A few days ago France introduced a ban on short-haul flights, proposing that travelers on routes under 2.5 hours should switch to trains. The move makes France the first country to adopt such a measure aimed at lowering pollutant emissions. Adeline de Montlaur, an aeronautical engineer and professor at the Polytechnic University of Catalonia, collaborated on a study released in 2021 assessing how short flights impact CO2 emissions. The findings show that short flights generate more emissions per passenger than longer ones.
-How much do short flights under 500 kilometers pollute the environment
That depends on what metric is being used. When looking at the share of contamination among all flights, the impact seems small. Yet when comparing per passenger per kilometer, short trips can be far more polluting than long ones. The research indicates this pattern. Eurocontrol figures, representing industry data, put emissions at about 3.4 liters per passenger per 100 kilometers on average. But this averages across all flights, and on short trips it is common to see roughly double that consumption. On some short routes, the figure can reach around 6 liters per passenger per 100 kilometers. The exact value depends on aircraft type and other variables.
-Why does this difference arise
It comes down to the energy cost of takeoff. Lifting off consumes a lot of fuel, more so than cruising once a level flight is established. Short flights must climb quickly, reach cruising speed, and then descend soon after landing. That immediate climb and descent means a higher proportional share of fuel is used during takeoff for shorter trips. In other words, takeoff has a larger impact on total fuel use for short durations than for long flights.
“Proportionally, the takeoff of a short flight uses more fuel than a long flight”
Another factor considered in the study is the ground portion at the airport runway. While not the largest consumer, data from 2022 shows that taxiing and related engine use account for about 15 percent of total flight time in Europe. At major European hubs, the total taxi time can add 20 to 30 minutes to a flight’s overall duration. When the aircraft is rolling on the ground, fuel is burned. Those minutes can weigh more heavily on a shorter journey than on a longer one when considering overall emissions.
Does this happen on all planes
In a broad sense, the trend is toward more efficient aircraft. Manufacturers continuously improve engine efficiency and airframes. Yet overall emissions rise because air traffic grows faster than efficiency advances. In short, technology is helping, but it does not automatically offset the growth in total emissions.
Could the short-flight ban in France really reduce emissions
The core idea originated from a citizen assembly of 150 people tasked with proposing solutions. The plan allows an alternative to short non-stop flights by train on routes up to a maximum of 4 hours, with the threshold later tightened to 2.5 hours. In practice, only a limited number of routes feel the impact, mainly those connecting Paris Orly to Nantes, Bordeaux, and Lyon. Connecting flights are not completely excluded, but many routes that disappeared during the Covid period could vanish altogether. The European Union welcomed the measure and suggested that the ban should extend to Charles de Gaulle if connections through that hub rely on train links with sufficient frequency, ensuring travelers from the United States do not face long layovers. Whether the measure will have a wide effect remains to be seen. It provides a concrete example that raises awareness, though some argue that more routes should be included to maximize impact.
“The French law is a good start but should cover more flights, including connections”
Explaining further, it is not a simple issue. The door-to-door time matters more than the flight duration alone. Leaving home and arriving at a business meeting in Madrid should be comparable for train and plane travel, and in some cases trains can even beat planes on total travel time. The debate continues over how to balance convenience, time, and environmental goals while ensuring viable alternatives exist.
-Are rail costs competitive with air fares
Price plays a big role. From Barcelona to Madrid, a train ticket can be attractive, but historically airfares have often been cheaper, aided by fuel subsidies. Taxes apply differently to aviation fuels than to road fuels, a discrepancy many observers find hard to justify in a climate emergency. Public subsidies for rail are real, but the question remains whether aviation should face similar fiscal measures. The broader issue is global rather than a single nation’s problem, and it invites coordinated European policy.
Many proponents argue that the aviation sector must become significantly more expensive to reach zero emissions by mid-century. Is that how it will unfold
The industry has laid out a plan toward zero emissions by 2050 that hinges on a mix of technology improvements, sustainable aviation fuels, and offsets. However, skeptics point out that the price tag for sustainable fuels is high and unlikely to drop quickly. If the plan proceeds as proposed, higher ticket prices may be the natural consequence. Critics question whether such a pathway can realistically meet the 2050 target without substantial and sustained policy support.
“The aviation industry’s 2050 zero-emission goal may not be viable without major changes”
Commentary from industry observers notes that the cost of sustainable aviation fuel often exceeds conventional fuel, and prices may not fall significantly due to the way it is produced. If these plans advance, ticket prices are likely to reflect the extra cost. The path forward remains debated, with strong opinions on whether greening aviation is feasible within the current economic framework.
Would the French model work in other countries
Policy is inherently political and will. Airlines typically resist unilateral disruptions because they affect schedules and profitability. Some analysts suggest extending the 2.5 hour limit to 3 or 4 hours might yield greater benefits while preserving essential connectivity. A broader, Europe-wide approach could have a larger impact, but it would require coordinated action across member states and robust rail networks to keep door-to-door times competitive.
Reference work: MDPI sustainability study on transport emissions across short flights and mitigation options, cited here for attribution to the original research. (Source attribution: MDPI Sustainability, 2021)
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End of summary notes on policy and emissions considerations for short-haul air travel.