consumes raw materials and energy to transform materials and assemble products.

Taking this carbon footprint into account in the strategy and Reporting Companies are gradually normalizing and becoming an issue of differentiation and competitiveness, within the framework of regulations that increasingly favour low-carbon products (obligations to display a repairability index or even a carbon score on products, etc.).

Carbon accounting is gaining ground and can no longer be ignored by decision-makers.