Sustainable Aviation: The

Green sky THINKING

Airlines have set ambitious targets to reduce their carbon footprint but it won’t be an easy ride, says Gill Upton.

Have some sympathy for airlines

trying to decarbonise. While other industries are progressing more rapidly, aviation is hampered by multiple obstacles, thwarting the 2026, 2030, 2040 and finally net zero emissions goal of 2050.

Real progress has come in short-haul and regional air. Ravn Alaska has ordered 30 electric planes from developer ZeroAvia, Eviation Alice ran a test flight in September of its fully-electric aircraft, DHL has ordered 12 for its cargo operation and United has ordered 100 of the 19-seater regional electric aircraft Hart ES19. EasyJet is investing in a hydrogen-powered aircraft, alongside its partnership with Wright Electric for a 186-seater aircraft being tested in 2023.

Decarbonising short-haul flights will accelerate as batteries become more efficient over the next decade. Battery/electric and/or hydrogen/electric zero emission aircraft could replace most short-haul aircraft by 2050. Norway, for example, aims for all short-haul flights to be 100% electric by 2040.

But far less is happening to decarbonise long-haul flights. Airbus estimates its green hydrogen-powered planes (made from renewable electricity and partnered with Delta) will be available from 2035 – a long way off. To date there has been nothing publicly from rival Boeing.

“The manufacturers really need to get on with producing a decent-size, 200-seater zero-emission aircraft powered by hydrogen,” says Paul Le Blond, Chair of the Chartered Institute of Logistic and Transport’s Aviation Policy Group. “Churning out better fuelefficient aircraft with 20% savings is not good enough; it needs to be 100%.” 

 Le Blond derides where R&D money is going. “It’s a bit of a scattergun approach, with various pots of public money exploring different technologies, as we don’t know what’s going to work. It’s time now for focus. More change is needed and quickly,” he says.

Ideally, he would like to see co-ordinated government support and research into longhaul travel being achieved by smaller electric and/or hydrogen aircraft in a series of short hops rather than non-stop.

Unrealistic targets

Halving carbon emissions by 2030 – just over seven years away – probably won’t materialise. The UK Government’s Jet Zero Council has set a goal of delivering the world’s first zero emission long-haul flight by 2050 and awarded fiscal incentives for sustainable aviation fuels (SAF) to accelerate change. Meanwhile, Carbon Footprint has laid down the challenge of flying a zero carbon-emission (non SAF) 100-seater aircraft across the Atlantic in one hop to win the Freedom Fight Prize. ”It may accelerate change,” says Dr Wendy Buckley, Client Director. There are three contenders: Zero Avia, The ePlane Company and Okulo Aerospace.

The 2050 goal is not achievable using existing alternative fuels alone as this only hits a reduction of 36%.

Bob Schumacher, Director Sales at United Airlines, says a strategy using “multiple levers” is needed, and most airlines are following this path. Virgin Atlantic, for example, is a founding member of the Aviation Climate Taskforce (ACT), Jet Zero Council and Sustainable Aviation and part of the Clean Skies for Tomorrow initiative, which bring together industry, government and technology experts to “tackle this global problem as a coalition of the willing”, says a spokesperson.

Moreover, SAF is too expensive due to insufficient capacity (and concerns over displacing land to grow it) so some airlines are engaging with corporates to purchase more in order to reduce the price.

United’s Eco Skies Alliance has grown from 12 signees, including Deloitte, Nike and Siemens, to nearly 20. The Delta/Air France KLM/Virgin Atlantic corporate SAF programme has 40, including Google and Chevron.

SAF is also scarce as only 55 airports provide it, a fraction of the world’s 15,000plus major airports. “There is currently only enough SAF available on the market to support one day of Delta’s operations at prepandemic levels,” says Clare Black, GM Home Markets at Delta.

American Airlines is one of many lobbying for a combination of private and public funds to scale SAF production. John Nicholls, Global Head of ESG and Sustainability at Corporate Travel Management (CTM), is calling for “a policy change and budgetary inclusions for governments to co-support the SAF initiative”.

Virgin Atlantic is supporting efforts to build the UK's first SAF plant by 2025. But detractors say being over-reliant on SAF and planting trees will never remove the 660 billion tonnes of carbon dioxide needed to limit global warming.

Flight paths

Modernising fleet to include more fuelefficient aircraft is hampered by delivery backlogs. Switching to electric for ground vehicles is an immediate win and Delta, for example, is electrifying 50% of ground service equipment by 2025. Another quick fix is greening the supply chain.

Offsetting is part of most airlines’ plans and is supported by IATA, which refers to offsetting as a “key immediate enabler” via the International Civil Aviation Organisation’s (ICAO) Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), which aims to “stabilise international emissions at 2019 levels in the short- to medium-term”.

IATA reckons that by 2050 65% of carbon mitigation will come from SAF, 13% from new propulsion technology such as hydrogen, 3% from efficiency improvements, 11% from carbon capture and 8% from offsets.

IATA has lobbied for subsidies to drive technological change. Being able to fly in straight lines to save fuel would help too, as would removing older aircraft and regulating for a higher percentage of SAF fuel blend.

Despite these multiple levers, the Travel Smart Campaign says current targets will not keep to the Paris Agreement goal for global warming not to exceed 1.5 degrees C.

“SAF takes 80% out of the fuel so there is still 20% left, so we need to do the technology and pull the carbon out. SAF is a bridge. We need to look at what else we can burn,” says United’s Schumacher.

Emerging technologies

Green hydrogen is one possibility – although doubters point to capacity and storage issues – and carbon capture another.

Air Company is creating a new SAF fuel made from captured carbon dioxide. Direct air capture technologies (DAC) can pull vast quantities of CO2 from the atmosphere while using very little land and water but it is still in its infancy. United has invested in one DAC developer, Carbon Engineering.

Airlines with deeper pockets are doing the most and, as a non-competitive area, are

willing to share best practice.

Lufthansa is investing in power-to-liquid technology that uses renewably-generated electricity, water and CO2 to create a synthetic crude oil that can be processed into kerosene. Tim Johnson, Director of the Aviation Environment Federation, reckons this is the more promising technology than fuel from waste, which IAG is investing in despite a myriad of practical issues.

Ultimately, he believes the only solution is a curb on growth. "But this is something this government is not willing to entertain," he says. "Constraint of the industry has to be part of the package, to grow cautiously in accordance with our ability to decarbonise.”

A modal shift must follow and Chris Truss, International Development & Sustainability Director at Reed & Mackay, recognises this as the more difficult part.

"It’s a tough call if the traveller is a gold card holder,” he says. But Truss believes sustainability is a more credible and reputational argument than predilections.

It's a bit of a scattergun approach, with various pots of public money exploring di erent technologies as we don't know what's going to work"

Shared frustrations

Travel managers are embracing sustainability (it will impact their share price otherwise) by prioritising rail over air and road, striving to travel smarter and more purposefully and supporting the SAF roll-out, but they too face obstacles.

These are highlighted by Carol Fergus, Global Travel Director at Fidelity, which shares top slots with Novo Nordisk, Swiss Re Group and Legal & General Group in the Travel Smart Campaign rankings. She says her key frustrations are non-standardised data and insufficient comparative data on airlines’ carbon reduction initiatives.

“We’re unable to choose one airline over another as the data is very crude. It’s a minefield to ensure that we’re working with the most sustainable airlines as all the airlines are doing different things, so we cannot compare like with like," she says. "Switching airlines is challenging due to scheduling and issues over traveller preferences. Our policy is cheapest on the day but emissions come with a price tag so we have to look at all the variables.”

Fergus would like simplified carbon measurement and methodology and a joined-up approach between industry and government for a universal standard without such a high price tag.

“Without a common standard across the industry it is very hard to measure progress, benchmark or set realistic goals,” agrees Jens Liltorp Manager, Global Travel and Meetings, LEO Pharma in Denmark.

Sally Higgs, Travel & Events Sustainability Manager at Festive Road, adds: “I think corporates are paralysed on action as they don't have the tools, budget and support to effectively reduce their emissions.”

Reed & Mackay hopes to release a sustainability module by Christmas, giving real-time carbon footprints of individual flights at point of sale. CTM reckons its Lightning OBT already provides that data at time of booking, showing differences between cabin class emissions on the same flight and highlighting the proportionate impact of travelling in premium cabins.

Moreover, airlines must disclose more, says Truss, although judging by the pushback from airlines (particularly those with a high percentage of premium passengers) on the ICCT carbon emission rankings on transatlantic flights, this is unlikely to happen. Low-cost carriers fare better.

There is still much to do for the aviation industry to get its house properly in order but, encouragingly, the days of flight shaming are long past.