Sustainable Aviation Fuels not a ‘silver bullet’ to clean up aviation industry, suggests study
Sustainable Aviation Fuels – largely considered to be one of the key solutions to decarbonising fossil fuels from the aviation industry – might not be as effective at reducing emissions as previously thought.
As a polluter and contributor to climate change, the aviation industry is desperate to find sustainable alternatives to liquid fossil fuel, which it is currently dependant on.
Sustainable Aviation Fuels (SAF) – which can be biofuels produced from crops and agricultural waste or synthetic fuels made using renewable energy and carbon captured from the air – are believed to offer a solution.
In fact, it’s said SAF can reduce CO2 emissions produced by aircrafts, by up to 80%.
But new research from Manchester Metropolitan University and collaborators, published in Science of the Total Environment, suggests that SAF might not be a ‘silver bullet’ to decarbonising the industry.
In fact, their analysis has found that in order to produce enough SAF to decarbonise aviation by 2050, large amounts of biomass will be needed, as well as a large amounts of renewable energy.
When you consider the amount of biomass – so that’s the sustainable materials and waste – needed to fuel aviation in this way, it’s a huge amount, and for what is a relatively small industry
Scientists say this will have significant implications to not only other industries, but also put pressure on the availability of land to grow biomass, and the availability of clean energy.
Another implication to the use of SAF is the amount of time it takes to grow biomass. It can take decades to regrow forestry-type crops and replace the carbon from those crops that has been used as fuel.
David Lee, Professor of Atmospheric Science at Manchester Metropolitan, said: “SAF is considered to be the way forward when it comes to decarbonising aviation – somewhat of a silver bullet even.
“But there are many implications to the use of SAF and the reliance on it to make flying environmentally friendly.
“When you consider the amount of biomass – so that’s the sustainable materials and waste – needed to fuel aviation in this way, it’s a huge amount, and for what is a relatively small industry. This needs to be considered.
“Although renewables are becoming more and more readily available – which is fantastic to see – the demand on clean energy by 2050 is going to be huge, and there is going to be a lot of competition for it, and that’s something that our findings show needs to be accounted for too.”
The study shows that in order to create enough SAF to decarbonise the aviation industry by 2050, around 30% of available biomass, globally, will be needed.
As manufacturing SAF requires large amounts of energy to produce, it will also use around 9% of all available renewable energy.
This is because production of SAF from biomass and organic material, relies on renewables to turn crops into fuel in a sustainable way.
For the study, scientists analysed 12 ‘roadmaps’ for decarbonising the aviation industry, published by a variety of national and international trade bodies and associations – all of which relied on the use of SAF in their plans.
Plans depend on the notion that SAF reduces carbon emissions by up to 80%, however researchers found that up to 50% of these fuels cannot achieve this.
These findings were similar to those of a recent Royal Society Report, which Professor Lee also contributed to, that addressed the challenges of reducing the climate impact of aviation.
Research also showed that some SAF are made using carbon captured from the atmosphere. This means that vital infrastructure with the ability to take carbon – which could be used to help combat the climate crisis – would need to be used to create fuel instead.
