France has banned short-haul domestic flights. How much it will help combat climate change is up in the air.

Paris – France has passed a law banning some domestic flights and encouraging travelers to take the train instead. Under the new law, flights that can be replaced by a train journey of under two-and-a-half hours should be scrapped.

The ban on short-hop flights became law on Tuesday. However, France’s national airline had already canceled three routes that were deemed too high on carbon emissions. All three went from Paris’ second airport, Orly, serving Bordeaux, Lyon and Nantes. Those three cities are all on the country’s extensive high-speed rail network, and taking the train is also far faster than flying there.

Air France agreed to drop those direct routes in return for coronavirus financial assistance from the government in 2020.

Critics say the ban will have a negligible effect on carbon emissions. Laurent Donceel, interim head of industry group Airlines for Europe, which represents several airlines including Air France, KLM, Lufthansa and Ryanair, dismissed the law as a “symbolic ban.” He told the Agence France-Presse news service that governments should instead support “real and significant solutions” to airline emissions.

While the ban sounds like a good idea to help combat climate change, in fact there are a number of caveats that severely limit its scope. The replacement train service must be frequent, timely and allow travelers to get to and from their starting point in the same day while allowing them a full eight hours at their destination.

The choice of train station designated as the departure point has also strangled plans to limit short-haul flights from Paris’ main airport, Charles de Gaulle. The comparative train station is the one at the airport — which has a much more limited service than the seven mainline stations in Paris itself.

That has meant that while you can’t fly from Orly to Bordeaux direct, you can fly to the southwestern wine city from CDG. In fact, the only routes that will be affected by the ban are the three from Orly that no longer operate.

An exception in the ban allows flights with a transfer to continue to operate, and that has led to some convoluted routes that take much longer than a direct flight or a train — and mean even more harmful emissions in takeoff and landing.

For example, the direct route from Paris to Lyon in eastern France, capital of gastronomy and a business hub, used to take under an hour from Orly. That route has been canceled as it was considered wasteful. You can still fly from Orly to Lyon — but you have to fly via Nice, in the south, changing planes to hop back up to Lyon, for a flight time of three hours, 15 minutes.

By contrast, a high-speed train from Paris will have you in central Lyon in just two hours. Or you can still fly direct in over an hour from de Gaulle. However, the total journey takes considerably longer when you add in the trip to and from the airports, checking in and going through security checkpoints.

The quest for lower emissions has led European airlines to examine a number of options. Air France recently announced plans to renew its fleet in an effort to cut carbon emissions. It says it will also increase its use of sustainable aviation fuel.

The airline already has a train and air partnership with France’s national rail company SNCF in a bid to reduce carbon dioxide emissions. It allows travelers to combine plane and train reservations in one booking, essentially allowing people to quickly and easily compare methods of travel.

Aviation news website Runway Girl Network reports that Spanish airline Iberia is currently expanding its flight and train combination offer. Dutch airline KLM is buying up seats on high-speed trains from Schipol airport in Amsterdam to Brussels in a move to drop one of its daily flights between the two cities.

When the ban was first raised as part of France’s 2021 Climate Act, Transport Minister Clément Beaune called it “a major step forward in the policy of reducing greenhouse gas emissions.”

“I am proud that France is a pioneer in this area,” he added.