Like most middle-aged men, I'm a small boy at heart. I like cars and ships and trains and even aircraft, provided I don't have to fly in them. So I was genuinely excited on 28th November 2023 when Virgin Atlantic flew a commercial airliner from London to New York using only sustainable aviation fuel (SAF). Numerous Advertising Standards Authority (ASA) adjudications have upheld complaints against various airlines for using references to SAF to burnish their green credentials, when in truth it only accounts for a small proportion of their fuel usage. But this flight demonstrated that a conventional airliner could cross the Atlantic propelled exclusively by SAF in potentially the biggest technological breakthrough in transatlantic flight since Alcock and Brown first traversed the ocean in their modified Vickers Vimy bomber in 1919. And this time, neither pilot nor navigator had to shin out onto the wings of the aircraft to knock the ice off the wings, in what apparently passed for in-flight entertainment in those early days of long-haul air travel. 

A modern technological breakthrough

In December 2022, Virgin Atlantic announced that they had won a competition run by the UK’s Department for Transport to “support industry to achieve the first net zero transatlantic flight on an aircraft using 100% sustainable aviation fuel within one year”. The aim was to study the “technical and operational feasibility of using 100% sustainable aviation fuel in a commercial passenger aircraft”. Currently, SAF can only be used in a blend with conventional fossil fuel of up to 50%, although in practice, the blend is usually only 10% to 30% SAF.

Virgin’s radio commercial

A few days before the historic flight, Virgin Atlantic hit the air waves with a radio ad that declared, “On the 28th of November, Virgin Atlantic’s Flight 100 will take to the skies on our unique flight mission from London Heathrow to JFK to become the world’s first commercial airline to fly transatlantic on 100% sustainable aviation fuel. When they said it was too difficult, we said: challenge accepted. Virgin Atlantic Flight 100. See the world differently.”

The meaning of the claim is as clear as the view from an aircraft at 30,000 feet. The aircraft was fuelled with SAF and nothing but SAF. And yet five people complained to the ASA that the claim “100% sustainable aviation fuel gave a misleading impression of the fuel’s environmental impact.”  The ASA upheld their complaints in an adjudication published on 7th August.

What is Sustainable Aircraft Fuel?

The term “Sustainable Aviation Fuel” is an industry defined, standard term. It is used by governments, regulators and all the interested parties around the world. It describes synthetic aviation fuel that is not derived from fossil fuel. There are also recognised sustainability criteria that apply, and it is certified by independent certification entities using established methodologies to calculate the lifecycle greenhouse gas savings. 

If you want to satisfy your inner nerd, there is considerable detail in the adjudication about SAF, and the particular type used in Virgin Flight 100. In essence, the flight used used fuel comprised of about 88% Synthetic Paraffinic Kerosene “made using waste oils and lipids from animal fats” which are deemed unfit for human consumption, and 12% Synthesised Aromatic Kerosene derived from dextrose, which is a new product under development.

What was the environmental impact of using SAF on this flight?

According to Virgin Atlantic, “Overall, Flight 100 had delivered a lifecycle CO2 emissions saving of 64%” and “around 40% lower non-CO2 emissions (particulates such as water, sulphur oxides, soot and nitrous oxides) compared to fossil derived fuels.” 

So is SAF 100% sustainable? No. 

Was the fuel used on this flight 100% SAF rather than the usual blend of 10-30% or even the legal maximum blend of 50%? Yes.

Did the SAF used on this flight substantially reduce both CO2 and non-CO" emissions? Yes.

How would the ‘Average Consumer’ interpret the ad?

The complainants alleged that the radio ad implied that SAF is 100% sustainable, rather than that the flight was fuelled only by SAF. But is that how the Average Consumer is likely to interpret the claim? Or is it a strained interpretation used by people who think all green claims are greenwashing? Or by people who would like to ban all advertising by airlines? Or even by people who would just like to ban all advertising? 

Back in the days of Alcock and Brown, when the courts had to consider the likely reaction of the so-called ‘reasonable man’, they would evoke the notion of ‘the man on the Clapham omnibus.’ Presumably an environmentally friendly, horse-drawn omnibus. These days, Clapham bus man has been superseded by the gender-neutral ‘Average Consumer’ who is ‘reasonably well-informed and reasonably observant and circumspect’. 

Virgin Atlantic argued that in this context, the Average Consumer would understand “100% sustainable aviation fuel” to refer to a fuel made from sustainable sources, “which reduced but did not necessarily completely eliminate greenhouse gases.” To support this argument, Virgin Atlantic conducted a survey which found that 68% of respondents understood that SAF was ‘significantly’ or ‘somewhat’ better for the environment than traditional jet fuel. Given that the flight had delivered a lifecycle CO2 emissions saving of 64% and around 40% lower non-CO2 emissions, that seems like a reasonable conclusion. And if that was the finding of about 7 out of 10 respondents, that seems to reflect the likely interpretation of the Average Consumer.

What did the ASA decide and why?

Unfortunately, the ASA decided to focus on the other 32% of respondents to the survey. Of these, 21% thought that SAF had a similar or worse impact than traditional jet fuel, but only 11% thought that it had zero environmental impact. This means that only about 1 in 10 respondents were potentially misled in the way envisaged by the complainants. However, about 30% of respondents also replied that it was true that SAF has “zero impact on the environment”.  The ASA therefore decided to uphold the complaint.

The problem is that the ASA focussed on “the significant minorities of respondents who did not have an accurate understanding of the environmental impact of sustainable aviation fuel after listening to the ad.”  As every first-year law student used to know, the opposite of ‘the man on the Clapham Omnibus’ is ‘the moron in a hurry’. But what they think is irrelevant. The question which the ASA should be answering is what did the Average Consumer take from the ad? Instead, the ASA upheld the complaint on the basis that “a significant proportion of listeners were likely to overestimate its environmental benefits”. That may be a true of a significant minority of listeners (representing the people of limited intellect in a rush), but if the Average Consumer is not likely to overestimate its environmental benefits, then the complaint should not have been held.

Greenhushing or Greenwashing?

In an interesting ASA Opinion piece published on 23rd June 2023, the ASA rejected the argument that there is a binary choice between greenwashing or greenhushing. They refer to adjudications against airlines were rightly upheld. Etihad, for example, claimed to be taking “a louder, bolder approach to sustainable aviation”, which turned out to be a lot of hot air.

The adjudication against Virgin concludes that “We acknowledged the ad specifically highlighted Flight 100, which was a non-commercial flight for which listeners could not purchase tickets. However, it had the effect of building the overall impression that Virgin Atlantic was committed to taking on a challenging, pioneering and continuing role in working towards reducing the environmental impact of aviation. The ad specifically highlighted the use of sustainable aviation fuel in Flight 100; a method by which a reduction in environmental impact could be achieved. We therefore considered that information about its limitations in that regard constituted material information that would have an impact on the transactional decisions of those listeners.”

It is probably true that Virgin Atlantic were hoping for a ‘halo effect’ on their reputation because of Flight 100. Any why not? One day, when Sustainable Aviation Fuel is available at scale and its environmental performance has been enhanced, we may look back on Flight 100 and consider it to be a ground-breaking as Alcock and Brown’s first transatlantic flight in 1919.

In the meantime, if we are going to encourage innovation to promote a greener future, we need to recognise that when assessing whether a green claim is greenwashing, we need to do so by reference to the Average Consumer, not by reference to those who are uninformed, oblivious and inattentive. Otherwise, we risk greenhushing stifling green innovation.