Sustainable Aviation Fuel Is Promising But Not A Panacea

It’s THE big hope of the aviation sector to fight climate change. Recently, airlines have been communicating around, and investing massively in, sustainable aviation fuels.

At the 2021 United Nations Climate Change Conference, the newly launched International Aviation Climate Ambition Coalition included “the development and deployment” of SAF in their list of action points. The coalition is counting on SAF to make the biggest impact in their quest for net-zero emissions by 2050, but the reality is that SAF is not a panacea that will cure all of the industry’s sustainability woes.

The aviation sector has failed to keep its promises so far. In 2008, the International Air Transport Association aimed for using 10 percent SAF by 2017. Four years later, usage amounts to 0.1 percent. Can we trust current forecasts?

It is a good sign that airlines are investing in research and development and exploring the possibilities of SAF, but it will never be able to solve the problem on its own. Instead, it should be a part of a more holistic, aggressive strategy to mitigate the negative environmental effects of air travel.

A Real Take-Off

Let’s start with the good news. The fact that airlines are so invested in this topic shows that climate change is now at the top of their agenda, while it was clearly not a major concern for many just a few years ago.

From an engineering perspective, today’s aircraft engines can use up to 50 percent SAF without any major improvement to the current technology. Some recent innovations may even allow for 100 percent SAF usage in the near future. Furthermore, unlike the automotive industry, the airline industry tends to follow the right path and uses mostly (although not exclusively) waste and residue to produce SAF.

Last but not least, SAF is not only biofuel—a fuel made from organic material—but also refers to e-fuels (or synthetic fuels). There have been some recent technological breakthroughs in this area. Atmosfair, a German-based company, recently managed to produce synthetic kerosene from carbon dioxide and hydrogen using power from wind turbines—a renewable and clean energy.

…But Physics Rules Are Merciless

Here’s something that may surprise you: When SAF is burned in the atmosphere, it releases exactly the same quantity of CO2 as fossil kerosene. However, when considering its full lifecycle, it ends up being closer 50 percent to 80 percent less CO2 overall, because the raw materials used to create the fuel have themselves absorbed CO2 during their lifecycle. Unfortunately, that doesn’t mean that SAF does not pollute the atmosphere at all. Think about it this way: Today’s aircraft can use 50 percent SAF, and that SAF reduces the CO2 emissions by 80 percent at the very most. However, the non-carbon related effects of flying (radiative forcing) are at least equal to the carbon emissions, so SAF doesn’t even solve 25 percent of the problem.

When it comes to biofuels, according to some scientists, we would need to use the entire world’s food production to create enough fuel to meet the pre-Covid aviation industry’s needs. Obviously, we can’t use the whole world’s food supply to create fuel, but even if we use waste to produce SAF, it is not a scalable solution. The growing pressure to produce SAF presents a problem to farmers who use land for food production. In the United States, the lack of stringent regulations increases the risk that some agricultural production will go to SAF. Although there are stricter rules in Europe, danger still looms. French oil and gas giant TotalEnergies recently planned to use palm oil in its French production facility but abandoned the plan due to strong objections from environmental groups.

Synthetic fuels are the more promising solution since the production does not compete with local agriculture. However, they do have one major weakness: the quantity of energy required for the production is enormous, and that energy must be low carbon (renewable or nuclear). The airline sector would need roughly three or four times the current renewable energy infrastructure existing in the world today to produce enough synthetic fuel to meet the industry’s needs.

Will SAF Be Legitimate In An Energy-Constrained World?

Energy experts throughout the world have been warning us about the energy crisis for years, but many governments and media haven’t taken it seriously. “The world may be sleepwalking into a supply crunch, albeit beyond 2021,” wrote Simon Flowers, chief analyst of Wood Mackenzie, a research and consulting firm that specializes in oil and energy, in 2020.

We very well may be at the dawn of major energy turmoil. And we might have already entered it in the summer of 2021. Could the continuous increase of prices at the pumps and the boom of gas tariffs be a preview of what will happen in the coming years? “We have entered turbulence,” said Shift Project director Matthieu Auzanneau, who shows in his book, Oil, Power, and War that oil has shaped our societies and economies in a way that is highly underestimated today. He explains that the oil shortage to come (peak oil is behind us, according to the experts), which, although potentially good news for the climate, will result in massive societal upheavals that we cannot anticipate today.

What will SAF’s role be in this bleak future? In other words, considering the likely (but not certain) scenario where energy becomes scarce and prices rise massively, will society and governments be willing to use a precious resource to feed aircraft engines while households struggle to pay for heating? Will authorities insist that we use SAF for more urgent needs, like household electricity production? It is hard to imagine that SAF will be used for aviation if energy does become scarce and increasingly expensive.

There is no question that SAF is a useful tool for combating climate change, assuming it’s produced with 100 percent waste or renewable energy. That’s where the airline sector’s investments and R&D should be focused. Because in the dark (but likely) scenario of an energy-constrained world, we will need SAF for a variety of applications, even if the primary use isn’t for air travel. However, betting on SAF to decarbonize the airline sector in the near future is a risky one—and it’s likely a bet that will be lost.