Aviation environmental groups have criticised the government’s sustainable aviation fuel (SAF) mandate, details of which were confirmed today, saying it does not go far enough.
The mandate will require increasing amounts of alternative fuels to be blended with kerosene from next year, but the Aviation Environment Federation (AEF) said: “Making jet fuel from waste won’t solve aviation’s emissions problem.”
It noted that while SAFs are produced from sources other than fossil fuel, they release just as much CO₂ as oil-derived jet fuel (kerosene) once burned in an aircraft engine.
Any emissions reductions overall depend on the feedstock for the fuel.
AEF policy director Cait Hewitt said: “Ministers and the aviation industry like to make out that alternative fuels will be the big solution for tackling aviation emissions. But the truth is these fuels will be in limited supply and most will be produced using wastes.
“That doesn’t reduce CO₂ – it just takes carbon, like plastic bottles in a rubbish dump, and puts it back in the atmosphere. It’s not even sustainable.”
Hewitt argued: “If this mandate means the government finally acknowledging the aviation emissions problem can’t be solved without policy action, then perhaps it’s a step in the right direction.
“But what we really need is a reduction in aviation emissions. A percentage mandate for alternative fuel in an industry hungry for growth can’t guarantee that.”
She suggested: “For the time being, the best way to cut emissions from flying is to fly less.”
Matt Finch, UK Policy Manager at Transport & Environment, described the SAF mandate as “woefully unambitious”, saying: “Despite the name, not all SAFs are genuinely sustainable, and with this mandate the Government has decided to put airline profits above the planet by allowing in huge quantities of dubious SAF.
“There are already huge problems with the waste oils we convert into biodiesel for cars, and the government has inexplicably ignored those by allowing such huge quantities to go into planes.”
He suggested: “This effectively guarantees the government’s stated aim of having five SAF plants under construction in 2025 won’t happen.
Finch also criticised the government’s suggestion that it was leading the world with its 10% target for SAF use by 2030, saying: “The EU is taking aviation decarbonisation far more seriously than the UK.
“The EU will require 34% of jet fuel to be sustainable in 2040, compared to just 22% in the UK. The EU has also recognised the important role hydrogen will play by requiring 10% green hydrogen-derived fuel in 2040, compared to 3.5% here.
“It’s clear who the climate leaders are. Our government has its head in the clouds.”
The government also published a consultation on a ‘revenue certainty mechanism’, aimed to assure investors on the level of returns from producing alternative fuels in the UK.
Hewitt said: “On the revenue certainty mechanism, the important thing is that it’s airlines not the public which pay for any fuels or technologies designed to cut emissions.
“With no tax on aircraft fuel and no effective emissions charges for flights outside Europe, it’s about time we made the polluters pay.”
The Green Alliance, a London-based environmental think tank, also weighed in on the SAF mandate, noting: “Aviation has a unique net zero challenge [and] simply boosting sustainable aviation fuels won’t fix it.”
It noted the Committee on Climate Change, which advises the government, points out UK aviation emissions have risen 88% above 1990 levels due to increased numbers of flights and passengers.
The alliance said SAFs “will play a role” in decarbonising aviation “but can’t be the sole technology we depend on”.
It pointed out: “The sustainability credentials of SAFs range widely depending on their source. Waste-based biofuels, from plastics or used oils, are highly polluting and incentivise production of unsustainable source materials.
“The only carbon neutral SAF is a ‘power to liquid’ or e-fuel derived from green hydrogen and carbon captured from the air.”
The alliance called for “limiting airport expansion, at least until there are zero emission solutions”.
Johann Beckford, Green Alliance senior policy adviser, suggested reducing aviation’s carbon emissions will need “a lot of bets on new technologies to pay off”.
He said: “It’s good to see the government take steps to phase out fossil fuel flying – and there is a small but welcome nudge towards the cleanest ‘power to liquid’ fuels in its new plan.
“But some replacements for kerosene aren’t sustainable – backing biofuels, for example, is a mistake when they’re highly polluting and can’t be produced at the scale we need.”
Beckford argued: “Transport remains the highest emitting part of the UK economy and, given sustainable aviation fuels are just one part of the solution, it’s smart to take other steps towards reducing emissions now, like closing the tax loophole on jet fuel.”