Airline passenger numbers will be hit by the cost of decarbonising flights, the UK’s aviation industry has admitted.

Paying for measures such as making sustainable aviation fuel (Saf) widespread will put some people off travelling, according to a new report.

But the Net Zero Carbon Road Map published by Sustainable Aviation – an alliance including companies such as airlines, airports and manufacturers – insisted “people will still want to fly” despite “slightly” higher costs.

Aviation must prove it will decarbonise

Annual passenger numbers are still expected to grow by nearly 250 million by 2050.

The document stated that the use of Saf could make up at least three quarters of all aviation fuel for UK flights by that time, with the majority of it produced in the UK.

Saf is produced from sustainable sources such as agricultural waste and used cooking oil.

It reduces carbon emissions by up to 80% compared with traditional jet fuel, but is currently several times more expensive to produce.

Heathrow Airport’s director of sustainability Matthew Gorman – who chairs Sustainable Aviation, said new technologies such as Saf will have a “green premium before the market scales up and costs fall”.

He told the PA news agency: “There will be some additional costs for those, and that will have some impact on future demand.

“But we can still grow significantly and get to net zero, because what the evidence shows is in most cases people are happy to pay a bit more to travel.

“They value being able to travel, and in paying a bit more they’ll be investing in decarbonisation.”

The UK has an ambition for at least five commercial-scale Saf plants to be under construction by 2025.

The Government has invested money in the development of the sites, and proposed that airlines operating in the UK must ensure Saf makes up at least 10% of their fuel by 2030.

The Jet Zero Council – made up of industry, academic and government leaders – will meet at Farnborough Airport on Monday to devise a two-year plan to set out how the council will help accelerate the production of Saf by investing in plants, supporting scientific research and driving down production costs.

Transport Secretary Mark Harper will deliver the keynote speech at the Sustainable Skies World Summit, also being held at Farnborough Airport on Monday.

He will say: “This Government is a determined partner to the aviation industry – helping accelerate new technology and fuels, modernise their operations and work internationally to remove barriers to progress.

“Together, we can set aviation up for success, continue harnessing its huge social and economic benefits, and ensure it remains a core part of the UK’s sustainable economic future.”

At the moment, if you're an investor looking to invest in a Saf plant, you're going to go to the US rather than the UK

Sustainable Aviation fears “significant incentives” in the US and the rest of Europe designed to lure investors in Saf production are putting the UK at risk of missing out.

It wants the Government to introduce a mechanism which would reduce the difference in price between Saf and traditional jet fuel.

Mr Gorman said: “What the US has done is a whole series of tax incentives, which has pretty well closed the price gap with kerosene.

“At the moment, if you’re an investor looking to invest in a Saf plant, you’re going to go to the US rather than the UK.

“If we want to establish a leading position we need the right policies to get us there.”

He added: “This is the critical decade where aviation must prove it will decarbonise.

“Our updated Net Zero Carbon Road Map shows that we have a clear, credible path to take the carbon out of flying.

“Through a combination of Sustainable Aviation Fuel, more efficient aircraft and airspace, zero emission planes and carbon removals, we can protect the huge benefits of aviation for future generations without the carbon cost.”

On Monday, the RAF will operate its first flight with passengers onboard fuelled by a Saf blend to demonstrate its ability to use greener fuels once they become more widely available.

A Voyager aircraft will depart from its Brize Norton base in Oxfordshire and conduct an air-to-air refuelling sortie over the North Sea to provide a Saf blend to other RAF aircraft.

It will then fly past the Sustainable Skies World Summit – taking place at Farnborough Airport in Hampshire – before returning to Brize Norton.