Air France chairman and chief executive Jean-Cyril Spinetta is welcoming French rail operator SNCF’s initiative of showing per person carbon emissions on its website, but is planning to challenge its rail and air comparisons.

SNCF launched a new scheme under which it displays a journey-based comparison between air, car and rail carbon emissions alongside its prices during the booking process.

Speaking during the Cannes Airline Forum, Spinetta said: “I’m glad that SNCF has taken this initiative and we will be able to start open discussions and compare carbon dioxide emissions between aircraft and trains.”

Spinetta says the SNCF comparisons show carbon emissions from rail to be thirty times lower than travelling by air, but he argues that the environmental impact of the fossil fuels used to generate electricity must be taken into account in the calculations.

He contests the accuracy of the figures, which are backed by French environmental agency Ademe, claiming that an Airbus A320 produces around 20-40% fewer grams per person than shown.

The Air France-KLM chief says: “We are going to be in discussions with Ademe about this. We are going to have a debate with SNCF and get down to the real figures. When we communicate to the customer we have to give precise and exact information.”

Ademe says: “It is very complicated, so that is why you can attack the way that it is calculated. I don’t know what Ademe is going to say about that. We are doing this in partnership with so we are pretty sure of the way that we have calculated the numbers.”

Spinetta highlights the environment as being “the issue” for airlines going forwards.

Beyond the environmental debate Air France is still keen to pursue any opportunities arising from rail liberalisation in France.

Spinetta says: “Once this industry is liberalised Air France will operate trains. We wouldn’t do it ourselves, we would sign specific agreements with operators to charter trains. I am waiting with great impatience for the day when the market becomes deregulated.”

But he rejects the idea of airport-based rail hubs, saying that effective air-to-rail security would be expensive and adding that trains offer too much capacity to be filled by airlines operating to slot-restricted airports.