As the world’s first sustainable aviation fuel (SAF)-based flight by Virgin Atlantic takes off, climate experts and world leaders are preparing to board kerosene-based flights to gather for the COP28 climate summit in one of the world’s largest producers of oil – the United Arab Emirates.
At the same time, the UN reports that the world faces between 2.5°C to 2.9°C of warming above pre-industrial levels if governments do not boost climate action. In June 2023, the global temperature temporarily passed the 1.5 Paris Agreement threshold, and the IPCC estimates that, under a moderate emissions scenario, the world is likely to surpass 1.5°C in 2030. Exceeding 1.5°C risks resulting in runaway climate change.
UK government claims ‘a new era of guilt-free flying’
With the aviation sector being one of the most difficult sectors to decarbonize, shouldn’t we applaud the success of both Virgin Atlantic, and Rolls-Royce for getting their Trent 1000 engines to run smoothly on a fuel that can save up to 70 per cent of CO2 emissions?
The Department for Transport (DfT) certainly approves, saying the flight was ‘ushering in a new era of guilt-free flying’. This is unsurprising given DfT’s Jet Zero Strategy central scenario relies heavily on SAFs, delivering around 20 per cent of emissions reduction in 2050, and even more in the ‘breakthrough of SAFs’ scenario.
Is scaling up supply realistic in time to prevent dangerous climate change?
But let’s step back. Most countries, including the UK have set 2050 targets for delivering net zero. To supply the fuel the world will need to not only produce the bioenergy feedstocks used to create SAFs, but also finance and build enough facilities capable of processing the bioenergy feedstocks into useable SAFs.
The UK’s recently announced world’s largest waste-to-jet fuel facility will provide 165 million litres of SAF. The Dutch developer of the Teeside facility claims this will be enough to meet 10 per cent of the UK 2030 SAF target.
But given climate change is a global challenge, and people from all countries fly, it is the global perspective that matters here. The Sustainable Fuels UK Road-Map report indicates that if the global aviation sector were to rely on SAFs to the same scale as the UK, at least 140 million tonnes of SAFs per year would be required by 2050.
In 2020, global production of SAFs was around 0.1 million tonnes/year, meaning that by 2050 supply would need to increase 1,400-fold. Or perhaps more tangibly, around 1,000 facilities of equivalent size to that planned in Teeside. To put this in context, there are around 825 active oil refiners in the world.
The message here can be simplified. We are running out of time to tackle climate change. Globally we have acted far too slowly, and supply-side decarbonization takes decades to scale up.
Land tensions, food insecurity and suspected fraud
All bioenergy-based technologies are land intensive, as was recently discussed in this Chatham House report. To meet the UK government’s Jet Zero Strategy central scenario SAF production target, between 13–22 per cent of all UK agricultural land would need to be turned over to growing bioenergy crops, assuming 100 per cent miscanthus feedstock (a type of grass grown as a bioenergy crop), and based on the methodology of the Royal Society.
Losing this amount of food production-dedicated land will have significant impacts on food prices, and could result in food insecurity for the world’s poorest people.
Given SAFs require so much land, it is no wonder that there are growing concerns that current SAF production from ‘used cooking oil’, is not quite what it seems. UK government data indicates that more than 80 per cent of SAF supplied to airlines last year was made from imported ‘used cooking oil’.
Malaysia supplied 7 million litres, China supplied 5 million, and Indonesia 1 million. Under the UK’s Renewable Transport Fuel Obligation , waste products earn double credits. However, there are growing suspicions that the recent surge in exports from China involved fraudulent declarations.
Vasu R. Vasuthewan of the International Sustainability & Carbon Certification said, ‘When the demand is exponential in such a way, I’m afraid there will be the problem of not only can we supply, but also the incentive for all kinds of fraud in the supply chain’.
But even if fraudulent declarations are eradicated and genuine used cooking oil were to be used, the land pressure is likely to remain. According to Transport & Environment, a clean transport campaign group, even genuine used cooking oil can result in deforestation, as countries export oil they would otherwise have used and instead use palm oil to meet domestic demand.
What is the bigger picture solution for the aviation sector?
As shown in the recent Chatham House research paper, not only are SAFs behind schedule and scaling them up embodies risk, but all the potential decarbonization options for the sector suffer the timescale conundrum and/or externalities at scale.
Chatham House research has shown that cutting the number of flights and distances flown in the near term in parallel with pursuing technological solutions would be less risky and prevent the need for more drastic measures to reduce demand in the future. UK demand in terms of passenger-kilometres flown in 2030 would need to be 36 per cent lower than in 2019, with demand returning to 2019 levels by 2050, once
In the UK the top fifth of earners fly five times more often than the poorest fifth. Encouraging people who currently take more than one return flight per year to reduce that number by one return flight, and