A Bilan GES may follow different methodologies or carbon accounting standards, but generally follows the same process:
- List the activities induced by the company. - Collect activity data (products purchased, fuel consumption, heating of premises, etc.).
- Convert all activity data into a common unit, the CO2e, which enables the carbon footprint to be quantified. Each activity data value is multiplied by an Emission Factor which quantifies the CO2e value of a unit of activity (CO2e / kWh, CO2e / liter, CO2e / km.passenger, etc.). Today, there are many public and private emission factor databases, such as the one provided and maintained by ADEME. It is also possible to use emission factor data from life-cycle analyses carried out specifically for a product.
- Categorize the company's various emission items under
Scopes 1, 2 and 3: direct emissions under Scope 1, indirect emissions associated with energy consumption under Scope 2, and indirect emissions (e.g. its purchases of raw materials) under Scope 3.
- Add up all the values for the various emission items, expressed in CO2e. This sum of emissions, classified by emissions scope and sub-categories (which may vary according to
carbon accounting methodologies), constitutes the measurement of the company's carbon footprint, and is a prerequisite for the implementation of an environmental transition plan.
