From contrails to e-fuels, how a UK-led coalition is helping plot a flightpath to greener aviation

Speed is of the essence. The world has a very short space of time to decarbonise and, while there’s no shortage of innovation, promising technologies have yet to scale. How do policymakers decide which levers to pull to incentivise innovation and investment, while avoiding the sort of unintended consequences that accompanied an early push for biofuels? And how can they be encouraged to move swiftly? Aviation is a good example of the challenge. The industry is responsible for more than 2% of global carbon dioxide emissions, but once non-CO2 emissions are considered the figure could be at least twice as high. No one knows what its decarbonised future will look like. Sustainable aviation fuel (SAF), hydrogen or battery electric could all play a role, but how much will depend on factors such as the speed of grid decarbonisation, competition for feedstock from other sectors (for example, shipping) and new battery chemistries. In 2020 Professor Rob Miller, director of the Whittle Laboratory at the University of Cambridge, was involved in a series of aviation workshops organised by the then Prince of Wales, through his Sustainable Markets Initiative. All the relevant players were in the room, from technology experts to air traffic controllers and airport operators. “What we realised in those meetings was that people were talking past each other; there was no common language,” says Miller. The field of aviation had “become very siloed … nobody saw the whole picture anymore.”<br/>