Sustainable Aviation Fuel (SAF)

The airline industry has been focusing on Sustainable Aviation Fuel (SAF) as a cornerstone for decarbonising air travel. The International Air Transport Association (IATA) suggests that SAF could account for 65% of the industry’s path to reduced carbon emissions. The appeal of SAF lies in its compatibility with existing aircraft and infrastructure, which avoids the need for a major technological overhaul. However, while SAF offers significant benefits, it also presents certain challenges that must be addressed as part of a broader strategy for achieving environmental sustainability in aviation.

Emissions Comparable to Conventional Jet Fuel

SAF, like conventional jet fuel or kerosene, is a hydrocarbon fuel and emits as much CO2 as kerosene when burned in aircraft engines. The production of SAF captures carbon through its bio-based feedstocks, such as plants or agricultural waste, theoretically offsetting emissions. However, this offsetting does not equate to a fundamental reduction in emission levels from flying. Despite this, the lifecycle emissions of SAF can be significantly lower than those of fossil fuels, particularly when advanced production methods and sustainable feedstocks are used.

Challenges with Scalability and Costs

The production of SAF faces scalability issues due to the growing demands of the aviation industry. Research from Bain & Company projects that by 2050, SAF will only meet about 20% of global aviation fuel demand, highlighting a significant supply gap. Furthermore, the cost of SAF is more than double that of conventional jet fuel, compounded by expensive raw materials and complex production processes that hinder scale economies. Despite these challenges, continued advancements in technology and increased investment could potentially lower costs and improve scalability over time.

Environmental and Energy Overheads

The widespread adoption of SAF could lead to significant environmental trade-offs, such as indirect land-use changes that may affect food production and biodiversity. The Royal Society, for example, warns that replacing the UK’s current jet fuel consumption with SAF derived from biofuels could consume up to half of the nation’s agricultural land. Additionally, the energy required for SAF production could demand a significant increase in renewable energy capacity. Careful consideration and sustainable practices are essential to mitigate these potential impacts.

The Way Forward

While SAF contributes to offsetting aviation emissions, it encounters substantial hurdles concerning direct emission reduction, scalability, cost, and overall sustainability. Therefore, it should be considered as part of a broader, multifaceted strategy to decarbonise the aviation sector. In addition to SAF, airline decarbonisation will likely require a combination of programmes, including operational efficiencies, improved air traffic management, modernisation of older fleets with new more fuel-efficient aircraft and engines that are more fuel efficient, and offsetting residual emissions through carbon capture and storage (CCS) or reforestation projects. Investments in newer technologies such as electric or hydrogen-powered flight will also play a crucial role in achieving the aviation industry's sustainability goals.  In addition, the industry needs to all participants to pull together. One of the biggest issues to-date has been one of co-ordination. No one player can solve the problem of emissions on their own. What is needed is a coordinated effort across the sector.

Conclusion

Only by adopting a holistic, co-ordinated approach can the aviation sector make significant strides toward a greener future. As the sector anticipates significant growth, with projections indicating a 28% increase in the global commercial fleet by 2034, it is imperative that airlines in collaboration with aircraft and engine manufacturers, urgently explore hybrid and co-ordinated strategies for decarbonisation. There is no magic single solution. The projected increase in aviation's share of global greenhouse gas emissions—from 3.4% today to an estimated 22% by 2050—underscores the need for comprehensive and scalable solutions beyond what SAF alone can offer. By integrating SAF into a wider decarbonisation strategy, the aviation industry can better navigate the complex path toward a sustainable future.