SNCF pinned on the compared carbon footprint of the train and the plane

SNCF will have to review some of its advertisements concerning CO emissions₂ comparison of the train and the plane. If the train is indeed the least CO2-emitting mode of mass transport₂the Advertising Ethics Jury (JDP) seized of a complaint from the National Federation of Aviation (FNAM), estimated that SNCF advertisements, according to which “travelling by high-speed train is 50 times less CO₂ issued only for travel by car and 80 times less than by plane”, were likely to mislead the public.

More specifically, the JDP writes in its opinion that the two SNCF advertisements called into question by the FNAM – the one appearing on a press file and the same message affixed to its engines -, “disregard points 2 and 4 of the Recommendation “sustainable development” of the Professional Advertising Regulatory Authority (ARPP)”. Namely: “not to mislead the public about the reality of the advertiser’s actions or about the properties of its products in terms of sustainable development” (point 2) and formulate a clear message, indicating “how its activities or its products have the qualities claimed” (point 4).

A dubious average

The JDP does not decide on the merits: namely the reality of the figure of “80 times less” put forward by the SNCF and disputed by the FNAM. He is content to point out that, by the SNCF’s own admission, this ratio of “80 times less” “must be understood only on average, over all long-distance journeys in France”. It notes “in addition that the sources and methods of calculation used to arrive at the alleged figure appear in very small characters, which are difficult to read”.

This allows the SNCF to refute the accusation of false advertising. “The ARPP does not question the relevance of the ratio of around 80 times less emissions by TGV than by plane, which was a calculation by Ademe on the date of our communication, but simply recommends specifying that “This is an average since, depending on the route, this differential can be more or less 80”, underlines a spokesperson for the SNCF, who adds that this advertisement had been validated in its time, by the ARPP.

SNCF “does not want to argue”

“We will comply with the opinion of the ARPP, to specify that this is an average”, nevertheless announces the spokesman of the SNCF. “In addition, we are obviously updating our communications according to the evolution of the Ademe calculation basis, which now sets a ratio of on average 65 times less CO emissions₂ by TGV than by short-haul plane”. “We have no desire to argue and feed rearguard battles,” says the SNCF.

In fact, the figures put forward by the SNCF and the comparisons with the plane are nonetheless very questionable. In 2022, Ademe had already had to review its CO comparison₂, which presented huge discrepancies with other computers, increasing the balance sheet of the aircraft. This change in calculation had led Ademe to revise upwards the carbon impact of train travel, thus reducing the average differential with the plane from 80 to 50.

Big discrepancies between CO2 calculators

Nevertheless, large differences remain between the Ademe comparator and that, just as official and more precise, of the Ministry of Transport. So for a Paris/Toulouse, the Ademe simulator advances the figure of 135 kg of CO₂ per passenger for the plane, against 1.9 kg for the TGV (and 4.9 kg for the Intercités trains), while that of the General Directorate of Civil Aviation (DGAC) gives 66.7 kg of CO₂ per passenger for a Paris/Toulouse flight, to which the site even adds 12.7 kg of CO₂ for the operations necessary for the production and distribution of fuel. And this, on the basis of an average consumption of 4.6 liters of kerosene per 100 km per passenger, whereas the most modern aircraft, such as Air France’s Airbus A220s are rather at 2.6 liters.

On his side, the SNCF comparator poster for the same Paris-Toulouse, 1.7 kg of CO₂ for the train, limited to the TGV, and 77 kg for the plane. However, none of these figures include the carbon footprint linked to the construction and maintenance of infrastructures, which are obviously much more important for the train than for the plane.

A European study concluded that the environmental impact of a high-speed line is such that it takes at least ten years to compensate for CO2 emissions.₂ produced during its construction.