European plane makers Airbus have set an arrival date for hydrogen-powered planes, promising a clean plane engine by the middle of the decade.
The partnership with engine makers CFM International promises to deliver an engine with zero-emissions by 2035. Tests are due to get off the ground within the next three years.
Running off hydrogen, the only exhaust fumes would be water vapour.
The first test engine will be mounted on an Airbus A380, in addition to its four turbofans in a test to measure the performance of the hydrogen powered planes.
It's an experiment that Airbus and CFM want to see done by the middle of the decade.
Airbus chief technology officer Sabine Klauke calls it the most significant step the company has taken since announcing the first concepts in 2020.
"By leveraging the expertise of American and European engine manufacturers to make progress on hydrogen combustion technology, this international partnership sends a clear message that our industry is committed to making zero-emission flight a reality," said Klauke.
Aviation currently represents a large chunk of greenhouse gas emissions, an effect that is made worse by burning fossil fuels at high altitude. According to journal Atmospheric Environment the warming effect of jet emissions could be double that of actual emissions, representing just under 4 per cent of warming.
While Airbus experiments with hydrogen-fuelled aircraft, airlines like Air New Zealand have been looking at synthetic biofuels and alternative power to cut down emissions.
Last October IATA said that use of sustainable fossil fuels could cut down flying's footprint by as much as 65 per cent.
Hydrogen could represent another piece in the puzzle of the goal of achieving 'Net Zero' emissions, as set out by IATA in October last year.
The French government committed €1.5 billion ( $2.5 billion) towards the development of hydrogen-powered aviation, in 2020. This grant started the journey of Toulouse-based Airbus to developing the new technology, which could be working as soon as 2025.
Prototypes for hydrogen-powered aircraft range from reverse engineering traditional turbofan jet engines and propeller planes to run on liquid hydrogen to space-aged looking blended-wing body planes.
The blended-wing planes could give Airbus more options for hydrogen storage and distribution on the aircraft. Hydrogen has higher energy by weight than jet fuel, but it has lower energy by volume, meaning aerospace engineers will have to get creative with fuel storage.