Sustainable Aviation Fuels: Reducing the Carbon Footprint of Air Travel in Europe
Sustainable aviation fuels (SAF) are rapidly emerging as a critical solution to decarbonize the aviation sector and curb its significant climate impact. With air travel demand projected to grow, particularly in developing economies, the need to find clean alternatives to conventional jet fuel has never been more urgent.
The Necessity for Sustainable Aviation Fuels
Aviation currently accounts for around 2-3% of global greenhouse gas (GHG) emissions annually. However, this figure does not capture the full climate impact of air travel, which also includes the warming effects of contrails and other non-CO2 emissions. Experts estimate the total climate impact of aviation to be two to four times higher than the effect of its past carbon dioxide emissions alone.
Without intervention, the aviation sector’s emissions could rise to as much as a quarter of the world’s total emissions by 2050. This trajectory is simply unsustainable if Europe and the global community are to achieve their ambitious climate targets. Decarbonizing aviation is a complex challenge, as the sector’s heavy reliance on energy-dense liquid fuels and long aircraft lifespans make it notoriously difficult to electrify or rapidly replace existing fleets.
Sustainable aviation fuels offer a critical pathway to reduce emissions from the air travel industry today. SAF are drop-in replacements for conventional jet fuel, made from renewable biomass, waste resources, and synthetic feedstocks. When compared to fossil jet fuel, SAF can deliver lifecycle greenhouse gas emissions reductions of up to 80% or more, depending on the production pathway.
Technological Advancements in Sustainable Aviation Fuels
The aviation industry has made significant progress in developing and approving various SAF production technologies. Hydroprocessed esters and fatty acids (HEFA) pathways, which convert used cooking oils and animal fats into jet fuel, currently represent the most mature SAF production method. However, the limited availability of these feedstocks constrains the scalability of HEFA-based SAF.
More advanced SAF technologies, such as alcohol-to-jet (AtJ) and Fischer-Tropsch processes, offer greater flexibility in their feedstock inputs, including agricultural and forestry waste, municipal solid waste, and captured industrial CO2. These pathways, often referred to as “advanced biofuels” or “synthetic fuels,” hold immense potential to drastically scale up SAF production and contribute to aviation’s decarbonization.
Synthetic SAF produced from clean hydrogen and captured CO2, known as “e-fuels” or “power-to-liquid (PtL) fuels,” are a particularly promising solution. These e-SAF pathways can achieve greenhouse gas emissions reductions of over 90% compared to conventional jet fuel, while also offering improved local air quality benefits and the potential for on-site production. However, the high energy and capital requirements of current e-SAF technologies present significant challenges to their rapid scale-up.
Regulatory Frameworks and Policy Initiatives
To drive the widespread adoption of SAF, the European Union has taken several policy actions through its “Fit for 55” legislative package. The ReFuelEU Aviation regulation, for example, sets binding SAF blending mandates for aviation fuel suppliers operating at EU airports. These requirements will gradually increase the minimum share of SAF in fuel mixes, reaching 63% by 2050.
Complementing the regulatory push, the EU is also investing in research, development, and demonstration projects to advance SAF technologies and production capacity. The Horizon Europe program and the Innovation Fund under the EU Emissions Trading System provide significant financial support for SAF innovation and scale-up efforts.
Additionally, the EU is working to create a harmonized market for SAF through the development of common sustainability criteria and certification schemes. This approach aims to ensure that SAF deployed across Europe meet robust environmental and social standards, while also fostering a level playing field for industry players.
Environmental Impact Reduction
The widespread adoption of SAF is crucial for reducing the aviation sector’s carbon footprint and aligning it with Europe’s ambitious climate goals. SAF offer significant lifecycle greenhouse gas emissions reductions compared to conventional jet fuel, with some pathways achieving up to 80% or more in emissions savings.
Beyond CO2, SAF also have the potential to mitigate the non-CO2 climate impacts of aviation, such as the formation of persistent contrails and the release of other non-CO2 pollutants. By reducing these non-CO2 effects, which can account for more than half of aviation’s total climate impact, SAF can help the industry take a more comprehensive approach to decarbonization.
Promoting sustainable air travel through SAF deployment also benefits local air quality around airports, as SAF can reduce the emission of conventional pollutants like particulate matter and nitrogen oxides. This positive impact on public health and the environment is a crucial co-benefit of the transition to SAF.
Feedstock Diversification
The successful scale-up of SAF production will require the diversification of feedstock sources beyond the currently dominant used cooking oil and animal fat-based pathways. Exploring alternative biomass-derived feedstocks, such as agricultural and forestry residues, municipal solid waste, and industrial waste streams, can significantly expand the available pool of sustainable raw materials.
Likewise, the development of synthetic fuel pathways that utilize renewable hydrogen and captured carbon dioxide offers a promising avenue to overcome the limitations of bio-based feedstocks. E-fuels or power-to-liquid (PtL) fuels produced with clean electricity and green hydrogen can provide a scalable, low-emissions alternative to conventional jet fuel.
Investing in a diverse portfolio of SAF technologies and feedstocks is essential to ensuring a robust and resilient supply chain that can meet the growing demand for sustainable air travel in Europe and beyond.
Challenges and Barriers
Despite the clear environmental benefits of SAF, several challenges and barriers must be addressed to enable their widespread adoption. The economic feasibility of SAF production remains a significant hurdle, as current production costs are significantly higher than those of conventional jet fuel. Bridging this “green premium” will require further technological advancements, economies of scale, and targeted policy support.
The infrastructure requirements for the storage, blending, and distribution of SAF also represent a critical challenge. Integrating SAF into the existing aviation fuel supply chain will necessitate coordinated investments and collaborative efforts among fuel suppliers, airports, and airlines.
Raising public awareness and acceptance of SAF is another essential factor. Educating travelers on the environmental benefits of SAF and empowering them to make informed choices, such as through the use of flight emissions labels, can help drive demand and accelerate the transition to sustainable air travel.
As the European aviation sector embraces the challenge of decarbonization, sustainable aviation fuels emerge as a vital component of the solution. By leveraging technological advancements, supportive policy frameworks, and collaborative efforts across the value chain, Europe can unlock the full potential of SAF to reduce the carbon footprint of air travel and contribute to a more sustainable future. Visit the European Future Energy Forum to stay informed on Europe’s progress in this critical endeavor.