Carbon data: where to find the right emission factors for your scope 3
Any company wishing to make a commitment to sustainable development will need to carry out a greenhouse gas (GHG) assessment. In doing so, it will note the importance of GHG emissions from its scope 3 - i.e. all its indirect emissions: purchasing, transport, product life cycle - and a key question will arise: where to find the right carbon data for these items? And above all, how do you choose the emission factors that truly reflect the reality of your activities and those of your partners and suppliers?
Behind every tonne of CO₂e lies a strategic piece of data: the emission factor. This small coefficient translates kilometers traveled, kWh consumed, tons of material or euros spent into greenhouse gas emissions. Choosing the most relevant and up-to-date factor guarantees an accurate GHG balance sheet - and lays the foundations for a robust climate strategy.
Conversely, the wrong factor can distort results, confuse priorities and compromise reduction efforts. The key is to know where to look... and how to judge the reliability of sources.
Contents
Understanding the key role of GHG emission factors
Defining an emission factor: the basic unit of carbon calculation
An emission factor is a reference value that converts activity data - such as liters of fuel consumed, kWh of electricity used or tons of materials purchased - into the quantity of greenhouse gases emitted, usually expressed in kilograms or tons of CO₂e.
This coefficient is the basic unit of carbon calculation. It links the physical world to the emissions it generates. There are thousands of emission factors, defined by reference organizations such as ADEME, the IPCC, or international databases such as EcoInvent. These factors vary according to the sector of activity, the type of energy or the technology used.
Choosing an up-to-date factor adapted to the company's context is therefore essential to guarantee the robustness, comparability and credibility of a carbon balance sheet or report.
When indirect emissions change the game
When an organization begins to measure its indirect emissions, it enters a complex field, namely that of scope 3. This scope includes all emissions that are neither directly generated by the company (scope 1), nor linked to the purchase of electricity or heat (scope 2), but which come from its value chain in the broadest sense: purchases of goods and services, business travel, waste management, investments, etc.
It is often in these indirect emissions that the majority of a company's carbon footprint is concentrated. Yet it is also the area where data is most scattered, and hardest to collect and make reliable.
Under these conditions, the choice of emission factors becomes a critical lever. Organizations often have to deal with approximate or incomplete data. The use of generic factors is commonplace - but it entails major risks: poor estimation of emissions, false priorities for reduction, and errors in deciding which actions to take.
A single poorly selected emission factor can be enough to distort the assessment of an entire category, and by extension the company's overall carbon footprint.
Conversely, using a factor that is documented, precise and aligned with operational specifics - the nature of activities, processes used or location of flows - provides reliable results that can be directly used to steer a relevant decarbonization strategy.
With this in mind, the GCI platform integrates an automatically updated database, based on the best available sources: Base Carbone®, ADEME, EcoInvent, etc. The user is thus guided towards the most relevant factor, without having to choose between hundreds of technical references. The user is thus guided towards the most relevant factor, without having to arbitrate alone among hundreds of technical references.
Towards greater precision: integrating supplier data (PCF, FEMPP®...)
While generic emission factors can be used to estimate emissions initially, they quickly reach their limits when it comes to refining the carbon footprint of a specific product, service or purchasing item. To go even further, some organizations choose to integrate more precise upstream data, directly from their suppliers.
This is the case, for example, of :
- PCF (Product Carbon Footprint): a detailed analysis of the emissions generated over the entire life cycle of a product, provided by the manufacturer.
- FEMPP® (Personal Precise Monetary Emission Factors): emission values calculated by suppliers on the basis of actual data from their own activities.
The integration of these specific data enables :
- more detailed and realistic modeling of purchasing items,
- better alignment with CSRD, SBTi or key account customer requirements,
- and, above all, to prioritize reduction actions where the impact can really be measured.
This data reinforces the credibility of the carbon footprint, by creating a direct link between the actual emitter (the supplier) and the client (the company).
It is precisely to meet this need that the GCI platform offers Decarbo'Supply®: a tool designed to involve suppliers in the carbon approach, enabling them to transmit their own emission factors (PCF, FEMPP®, LCA...) and thus significantly improve the quality of indirect data.
In this way, companies can move from a default approach to a collaborative, progressive and controllable logic.
How to sustain and strengthen your business through a successful low-carbon trajectory.
Where can I find reliable emission factors?
Public bases: a solid foundation
ADEME's Base Carbone® is the reference in France: free, open and regularly updated. It contains thousands of emission factors for energy, transport, purchasing, waste, etc.
Internationally, we can also draw on :
- Defra (UK), very precise on freight and energy,
- EPA (United States), adapted to the North American context.
Advantages: transparency, reliability, regulatory consistency.
Limitations: data sometimes too general or far removed from operational reality.
Private and sectoral databases: for further information
Some databases offer more detailed LCA data:
- EcoInvent, one of the most comprehensive LCA databases (fee-based access),
- GHG Protocol tools, particularly used internationally.
Other sources are sector-specific:
- TK'Blue for transport and logistics,
- Professional organization databases (agri-food, textiles, chemicals, etc.).
Benefits: more accurate estimates, suitable for complex processes.
Customized data: the key to precision
For certain items(strategic purchasing, transport, production), internal or supplier data are essential:
- PCF transmitted by suppliers (via Decarbo'Supply®),
- FEMPP®, or GHG emission factors calculated from their own GHG balance sheets,
- Internal data (fleet, process, actual consumption, etc.).
This cross-referencing of generic and specific data enables us to produce a GES balance sheet that reflects the company's reality.
On the GCI platform, all the major reference databases (Base Carbone®, Ecoinvent, Defra, EPA...) are accessible. Above all, companies can involve their suppliers with the Decarbo'Supply® solution. Thanks to a dedicated, free portal, suppliers can calculate the carbon weight of their products or services and transmit their data directly to their customers.
How to select the right emission factors for your company?
Adapt it to your sector
Each sector has its own specificities. Using an emission factor that is too generic means running the risk of missing out on your company's true carbon footprint.
Take the example of natural gas or electricity: the energy mix varies from one country to another, and sometimes even from one region to another. A kWh in France does not generate the same emissions as a kWh in India.
The same logic applies to purchasing: a kilo of locally produced cotton has a completely different impact from a kilo of imported cotton. The more the emission factors are adapted to the reality on the ground, the more reliable the carbon footprint - and the more useful it is to take action.
Check updates and aim for the right level of detail
An old emission factor can distort results. Technologies evolve quickly, and so do practices. That's why it's essential to check the date of update of the factor used.
Another important point is the level of detail. If it's too global, you lose precision. If it's too complex, collection becomes unmanageable. The objective is a good compromise: a factor precise enough to reflect the realities of the company, but simple enough to remain usable on a day-to-day basis.
Ensure overall consistency... and get support
The right factor is also the one that fits into a coherent logic: with available business data, the company's decarbonization strategy and reporting requirements.
To make this choice more secure, it's best to be accompanied. GCI's experts help companies to select the right emission factors, cross-reference sources and build a reliable carbon footprint in line with standards.
This technical support enables us to gain confidence and credibility... and to move forward more serenely towards an effective decarbonization strategy.