The aviation sector is a hard-to-abate industry for decarbonisation and will remain essential for the global economy. Today it contributes around 2-2.5% of global carbon emissions, but as other industries progress their decarbonisation journey, the proportion of aviation’s contribution to global emissions is likely to increase.
Why is aviation so hard to abate? With today’s technology, aircraft propulsion is highly dependent on kerosene, with both hydrogen and electric technologies yet to be proven commercially viable.
According to the International Air Transport Association (IATA), the average commercial aircraft flying in September 2024 is 11.6 years, with many airlines operating aircraft over 20 years old. Therefore, aircraft purchased with today’s technology will still operate in the 2040s.
So what’s the solution? The IATA Fly Net Zero strategy identifies that 13% of the solution will come from emerging technologies and just 3% from infrastructure and operational efficiency improvements, while the majority (65%) coming from adopting Sustainable Aviation Fuel (SAF). The remaining 19% is planned to come from offsets and carbon capture.
SAF, a biofuel with properties nearly identical to conventional jet fuel, offers a much lower carbon footprint. Derived from renewable resources such as used cooking oil and waste animal fats, SAF can reduce greenhouse gas (GHG) emissions by up to 80% over its lifecycle, depending on the feedstock and production process.
Countries are increasingly incorporating SAF into their Net Zero strategies. The UK’s Jet Zero strategy targets 10% SAF use by 2030, aiming for net-zero aviation by 2050. Europe’s ReFuelEU initiative mandates 2% SAF by 2025, 6% by 2030, and 70% by 2050. It would appear that the adoption of SAF, along with an increase in regulatory requirements, could bridge the gap until emerging technologies provide a long-term solution.
However, there are questions about SAFs scalability and commercial viability. In 2019, the commercial aviation sector (excluding military and private jet use) consumed 96 billion gallons of aviation fossil fuel. In 2023, the global production of SAF was 158 million gallons, less than 0.2% of 2019’s jet fuel requirement. The US aims to produce 3 billion gallons of SAF annually by 2030.
There will be a global shortfall in the medium term and a price differential that will ensure the kerosene has the cost advantage. This is evident in limited adoption by airlines.
In recent years, Delta Airlines used SAF for less than 1% of its fuel, and Southwest Airlines used SAF for just 2%, while Boeing purchased 5.6 million gallons which makes up 25% of their total jet fuel needs, although this also includes blended SAF fuel (SAF and jet fuel mix). However, detailed reports on emissions reductions by SAF grades are lacking, highlighting a gap in granular data analysis.
SAF is an integral part of the solution, as are the emerging technologies, hydrogen, electric and carbon capture, but their impact will be limited in the short and medium term. Aviation is a hard-to-abate industry, but waiting for technology to emerge and SAF production to increase would be a mistake.
As consumers become increasingly informed about environmental issues, they demand greater company accountability and honesty. It is the role of the aviation industry to level expectations and individual airlines must adopt a more rigorous and transparent approach to address these issues.
They should provide precise, verifiable data on SAF usage and its impact on emissions. By adhering to established standards provide a structured and transparent way to account for and verify SAF usage. Any claims must be accurate and credible.
Moreover, airlines that communicate openly and accurately about their sustainability efforts will avoid legal pitfalls and build stronger relationships with environmentally conscious consumers, some of whom see carbon-offsetting as ‘greenwashing’. Transparency and rigorous reporting are crucial to maintaining trust and staying ahead of potential challenges. Looking ahead, in this evolving landscape, the future of aviation hinges on levelling expectations now, not tomorrow.
Aviation is essential to the global economy, but travel will not be guilt-free for the short and medium term. If the benefits of travel are to continue to be enjoyed, the industry needs to change expectations and individual airlines need to accurately measure and communicate their contribution.
To that end, sustain:able – a consultancy focused on industry, technology and helping clients transition – and strategic consultancy Herdwick Communications recently announced a partnership offering an integrated approach for robust technical reporting and effective communications.
This article was co-written by Dr Rachel Gavey, Co-Founder sustain:able, Sustainability Consultant Nikhil Patel and Mike Evans, Co-Founder, Herdwick Communications
