As a report claims that airlines are struggling to control their contribution to the climate crisis, the question grows more urgent for aviation: does it have a greener future, and will a zero-emission plane ever fly?

Executives hope a combination of sustainable fuels, offsetting and improving flight paths can play a part in reducing aviation’s footprint until, if ever, carbon-free flying becomes a viable technological and commercial reality. For now, the best long-term hope for the airline industry appears to be electric planes.

At Cranfield University, the laboratory for much of British aviation research, the transport secretary, Grant Shapps, on Thursday urged the industry “to create an electric revolution in our skies”; for the climate and, incidentally, “to seize a share of a market that could be worth £4tn globally by 2050”.

Manufacturers are pursuing electric dreams: not just companies like Boeing and Airbus, but a host of tech firms, particularly for urban air mobility – aircraft that could be clean and silent enough to make shorter air hops possible without large airports. How much that can be scaled up remains a question. For now, the development of batteries with better power-to-weight ratio means shorter trips on small planes may not be far away.

At this year’s Paris air show, electric planes on display included a nine-seater plane named Alice, being developed just outside Tel Aviv by Eviation. The Israeli startup is aiming to have commercial deliveries of its plane as early as 2022.

A bigger version, a partly British-built hybrid electric plane, is aiming for test flights in 2021. The e-Fan X, a collaboration between Cranfield with Airbus, Siemens and Rolls-Royce, will convert a small passenger jet to demonstrate the potential for wider commercial use.

That kind of project has excited analysts: the move towards hybrid and electric engines for short-haul flights could come in the next two decades, according to an analyst report by UBS.

Another zero-emission alternative could be hydrogen, the fuel behind a plane soon to be tested on flights from the Orkney islands. Trials backed by £5.3m in government funding were announced this week – underlining the potential of hydrogen for commercial aviation, according to Val Miftakhov, the founder and chief executive of ZeroAvia, which is providing the plane’s propulsion technology. He said: “Our project goal of 300 nautical miles is equivalent to the distance from London to Edinburgh and will prove that zero emission aviation, powered by hydrogen, can play a key role within the UK and other countries’ transport strategies - enabling net-zero targets to be met.”

The cost of producing and storing hydrogen is one major barrier. But Dr Bobby Sethi, a senior researcher at Cranfield, believes the current cost of liquid hydrogen – five to six times that of jet fuel by weight – will come down. Sethi said: “As large scale hydrogen production and liquefaction infrastructures become more established, and that of jet fuel and taxation of CO2 emissions goes up, particularly with heightened environmental awareness, we believe LH2 (liquid hydrogen) will be very competitive on cost in the medium to long term.”

Manufacturers like Airbus predict new forms of plane will come – but not for 15 years. Bob Lange, a senior vice-president, says hybrid-electric propulsion could be feasible by the mid 2030s. The newest planes unveiled in recent years, such as Airbus’s A350 and Boeing’s 787, have brought a step-change in fuel efficiency, but Lange says the next major product launches will be on hold. “We need to do our research and development now for the next fuel technology.”

Before those planes appear, the industry – and the planet – needs other ways to curb aviation emissions. Sustainable fuels were a major hope for aviation; and with concerns over biofuels, the focus has shifted to the potential of domestic and industrial waste. A Virgin service claiming to be the first to be partly powered by recycled waste crossed the Atlantic last October. According to its US fuel supply firm, LanzaTech, if that single flight could be scaled up – and more importantly, function with a fuel blend of 50% recycled waste rather than just 5% – it could curb greenhouse gas emissions by 65% compared with conventional jet fuel.

British Airways has eyed similar technology and – after several false starts – has submitted plans to develop, with Shell, a new plant in Immingham, Humberside, which could divert half a million tonnes per year of waste – from packaging to nappies – into more sustainable jet fuel.

Other measures have been stalled in planning: a single European sky and better air traffic management could cut CO2 emissions by 10%, the industry says.

Airlines are meanwhile fighting to avoid more punitive taxation, with Germany poised to announce additional levies on flying. A4E, a trade body representing Lufthansa, BA and others says: “Instead of taxes, the German government should support measures such as reforming EU airspace.”

But as aviation finally gets moving on emissions, the pace of change may prove too slow to avoid a clampdown.