8 September 2022
Authors : Nicolas Meunier

Towards sufficiency in the aviation industry

Overlooked earlier this summer, a significant development has taken place in aviation industry. As the aviation industry in Europe struggles to cope with a traffic recovery that exceeds all expectations of a return to pre-COVID levels, the Dutch government has announced plans to restrict the number of authorized takeoff slots at Amsterdam Airport to 440,000 per year starting November 2023. This is a 12% reduction from the current limit of 500,000[1].

Schiphol airport is the top airport in Europe and ninth busiest in the world, making this decision a significant step towards greater climate maturity in the aviation sector.

The decision to reduce air traffic at Schiphol airport was primarily driven by concerns over noise and air pollution (NOx), which were outlined in agreements made with residents of the Amsterdam metropolitan area. However, climate change is also mentioned and undoubtedly part of the decision[2].

Previously, the Dutch infrastructure minister had proposed an increase to 540,000 slots per year in 2019, but the government has taken a measured approach and even postponed the decision of allowing another Dutch airport to start commercial operations until summer 2024.

This move towards reducing air traffic is a sign of growing climate maturity within the aviation sector, following the abandonment of airport extensions such as Notre-Dame des Landes in Nantes in 2018 and Terminal 4 at Roissy-Charles de Gaulle in 2021.

This measure is noteworthy, as this measure focuses on sufficiency, i.e. traffic reduction, which has been a taboo lever in aviation.

Until now, the main climate measures deployed by aviation have focused on energy efficiency, such as fleet renewal and eco-driving, which can easily lead to a rebound effect (the less we consume, the more we can fly with the same amount of kerosene). The decarbonization of the energy sector has also been a recent development, with the emergence of sustainable aviation biofuels and e-fuels. However, aviation sufficiency certainly cannot be ignored to achieve a 2°C target, as shown in the graph below.

Evolution of CO2 emissions (combustion only) of global air transport (excluding regional), respecting the 2°C budget defined by ISAE Supaéro
Even in the very optimistic case of a strong development of technological levers and a production of alternative fuels equal to the current kerosene consumption (~300 Mt), a moderation of growth is necessary to respect the carbon budget.

Limiting the number of takeoff slots is a simple and effective approach to reducing aviation emissions. However, this does not guarantee a decrease in aviation activity (measured in or emissions. One unintended consequence of this approach is that it may lead to the replacement of short-haul flights with longer, more lucrative ones. While larger aircrafts with greater carrying capacity are more carbon-efficient per, the flights are more CO2-emitting. Nevertheless, limiting the growth of emissions through slot constraints is beneficial as it limits take-offs of both short- and long-haul flights. This constraint naturally encourages the removal of flights for which there are alternatives by bus or train. Furthermore, it encourages the optimization of aircraft capacity utilization (even though airlines are already working hard on this) and therefore energy efficiency.

Achieving growth moderation, without discussing reduction, poses a significant challenge for the aviation industry and other sectors like road transport of goods and people. The resistance to this change is understandable, as aviation ecosystem and our economy have been fixated on endless growth for decades. This resistance is tied to an idea of progress and societal well-being. However, the climate crisis and finite resources demand a reevaluation of this goal. The challenge ahead is monumental - balancing traffic moderation and equity (between nations, between passengers of the same country, based on their reasons for travel, etc.) while simultaneously investing in decarbonization technologies. The 20th century was witness to the aviation industry's remarkable ability to overcome challenges, transforming it from an unattainable dream to a mature industry. As we face the challenge of the end of growth, let us bet on the aviation industry's actors to rise to the occasion once again.

Despite the significant benefits of this sufficiency measure, the Dutch national airline KLM, the manager of Schiphol airport, the federation of airlines IATA, and others are currently opposed to the measure from the Dutch government. This resistance highlights the significance of political decisions in meeting climate objectives. Let's hope that this sufficiency measure will ultimately be Implemented!