Sustainable Aviation Fuel: Greenwashing or Real?

Every time you book a flight today, you likely see a small leaf icon or a prompt to “offset your carbon footprint.” Airlines are under immense pressure to reduce their environmental impact. The aviation industry currently accounts for about 2.5% of global CO2 emissions. To combat this, the industry is betting its future on Sustainable Aviation Fuel, or SAF. But with marketing campaigns ramping up faster than fuel production, travelers are right to ask: Is this a genuine solution, or just sophisticated marketing?

What Exactly is Sustainable Aviation Fuel?

Before determining if it is a scam, it is important to understand what it is physically. SAF is not a single product. It is an umbrella term for alternative jet fuels made from non-petroleum sources.

Unlike hydrogen or electric propulsion, SAF is a “drop-in” fuel. This means it has chemical properties almost identical to conventional Jet A-1 fuel. It can be mixed with regular jet fuel and burned in existing aircraft engines without any mechanical modifications.

Currently, the most common type of SAF is HEFA (Hydroprocessed Esters and Fatty Acids). This is produced primarily from:

  • Used cooking oil (fryer grease)
  • Animal fats
  • Waste oils

Advanced versions under development aim to use agricultural waste, municipal trash, or even “e-fuels” created by capturing carbon from the air and mixing it with green hydrogen.

The headline statistic you will see on airline websites is that SAF reduces carbon emissions by up to 80% over the fuel’s lifecycle. It is not zero-emission at the tailpipe, but because the carbon emitted was previously absorbed by the plants used to make the oil, the net addition of carbon to the atmosphere is significantly lower than pulling new oil out of the ground.

The Reality Check: Current Usage and Availability

Here is where the greenwashing concerns often begin. While the technology is real, the scale is currently microscopic.

According to the International Air Transport Association (IATA), SAF production in 2024 represents roughly 0.53% of total aviation fuel requirements. That is less than one percent.

When an airline claims to be “flying green,” they are usually flying on a blend that is 99% fossil fuel and 1% SAF, or they are buying credits for SAF used elsewhere.

The Cost Barrier

The biggest hurdle is price. SAF currently costs between two and five times more than conventional kerosene. Airlines operate on razor-thin profit margins. Without government intervention or massive scale, purchasing large quantities of SAF is economically impossible for most carriers.

Specific Airline Commitments

Despite the low volume, several major players are making verifiable moves:

  • United Airlines: They launched the Eco-Skies Alliance. In 2023, United used more SAF than any other US airline, though it still represented a tiny fraction of their total fuel burn.
  • Virgin Atlantic: In November 2023, Virgin operated “Flight 100” from London Heathrow to New York JFK. This was the first commercial aircraft to fly across the Atlantic using 100% SAF. While it carried no paying passengers (only scientists, media, and officials), it proved the safety and viability of the fuel.
  • KLM: The Dutch airline has been a pioneer but also faced legal trouble. In 2024, a Dutch court ruled that KLM’s “Fly Responsibly” campaign was misleading because it gave customers an overly optimistic view of the sustainability of flying.

The "Book and Claim" System

If you pay extra for a “green fare” or an offset at checkout, you might assume your specific plane will use biofuel. That is almost never the case.

The industry uses a “Book and Claim” model. It works like this:

  1. You fly from Denver to Chicago and pay a surcharge for SAF.
  2. Your plane in Denver is fueled with standard 100% fossil jet fuel because the airport may not have a SAF supply.
  3. The airline purchases the equivalent amount of SAF you paid for and inserts it into the fuel supply at a hub that does have it, such as Los Angeles International (LAX) or Amsterdam Schiphol.

This system is necessary because shipping SAF to every airport would create more emissions than it saves. However, critics argue this disconnect makes it easy for airlines to obscure exactly how much green fuel they are actually buying versus how much they are just talking about.

Is It Greenwashing?

The answer is complex. The technology is real, but the marketing often outpaces the reality.

The Case for Greenwashing:

  • Misleading Ads: Regulators are cracking down. In 2023, the UK’s Advertising Standards Authority (ASA) banned ads from Lufthansa and Air France-KLM, stating that they gave a false impression of the environmental impact of flying.
  • Feedstock Limits: There is not enough used cooking oil in the world to power global aviation. If the industry scales up using palm oil or crops grown specifically for fuel, it could lead to deforestation, which negates the environmental benefits.

The Case for Reality:

  • Government Mandates: This is not just corporate goodwill. The European Union has passed the ReFuelEU Aviation initiative. This mandates that fuel suppliers at EU airports must blend 2% SAF by 2025, rising to 6% by 2030 and 70% by 2050.
  • US Tax Credits: The Inflation Reduction Act (IRA) in the United States provides tax credits ranging from $1.25 to $1.75 per gallon for SAF producers. This financial backing suggests a tangible shift in infrastructure is coming.

The Future: Beyond Cooking Oil

For SAF to be more than a niche experiment, the industry must move beyond cooking oil. The real “holy grail” is Power-to-Liquid (PtL) or e-fuels.

This involves using massive amounts of renewable electricity to separate hydrogen from water, then combining it with carbon captured from the atmosphere or industrial smokestacks. The result is a synthetic fuel that is theoretically near carbon-neutral.

Currently, e-fuels are produced in pilot plants and are incredibly expensive. However, brands like Neste (the world’s leading producer of renewable diesel and jet fuel) are investing billions into expanding refineries in Singapore and Rotterdam to accommodate various raw materials.

Conclusion

Sustainable Aviation Fuel is not a hoax, but it is also not a magic wand that fixes the climate impact of your vacation today.

When you see an airline boasting about green initiatives, look for the details. Are they talking about a single demonstration flight, or a committed percentage of their annual fuel buy? Currently, SAF is a verified technology suffering from a massive supply shortage. It is the most viable path to decarbonizing long-haul flights, but we are decades away from it being the industry standard.

Frequently Asked Questions

Is flying with SAF safe? Yes. SAF goes through rigorous testing to meet ASTM International standards. It is chemically almost identical to standard jet fuel. Thousands of flights have used it without a single safety incident related to the fuel.

Does SAF make flight tickets more expensive? Likely, yes. Because SAF costs significantly more to produce than fossil fuel, airlines will pass these costs to passengers. In Europe, where mandates are kicking in, you may see “environmental surcharges” added to ticket prices in the coming years.

Can I choose to fly on a plane using SAF? Not directly. Because of the “Book and Claim” system, you cannot select a specific flight based on fuel type. However, flying through major hubs like LAX, SFO, or Amsterdam increases the likelihood that some SAF is in the airport’s general fuel mix.

How much carbon does SAF actually save? SAF reduces carbon emissions by roughly 80% over its lifecycle compared to jet fuel. It is not 100% because energy is still required to collect the waste, refine it, and transport it to the airport.