Underestimated potential for greater sustainability in air traffic

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Abu Dhabi Airport has saved 3,000 tons of CO₂ over the past three years – the equivalent of what around 200,000 trees could absorb in a year. And this despite a doubling of passenger numbers during that period. This wasn’t achieved through new engines or synthetic fuels, as such measures are very expensive and time-consuming to implement. Synthetic fuels currently cost three times more than kerosene. In Abu Dhabi, the savings were achieved through a digital assistance system for air traffic controllers in the tower.

An often overlooked lever for decarbonizing aviation lies in the digitalization of air traffic management. Even small improvements in communication and coordination add up to noticeable savings in CO₂ emissions.

43 European airspaces – an obstacle for the climate

Population pressures, national climate targets, and global initiatives like the Paris Agreement are forcing airports and airlines across Europe to take action. They have therefore set themselves ambitious goals. Many aim to drastically reduce their emissions by 2050 at the latest, or even become completely climate-neutral. But with rising passenger numbers, this is becoming more difficult – and time is running out.

A major obstacle lies in the structure of European airspace itself. It is currently fragmented into 43 national sectors, each with its own rules and procedures. In practice, this often leads to longer routes due to detours for aircraft or holding patterns for pilots and passengers. The result: additional, avoidable fuel consumption.

This is precisely where the European initiative SESAR (Single European Sky ATM Research) comes in. It brings airlines, air traffic control providers, airports, and technology providers together to standardize airspace, advance research in air traffic management, and achieve self-imposed climate targets. Specifically, intelligent air traffic management aims to optimize flight routes and procedures, thereby using airspace more efficiently. This reduces fuel consumption—and thus emissions—and also leads to fewer delays.

Digitization instead of new engines

The advantages of intelligent air traffic management are evident in many small but, in total, effective adjustments. One example is the “Follow the Greens” system, where green-illuminated taxiway lights guide pilots efficiently across the airport apron. The system automates the switching of taxiway centerline lights and stopbars, ensuring pilots are always shown the optimal route. Implemented at Abu Dhabi Airports, the system reduces aircraft taxiing times on the ground by an average of 14 seconds per flight. With 820 flights per day, this adds up to significant fuel and CO₂ savings.

At the same time, the pollution from ultrafine particles and ground-level particulate matter is reduced, which is particularly relevant for the health of the population living near airports. According to the European Environment Agency, around 52 million people in Europe are exposed to elevated levels of ultrafine particles near major airports, meaning that even small reductions have a noticeable impact.

Optimized approaches and gliding save fuel.

Another measure is just-in-time approach planning. A digital arrival manager ensures that aircraft are scheduled well in advance of the airport so they don’t have to circle in the air. The arrival manager is based on a unified platform that integrates all flight planning and airport operations systems into a central environment. This platform synchronizes real-time data and workflows between air traffic control, airlines, and ground services, creating a shared, constantly updated overview of all flight movements and resources. Systems of this type are already successfully deployed in London, Singapore, and Hong Kong, reducing holding times by up to 30 minutes.

In conjunction with so-called continuous descent – ​​a smooth glide instead of energy-intensive step flights – additional emission savings are achieved. During descent, aircraft can idle their engines and glide for up to 70 kilometers without consuming additional fuel. Technically, continuous descent is made possible by the close integration of air traffic management systems with weather data, flight plan data, and real-time aircraft location tracking. This data is combined to create individual descent profiles that are dynamically adjusted depending on traffic and weather conditions. The information thus obtained is available to all relevant stakeholders: Air traffic control in the tower receives precise approach profiles and timing specifications to optimally manage the airspace, while pilots receive the necessary waypoints, altitude profiles, and descent times via onboard information systems.

This is only possible if the approach is planned well in advance. According to EUROCONTROL, the European Organisation for the Safety of Air Navigation, this can save 145 kilograms of CO₂ per flight. At the European level, this amounts to approximately 340,000 tons of fuel or 1 million tons of CO₂ annually. Additionally, noise is reduced by up to 5 dB.

Who decides on sustainability in airspace?

Airlines benefit considerably from the savings – through shorter flight times, fewer delays, and lower fuel consumption – but they do not bear the investment costs. The decision regarding acquisition and operation rests solely with air traffic control authorities. In most European countries, these are state-run and dependent on subsidies and investment programs.

The introduction of such air traffic management systems requires significant initial investment. Large airports can usually manage these costs, while small regional airports struggle to do so. Furthermore, there is the conservative safety culture: New technologies must undergo years of testing and certification, such as the EUROCAE standard ED-153 for software safety assurance, before they can be used in regular operations. This is because airspace safety is the top priority.

It is therefore important that policymakers, air traffic control authorities, and airlines work together to advance the digitalization of airspace. Associations like SESAR were created precisely for this purpose.

Sustainability begins in the tower

While many cost-saving measures, such as technical innovations in aircraft or widely available, affordable alternative fuels, are still under development or face hurdles in their implementation, the situation is different for air traffic management systems. These systems are already available and could often be implemented within a few months. This is especially true for airports, where decisions can be made locally and comparatively little coordination is required. This is precisely why tower and airport solutions can deliver rapid and noticeable improvements.

Europe is already taking an important first step with SESAR to promote the standardized implementation of digital assistance systems. The initiative aims for cross-border, interoperable systems that will enable further savings, from takeoff through en-route to approach. This could then allow savings like those achieved at Abu Dhabi Airport to become a model for others.