EUROCONTROL’s Think Paper on air and rail balance & the European Environment Agency’s reaction

Thinkpaper 11

EUROCONTROL’s Think Paper on air and rail balance examines the implications an increased shift of air traffic to rail would have. In our third edition of the Aviation Sustainability Briefing we summarise the key findings and welcome François Dejean from the European Environment Agency sharing his thoughts on our Think Paper.

The possibility of shifting air traffic to rail in order to reduce transport emissions and achieve carbon neutrality by 2050 has become a frequent suggestion in the political decarbonisation discussion.

To ensure an informed debate EUROCONTROL recently produced a Think Paper called “Plane and Train: Getting the Balance Right” examining the environmental, economic and societal implications an increased shift to rail would have as part of a wider green, smart and affordable mobility approach. The Paper explores the consequences of a potential substitution of short distance air travel by high-speed rail (HSR) and reveals the lack of data that prevents a thorough HSR/air comparison, in particular on the cost, actual capacity and environmental impacts of the HSR infrastructure.

While air and rail have a natural complementarity that should be capitalised on, shifting air to rail is not the silver bullet for curbing emissions. Even where a massive replacement of air travel by high-speed rail is feasible – below 500-1,000 km distance – this would only result in 2-4% gross CO2 emissions savings, as pointed out by environmental NGO Transport & Environment. Although this is not negligible, it is disproportionate compared to the strong focus air-to-rail shifting policies are currently receiving in the public sphere, that risks distracting the attention of policy-makers from the real opportunities for decarbonising aviation.

The limited potential effect of air-to-rail shifting strategies is partly explained by the small percentage short-haul flights represent within total aviation emissions: in Europe, flights below 500 km account for 24.1% of European flights but only 3.8% of aviation’s gross CO2 emissions. Furthermore, these potential CO2 savings do not materialise when not meeting passengers’ expectations in terms of price or speed.

Airplane flying over a train


This 11th issue covers Plane and train: Getting the balance right.

High-speed rail costs twice as much as air and is 10 times more damaging to land use

What are the consequences if trips by plane below 1,000 km were to be replaced by trains? In the absence of public studies assessing how much railway extension this would require, we have used the UIC publication ‘High Speed Lines in the World 2020’ that reports that 10,000 km of new HSR lines are currently planned in Europe. This can be seen as a fair reflection of the plans of the European railway sector, although it does not specify if these are in line with the ambitions of the European Commission’s Sustainable and Smart Mobility Strategy of doubling HSR traffic by 2030 and tripling it by 2050.

Building 10,000 km of new HSR lines would cost approximately €250 billion, using the calculation methodology provided in the Handbook on the External Costs of Transport. Building 10,000 km of new high-speed rail lines will result in 30,000 hectares of biodiversity loss, a significant negative impact of railway development, which is often underestimated.

Aviation decarbonisation will be well underway by the time HSR infrastructure is deployed

Although train has clear advantages over plane in terms of emissions today, considering that new HSR lines tend to take between 18 and 26 years to build, the question is whether shifting air to rail will be an effective way to meet the objectives of the EU Green Deal in 2030-2050? By that time, aviation decarbonisation will be well underway, thanks to sustainable aviation fuels and investments in new propulsion technologies such as electric, hydrogen or hybrid aircraft that should be market ready by then. Setting the air-rail balance right when defining policies today is therefore essential for aviation to be able to raise the necessary funds, especially in times of strong competition for financial resources and cleaner energy.

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HSR cannot equal air connectivity, but it can play a key role in developing air-rail multimodality

Air travel offers more flexibility and wider connectivity than HSR in all situations, and it remains vital to the European economy. Replacing air by rail may also have social implications that require case-by-case analyses. Finally, complementarity can sometimes bring more than competition, as shown by multiple cases of air-rail multimodal partnerships across Europe, revealing an untapped potential for multimodality, at lower cost and preserving connectivity to the benefit of passengers.


At the beginning of the year, the European Environment Agency (EEA) published a “Train or plane?” report which assesses the value of travel by train and plane, and which was one of the sources for our Think Paper “Plane and train: Getting the balance right”. François Dejean, Head of Group Climate Change Mitigation, Energy and Transport at EEA shares his comments on our Think Paper and EEA’s current activities.

What are your views on the findings of our Think Paper in general, and more specifically on the untapped potential of multimodality around airports?

The better the different modes of transport are linked, the greater the opportunity for optimising the environmental performance of the entire mobility system. Exploiting the strengths of individual modes is key to making Europe’s mobility system more sustainable. Our own report on the environmental consequences of rail and air travel calls for developing complementarity between them. Major airports should be connected to the high-speed rail network. Currently, many airports in Europe are still mainly served by road links. This limits the opportunity for replacing short-haul feeder flights with trains.

Concerning the air-rail debate, we share your finding that data are missing, preventing a thorough full lifecycle sustainability analysis of the air-to-rail shifting strategies. What is your approach for dealing with this issue, and what would you recommend for the future?

We need to further improve the knowledge base. Improving the statistical system, especially for passenger rail travel, would be an important step in this context. Good information on life-cycle aspects is already available at the level of some infrastructure projects and individual countries have developed relevant methods. What is still lacking is a harmonised approach across European countries, and the data for enabling a full life-cycle analysis at European level. Closing these gaps should be a priority.

Concerning the issue of competition between transport modes, i.e. the race towards decarbonisation by 2030-2050 and the competition for funds and greener energy, what would you expect from these industries?

The energy and the mobility system are closely linked, and clean energy supply is vital for transport decarbonisation. For the EU to achieve climate neutrality, the European Green Deal foresees that the transport sector should reduce its emissions by 90% compared with 1990. Meeting that objective means that all modes of transport need to become more energy efficient and that focus should be on further developing the forms of transport with the lowest emissions. There is a clear role to play for the aviation sector to contribute to this effort.

Finally, could you tell us briefly about EEA’s mission and how you see your role evolving to support the ‘Fit for 55’ package about to be issued by the European Commission?

The EEA aims to support environment and climate actions under European policies, the European Green Deal, as well as Europe’s global commitments. We provide data and information on Europe’s environment and climate to European citizens and policy makers. For example, we compile every year the EU greenhouse gas emission inventory, which provides a detailed overview of emissions in the transport sector. For road transport, we monitor average CO2 emissions from new vehicles and the life-cycle CO2 emissions of fuels sold in the EU. We also track emissions from aviation under the EU ETS and we regularly assess progress towards policy targets. We also develop knowledge on solutions to address sustainability challenges, including in the mobility system.

Regarding the ‘Fit for 55’ package, the EEA will carefully analyse the upcoming proposals from the Commission. We anticipate that our role to support some of the legislation covered by the package will continue. We will also explore opportunities to further improve our understanding of the interlinkages within and between the broad-ranging policy areas that the package will cover.

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