How to run a first carbon footprint as a project, not a spreadsheet

Three versions of the scope in two months: France only, then the Spanish subsidiary added, then the leased sites taken back out. None of them was written down or dated, and that is the real reason the report arrived in June.

A first carbon footprint rarely goes wrong in the calculation. Multiplying activity data by an emission factor is arithmetic, and the databases that supply the factors are public. It goes wrong in everything around the arithmetic: the scope that drifts, the data owner who hears about the project the week the deadline passes, the report nobody was assigned to act on. Those are project failures, and project failures have project fixes.

Fix the scope in writing, before anything moves

Answer one question precisely before any data request goes out: whose emissions are you counting? Headquarters only, or every subsidiary? French operations, or the sites abroad? The honest answer usually follows your legal and operational structure, because that is the boundary your future reporting will use and the one an auditor or a customer will recognize.

Then set out the three scopes of the GHG Protocol, the accounting standard behind nearly every corporate greenhouse gas (GHG) inventory:

• Scope 1: direct emissions from what you own or control, such as fuel burned in company vehicles or gas boilers, and refrigerant leaks.
• Scope 2: indirect emissions from purchased electricity and heat.
• Scope 3: everything else along the value chain, from purchased goods and freight to business travel, commuting, and the use of what you sell.

Write it down, date it, and have your sponsor endorse it. A scope that exists only in the project manager's head is not a scope, it is an opinion, and it will be renegotiated by every department that finds its own data inconvenient.

Good to know: above 500 employees in mainland France (250 in overseas territories), the regulatory greenhouse gas report (BEGES) is not optional. Since décret 2022-982 took effect in January 2023 it must cover significant indirect emissions, meaning scope 3, and in October 2023 the penalty for not filing was raised to up to €50,000, and €100,000 for a repeat offense. The four-year filing cycle passes faster than it sounds.

The people set the timeline

Your data lives in other departments. Energy invoices sit with facilities or accounting. Headcount and commuting sit with HR. Purchase lines sit with purchasing or finance. Fleet fuel sits with whoever manages the vehicles. None of these people report to you, and every one of them has another job that does not pause.

The most effective single decision in the project is to appoint one named contact per department, agreed with their manager, with a defined perimeter. That person answers for their data, chases it internally, and attends two meetings: a kickoff and a mid-collection review.

Hold the kickoff before the first data request goes out. Say what the exercise is, why the company is doing it now, what each contact owes and by when. Someone who understands that purchase data drives most of the result treats the export request differently from someone who received a spreadsheet by email with no explanation attached.

Choose the route for year three

There are three ways to get a footprint done, and none is wrong in itself.

• Train someone in-house. A team member takes a recognized course, such as the Bilan Carbone training, and builds the footprint internally. Slowest to start, and the expertise stays.
• Hire a consultancy. Fastest to a defensible result, at the price of a budget line and of knowledge that partly walks out when the engagement ends.
• Use software. Guided collection, maintained factor databases, calculation handled for you. The quality of the result still depends entirely on what your departments provide.

The question that decides it is not this year's. It is who produces the second and third footprint, because a first assessment is only a baseline and its value appears when the next one shows movement. If the answer is "the same consultancy, again, from scratch," you have bought a report rather than a capability.

Let collection take the room it needs

A realistic first-time sequence has four phases: framing, collection, analysis, action plan. Framing is a few weeks of decisions. Analysis and the plan move quickly once the data is in. Collection is the phase that stretches, and it is the one phase you cannot rescue by working harder at the end, because the waiting sits on other people's calendars.

So start it first and run it in parallel across departments, tracked like any other dependency list: what was asked, from whom, promised when, received or not. The mid-collection review exists to surface stuck sources while there is still time to unstick them.

What the report owes its reader

Make it something someone can act on next quarter. Each major emission source traceable to the activity data behind it, the factor applied, and the method used where the figure was estimated. And name the weak points, because a first footprint always has them; a confident total quietly resting on an extrapolated purchase line poisons the baseline you will measure year two against.

So publish it honest, reproducible and finished, rather than perfect. A first carbon footprint that is none of those three has to be redone, and one that is all three lets the real work start.

FAQ

Is a carbon footprint mandatory in France?

For companies with more than 500 employees in mainland France (250 in overseas territories), the regulatory BEGES report is mandatory every four years, and since January 2023 it must include significant indirect (scope 3) emissions. The penalty for failing to file can reach €50,000, and €100,000 for a repeat offense. Smaller companies have no general obligation, but customers and banks increasingly ask for the figures.

How long does a first carbon footprint take?

Count in months rather than weeks, and expect data collection to occupy most of the calendar. Framing takes a few weeks of decisions and analysis moves quickly once data is in, but collection depends on other departments producing invoices, exports and headcounts. That is why it should start first and run in parallel.

Should a first footprint be done in-house or with a consultancy?

Decide based on who will produce the second and third footprint. External support reaches a defensible baseline faster; in-house training keeps the capability in the company. Either way the data comes from your own departments, so the network of internal contacts is required in both cases.