Making air travel greener could depend on nuclear reactors being installed around Australia's coastline and trillions of dollars in investment, according to an aviation industry heavyweight.
Emirates president Sir Tim Clark sounded the warning on his first trip to Australia in two years, just days before the company was due to launch a new test of more environmentally friendly fuel.
But the airline veteran said engine technology had started to emerge that could help the industry cut its emissions, alongside advances that could make passengers' airport experiences more seamless.
Airlines around the world, including Qantas, Virgin and Emirates, have committed to making air travel carbon neutral by 2050, in line with Paris Agreement targets.
But Sir Tim said it was still unclear how the companies would achieve this goal as sustainable aviation fuel had not delivered "dramatic" emission reductions and was not being produced at a scale to support the entire market.
"I honestly believe that if we are going to find an alternative source of fuel it has to be based on green hydrogen and synthetic fuels," he said.
"Modular nuclear reactors around the coastlines of Australia or the United Kingdom would give you the power to drive the processes that allow you to extract green hydrogen.
"Everybody says great idea but don't put one near me. The coastline of Australia is large and it is not well populated. Perfect."
Sir Tim admitted the suggestion may not be well received by environmental groups but said the industry ultimately had to find a way to cut fuel emissions to avoid catastrophic environmental outcomes.
Earlier this week, Emirates ran ground tests using 100 per cent sustainable aviation fuel on a Boeing-777 engine, and a test flight is due within days.
The fuel, which is already being used on some flights, uses waste such as cooking oil, fats, crops and agricultural residues.
Additional fossil fuel cuts could come from new plane designs that were starting to emerge, he said, including Rolls Royce's UltraFan engines that went into testing in December.
Other advances in air travel could hit airports within the next five years, Sir Tim said, with biometric technology eventually used to scan passengers' faces, check their profiles, and let them avoid traditional security scans.
"Right the way through to the boarding gate, there'll be no paper, there'll be no central search -- bags, handbags, everything out -- because the machines themselves will look at what you're carrying," he said.
"And they'll know you because (artificial intelligence) will store you and (know) you don't regularly travel with half a tonne of cocaine in your handbag."
The Emirates chief, who has presided over the company since 2003, also predicted the price of air travel could start to return to pre-pandemic levels, along with the number of flights, but only when inflation figures stabilised around the world.
The author travelled to Melbourne as a guest of Emirates.
