LONDON, Nov 26 (Reuters) - The expansion of green jet

fuels could suffer a significant set-back under president-elect

Donald Trump, according to aviation officials, who fear the

reversal of tax credits needed to kick-start the sector.

The comments by members of airlines trade body IATA and

American Airlines ( AAL ) at an airlines industry conference in

London are among the first assessments of what a Trump

presidency could mean for nascent clean jet fuels.

"There are these big potential risks on what the Trump

policy is actually going to be and how this really affects

everybody's motivation to pursue climate change," Marie Owens

Thomsen, chief economist for airlines trade body IATA, told

Reuters.

The 2022 U.S. Inflation Reduction Act contains hundreds of

billions of dollars in subsidies for clean energy and is billed

as outgoing President Joe Biden's signature law to combat

climate change.

Europe's airlines sector, which will have to meet a new

mandate for use of sustainable aviation fuels starting in 2026,

has repeatedly pointed to the IRA as a useful model to encourage

investment into the construction of new SAF production plants.

President-elect Donald Trump, a climate skeptic, has vowed

to rescind it, something that would require the support of

Congress.

While existing SAF production facilities are likely to

continue producing the fuel, government affairs experts at

airlines have said, any rollback of the IRA could put the future

of new projects at risk.

As it stands, sustainable aviation fuel makes up only around

1% of the world's jet fuel usage, with experts saying the

production rate of the green fuel needs to grow quickly for the

sector to achieve a goal of net zero carbon emissions by 2050.

Trump's incoming administration could have the opposite

effect.

"The market needs certainty in terms of building up their

reservoir," said Ronce Almond, American Airlines' ( AAL ) head of

intergovernmental affairs, during the airlines industry

conference in London on Monday.