SNCF Gares & Connexions: A Methodology for Calculating Emissions Avoided to Finance Station Renovation Through Green Bonds
Sector
Employee count
5,000 employees, 10 million passengers per day
Location
3,000 train stations
Sales Contact
As the world’s first rail infrastructure manager to issue Green Bonds in 2016, the SNCF Group initially allocated these funds to the sustainable modernization of the network, and subsequently to rolling stock. Train stations, however, were excluded from this scope.
ℹ️ A Green Bond, or a “green” bond, is a debt instrument issued on the financial markets to finance projects that benefit the environment. Rail transportation, one of the modes of transportation with the lowest emissions, is among the eligible activities.
Since 2024, all financing provided by the Group, including loans to its subsidiaries, must be used for projects eligible for Green Bonds.
SNCF Gares & Connexions faced three main challenges:
- Expand the scope of eligible expenses, by demonstrating that maintaining train stations helps sustain rail traffic and thus prevents passengers from switching to cars or airplanes, which produce more emissions.
- Reaching Consensus Within the SNCF Group, in collaboration with the SNCF Group’s Corporate Finance Department and the other subsidiaries, particularly to avoid the risk of double-counting avoided emissions.
- Ensure the credibility of the initiative among investors, using a transparent method that complies with market standards and is verifiable by third parties.
In 2016, Carbone 4 had already developed the methodology for calculating the impact of SNCF Réseau’s Green Bonds. Building on this experience, the firm drew on its expertise in finance and transportation, working alongside the General Secretariat of SNCF Gares & Connexions and the Corporate Finance Department of SNCF SA, in four stages.
1. Defining the Approach
To determine how to incorporate train stations into the Green Bonds program, Carbone 4 analyzed the spending portfolio for the past three years, presented several possible options, and gathered input on the constraints from the Corporate Finance Department (DCF) during a dedicated workshop.
This workshop validated a key approach: view rail stations as an integral part of the rail system, just like the track network and rolling stock. Eligibility is therefore no longer limited to the energy performance of buildings.
2. Identify projects eligible for Green Bonds
Each expenditure category was assigned a Green Bond eligibility rate based on its connection to the regeneration of train stations:
- 100% for renovation, safety, or green stations (lighting upgrades, boiler replacements)
- 50% for accessibility
- 35% for service improvements (furniture, signage)
Certain projects are excluded: those involving stations served only by lines with low ridership or that are not electrified, and the extension of the RER E (EOLE), for which emissions reductions are not guaranteed.
3. Develop a method for calculating avoided emissions
Carbone 4 developed the methodology for calculating avoided emissions. It compares the emissions from two scenarios, and the difference between the two represents the emissions avoided as a result of the investments made:
- Baseline scenario: The lack of investment leads to the gradual deterioration of the station until it closes, at which point passengers turn to other modes of transportation that produce more carbon emissions.
- Project Scenario: These investments extend the station's lifespan, keeping rail traffic at a constant level.
A ratio is applied at the end of the process to allocate the avoided emissions between infrastructure in the broad sense (rail network and stations) and rolling stock.
4. Empower Teams
The firm delivered an automated calculation tool in Excel that enables SNCF Gares & Connexions teams to independently apply the method to their annual portfolio of eligible CAPEX and OPEX.
At the conclusion of the project, SNCF Gares & Connexions has gained three key insights:
- Access to the group's green financing : Its infrastructure renewal projects can now be financed through Green Bonds, just like the network and rolling stock, and not just its energy-efficiency renovation projects.
- A public and verifiable methodology : Methodology "Assessing the Carbon Impact of Investments in Station Renovation" Published in December 2025, it is aligned with those of SNCF Réseau and SNCF Voyageurs and complies with the ICMA Principles.
- An operational tool : The teams independently implement the method each year, from selecting eligible projects to reporting on emissions avoided.
Since its launch, the Green Bonds program has provided funding for the renovation of SNCF Gares & Connexions’ assets in the range of 100 to 250 M€ per year. By keeping stations in operation, these investments help avoid approximately 300,000 to 700,000 metric tons of CO2e per year.
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