Everyday action · tip no. 2
Take the train instead of flying: the most effective way to travel
Per kilometre travelled, a French high-speed train emits dozens of times less greenhouse gas than a plane. For trips within France and Europe, choosing the train is often the most effective action of the year.
If you fly, it is very likely your biggest lever for reducing your carbon footprint. A single long-haul return flight can represent a considerable share of the annual footprint of a person in France, which is between 8 and 9 tonnes of CO₂ equivalent. And for the same journey within France or Europe, the French high-speed train (TGV) emits, per passenger and per kilometre, dozens of times less greenhouse gas than a plane, according to data from ADEME, the French agency for ecological transition.
Why flying weighs so heavily
Distance and speed
The first factor is simple: planes let us cover in a few hours distances we would never travel otherwise. A Paris–New York return trip is about 12,000 km; a return trip to South-East Asia, more than 20,000 km. Even with a modern, full aircraft, these distances translate into hundreds of kilograms, or even several tonnes, of CO₂ equivalent per passenger.
Kerosene, burned at altitude
A plane burns kerosene, a fossil fuel. Every litre burned releases CO₂. But that is not all: at altitude, engines also emit nitrogen oxides and water vapour, which form contrails and sometimes artificial clouds. These so-called "non-CO₂" effects also warm the atmosphere in the short term. That is why ADEME and many calculators count higher emissions per kilometre than CO₂ alone, often around double.
Take-offs and landings
On a short flight, take-off and climb, which use a lot of fuel, make up a large part of the trip. Per kilometre, a short flight therefore often emits more than a long one.
What the data say
Emission factors vary between sources, years, load factors and whether contrails are included. The orders of magnitude published by ADEME and used by most comparison tools are as follows, per passenger and per kilometre:
- Short- or medium-haul flight, contrails included: around 200 to 260 grams of CO₂ equivalent;
- Petrol or diesel car with one person on board: around 200 grams, less if shared;
- TGV in France: around 2 to 3 grams, thanks to French electricity being largely low-carbon (nuclear and renewables).
So the high-speed train emits, per kilometre, dozens of times less than a plane. Even when the construction of tracks and trains is included, the gap remains considerable. In other European countries, where electricity is more carbon-intensive, trains emit more than in France, but generally remain far below planes.
How to do it in practice
1. Within France: make the train your reflex
For most large French cities connected by TGV, the train is competitive in door-to-door time: it leaves from and arrives in city centres, with no security checks or baggage wait, and lets you work or rest during the journey. On routes such as Paris–Lyon, Paris–Bordeaux or Paris–Marseille, flying rarely saves time once all these factors are counted.
2. Within Europe: the train, by day or by night
London, Brussels, Amsterdam, Geneva, Barcelona, Milan and Frankfurt can be reached by train from Paris in a few hours. For more distant destinations, night trains are making a comeback in Europe: you leave in the evening, sleep, and arrive in the morning, saving a night in a hotel. Planning a few weeks ahead often helps you find good fares.
3. For long trips: less often, for longer
For destinations outside Europe, flying is often the only realistic option. The lever then becomes frequency:
- travel less often but for longer: one big trip every two or three years rather than several short long-distance stays each year;
- choose direct flights, because each extra take-off increases fuel use;
- fly economy: a business-class seat takes up more space on the plane and is therefore allocated more emissions.
4. For business travel
Many meetings can be held by video call. For the others, many companies have adopted simple rules, such as mandatory train travel below a certain journey time. You can suggest this kind of rule in your organisation.
5. Rediscover nearby destinations
France and its neighbours are full of destinations you can reach by train: mountains, coastlines, big cities, nature parks. The journey itself can be part of the holiday.
Misconceptions to avoid
- "The plane is leaving anyway, whether I am on it or not." For a single flight, that is true. But airlines adjust their capacity to demand: fewer passengers eventually means fewer flights.
- "I offset my flights, so they don't count." Offset projects can be useful, but their quality varies greatly and they do not erase emissions already in the atmosphere. Avoiding a flight remains safer than offsetting it.
- "Electric planes are just around the corner." Research is under way, but electric or hydrogen aircraft able to carry many passengers over long distances are not expected for many years.
In short
- Flying is often the largest source of emissions for people who travel regularly.
- Per passenger and per kilometre, the TGV emits dozens of times less than a plane, according to ADEME data.
- In France and Europe, the train is often competitive in door-to-door time.
- For long trips, travelling less often but for longer makes the biggest difference.