The Future of Flying: Sustainability in Aviation


Global air travel is busier than ever. Passenger numbers have been consistently high so far this summer, with eight of the top ten busiest travel dates on record occurring in the past month. 23rd June was a record-breaking day with 3 million passengers going through TSA checks in the US alone.

Whilst this is positive for an industry that had a tough few years, it also highlights that the conversation on sustainability is important as ever. Aerospace & defence contributes to 3.8% of global carbon emissions – and aviation players need to take action to bring this figure down.

Due to the stringent safety mandates across the industry, it is difficult to implement new initiatives, and the movement towards sustainable flying will take longer than other transport industries (cars, trains, etc.).

These are several measures that airlines are taking to reduce CO2 emissions, which many are introducing by 2030, as part of the EU Green Deal. In 2021, the European Commission set out targets to reduce greenhouse gas emissions by 90% on 1990’s levels, with the first target to reach a 55% reduction by 2030.

Increase operational efficiency – This may have a limited impact on a smaller scale, but across the 100,000 flights that take off around the world each day, the cumulative impact is positive. The associated fuel savings will also help fund green flying without drastically pushing up ticket prices.

Initiatives such as pilot incentive programmes to fly and taxi more fuel efficiently, or imposing stricter operational weight limits to reduce fuel needs form part of airline thinking.

Bolder moves could affect the customer experiences but would have a greater impact on reducing energy consumption – reducing ultra-long- haul flights, removing some catering on short-haul flights, or densifying cabins to include more seats. Long-haul flights make up 10% of all flights to/from the EU, but contribute to 50% of carbon emissions.

Other efficiency efforts are dependent on collaboration among several airlines, especially to optimise airspace usage. An example of this is the Single European Sky Program, which aims to modernise air traffic control infrastructure to reduce up to 10% of emissions. A similar program called NextGen is underway in the US. These are dependent on participating planes regularly using the affected airspace, so emission reductions could be significantly lower than the target 10%.

Integrated stakeholder action is also needed, with support from outside the airline vertical to drive sustainability improvements:

  • Route Optimisation: it is common for aircraft routing to fly between specific waypoints, frequently adding considerable distance. Improving air traffic control to allow changes to optimise routing for CO2 emissions
  • Increased use of AI to reduce delays at airports and the consequential stacking of aircraft awaiting a landing slot
  • Under EU law, airlines are required to run at least 80% of booked flights to retain their airport slots. The consequent impact of “ghost” flights, where aircraft are flown without passengers to retain the landing slots at prime airports has fallen from the Covid peaks but, depending on the stats you refer to, still accounts for c.500 per month in the UK.

Fleet renewal – accelerated fleet rollover can come at negative carbon abatement cost, particularly when including the impact of regulatory action, such as future SAF mandates and kerosene taxes. Depending on the state of an airline’s fleet, the evolutionary rollover to already available aircraft types represents a decarbonisation potential of up to 15-20%. It is expected that next-generation aircraft, such as the Airbus A320neo or the Boeing 777-X family, will replace a significant share of current-generation aircraft in the next ten years. The A320neo requires 20% less fuel, and the Boeing 777-X requires 10% less. However, not all airlines will be replacing their fleets soon, as this is dependent on the stage in their lifecycle, requiring a balance between replacing less efficient planes and not doing so prematurely, so wasting functioning planes.

Sustainable Aviation Fuel (SAF) – SAF includes synthetic aviation fuels, advanced biofuels and recycled carbon aviation fuels and is by far the most impactful initiative, but financial effects vary due to mandates, subsidies, sourcing, voluntary commitments, and customers’ willingness to pay. Minimum sustainable fuel-blending mandates have been introduced across the EU as part of the ReFuelEU Aviation campaign and by 2025 airports must have a 2% share of SAF. Several airlines have committed to SAF volumes of 10-30% of total jet fuel used by 2030 – totalling about 5% of expected aviation fuel demand in 2030, but by 2050 the EU will require a 70% share of SAF. These requirements are not just for EU countries, but for any airline that wishes to operate out of a member state or refuel at an EU-based airport.

To expand the initiative, the EU-financed ACT-SAF project will conduct feasibility and capacity studies for producing SAF in 13 African states and India. This initiative has grown considerably, with over 90 states and 63 organisations keen to participate in the programme. Over time this will increase production and availability of SAF globally, reducing fuel costs.

However, many airlines still have concerns around the cost, production, and timing of new SAF technologies and raised questions regarding where responsibility for spearheading and paying for these efforts lies. Whilst the EU has put in place practical steps to help air operators reach the targets, c.50% of flights operate outside of the EU and many will not be held to the ReFuel regulations. Elsewhere, the US has proposed tax credits for airlines using SAF, and is planning on introducing funding opportunities for SAF production, but these initiatives have not progressed as far as in the EU.

Whilst SAF prices are high, customers may experience increased ticket costs.  A 2023 McKinsey survey indicated that over 85% of travellers worldwide were willing to pay 2% or more for carbon-neutral flight tickets – a significant increase compared to previous years (46% in 2019). British Airways, United Airlines, JetBlue and Air France have adopted supplementary fees that customers can pay to contribute towards SAF development. These fees are less controversial than the carbon offsetting costs that the Lufthansa group charges customers as part of its green fare offering, and represent a broader change away from ‘greenwashing’ offset programs which are less effective than actually reducing carbon emissions.

The industry still has a way to go to reach net-zero, but it is making tracks towards this goal. In November 2023, Virgin Atlantic made history by flying a Boeing 787 from London to New York powered by a sustainable biofuel made up of waste fats and plant sugars.

With the Farnborough International Airshow taking place later this month, sustainability initiatives will be a key conversation. Polestar is looking forward to joining other attendees in attending sessions dedicated to accelerating the sustainability discussion and highlighting the importance of wider collaboration.

By Annabel Whelan on 03/07/2024