Product Carbon Footprint (PCF), Explained

Step-by-step guide to how product carbon footprints are calculated, and why you and your stakeholders need them.

What is a product carbon footprint?

A product carbon footprint (or PCF) is the calculation of all of the greenhouse gas (GHG) emissions generated in the supply chain of a specific product. It is usually expressed as a carbon intensity.

For example:

• A car in a showroom might have its carbon intensity expressed as 40 tonnes of carbon dioxide equivalent (tCO2e) per vehicle.
• A consignment of aluminum might have its carbon intensity expressed as 18 tCO2e per tonne of aluminum. The total emissions of that consignment might also be reported.

Product carbon footprinting is also referred to as ‘product life cycle accounting’, ‘product life cycle assessment’ (LCA) or ‘product life cycle emissions inventories’. However, LCAs commonly cover a broader range of environmental impacts than just GHG emissions.

What do we mean by a ‘product’s supply chain’?

A product’s supply chain includes upstream activities (e.g. mining, transport and processing of materials that go into your company’s production processes) and downstream activities (e.g. delivery to customer and use and disposal of goods). However, not all PCF calculations include emissions from the downstream supply chain. These calculations are called partial lifecycle inventories (see guidance on boundaries below).

How are product carbon footprints (PCFs) calculated?

There are four overarching steps to calculating a PCF.

Step 1: Define the question

As emphasized in the seminal ‘Hitch Hiker’s Guide to LCA’ by Henrikke Baumann and Anne-Marie Tillman, the answer depends on the question.

This means being very clear on the goals and scopes of developing your PCF before selecting an approach. What you’re trying to achieve will impact how deeply you go into certain elements of the product life cycle, and your method of calculation.

Examples of the questions you (or your stakeholders) might be asking include:

• Roughly what is my product’s carbon footprint?
• Is my product lower or higher carbon than this other product?
• Where are the biggest hotspots in my product’s supply chain?
• Does my product meet my customer’s low-carbon threshold?

Step 2: Set the system boundary

The system boundary, or the product boundary, for the PCF can be either cradle-to-grave or cradle-to-gate. This will depend on the type of product you are selling:

• An intermediate product, where the final use of that product is unknown, will normally be evaluated cradle-to-gate (for example, an aluminum ingot);
• A final product should be evaluated cradle-to-grave (for example, diesel sold for use in a vehicle or a component built for batteries)

1. Cradle (extraction of raw materials) to grave (the whole lifecycle).

A cradle-to-grave PCF includes all the GHG emissions associated with the production of the product, from the extraction of raw materials to end-of-life, covering the product’s upstream and downstream supply chain.

Step 3: Collect the data

There are two kinds of data that a company needs to collect in order to calculate a product carbon footprint:

1. Information about the production processes (within the boundaries set out)
2. Emissions data (usually emissions factors)

The Greenhouse Gas Protocol (GHG Protocol) Product Life Cycle Accounting and Reporting Standard allows companies to make choices about the quality of the data they collect.

Step 4: Calculate the emissions

To calculate the PCF, use the formula activity * emissions factor for every activity, to develop the product’s emissions inventory. If your production process also involves co-products or by-products, the GHG Protocol sets out methods to ensure your emissions calculations relate only to the product under analysis.

How are product carbon footprints used?

Reporting emissions with product carbon footprints

A key use case of product carbon footprints is fulfilling customers requests. Manufacturers use CarbonChain to provide Product Carbon Footprints (PCF) that customers can trust, at the point of purchase or delivery, expressed as total emissions or emissions intensity.

Reducing emissions with PCFs

For many companies, developing a PCF is not only about compliance and fulfilling requests; it’s about measuring emissions in order to set and achieve targets to reduce them in line with global climate goals.

Why are product carbon footprints important?

PCFs are critical metrics in the transition to a net-zero economy, especially in high-emitting and hard-to-decarbonize sectors which may have large emissions variations depending on production processes. With a PCF, manufacturers and commodity traders can:

Inform decarbonization efforts

A tonne of aluminium can range between 3-20 tonnes of carbon dioxide equivalent in carbon intensity. PCFs reveal the highest and lowest emitting products, and the biggest carbon hotspots within a product’s supply chain.

Inform market decision makers

PCFs enable buyers and trade finance providers to compare product emissions within product lines or from different suppliers, so they can make informed purchasing, financing and offsetting decisions.