France has banned air travel between cities that can be reached easily by train

• France banned air travel between cities that are 2.5 hours apart by high-speed rail on May 23.
• The rail connection has to be frequent enough to allow someone to go back and forth in a day.

If you're in France, you'll have to take the train.

On May 23, a French law officially went into effect banning air travel between cities that can be connected by a 2-and-a-half-hour train ride.

For the air travel ban to take effect, the two cities have to be connected via high-speed rail, and the connection has to be direct and affordable.

Additionally, it has to be frequent enough that a traveler can make the trip back and forth on the same day, and spend 8 hours in the city.

At the moment, the ban only affects the routes between Paris' Orly Airport and the cities of Bordeaux, Nantes, and Lyon, which are prohibited for any carrier. It might affect more routes in the future as rail connection improves.

"As we fight relentlessly to decarbonize our lifestyles," Clement Beaune, France's transportation minister, said in a statement. "How can we justify the use of the plane between the big cities which benefit from regular, fast, and efficient connections by train?"

France has a robust and expanding high-speed rail network, with the French National Railways in the process of rebooting its TGV trains and extending its network.

The measure was first approved in 2021 as part of a broader climate bill that targets a reduction in carbon dioxide emissions, of which aviation accounts for 2.5% globally.

The original proposal was supposed to affect eight routes, but the European Commission later ruled that trips between Paris-Charles de Gaulle and Rennes; Paris-Charles de Gaulle and Lyon; Paris-Charles de Gaulle and Nantes; Paris-Charles de Gaulle, and Bordeaux; and Lyon and Marseille are not short or frequent enough to qualify yet.

Given the scope of the ban, some critics have pointed out that the measure is largely symbolic. Laurent Donceel, the interim head of Airlines for Europe, told AFP lawmakers should focus on "real and significant solutions" instead.

In his statement, the transportation minister Beaune did describe the measure as a "symbol," but added it's a strong one, the first of its kind, and an "essential step" in the right direction.