Decarbonising global aviation is feasible but will be a significant challenge, finds major industry report

The main focus of this year’s Global Sustainable Aviation Forum, organised by the cross-industry Air Transport Action Group (ATAG), was the publication of Waypoint 2050, an analysis of pathways towards the sector’s long-term climate goal. Set over a decade ago, the target calls for a 50% net reduction in CO2 emissions by 2050 from what they were in 2005. This would mean a reduction from around 914 million tonnes (Mt) in global commercial airline carbon emissions in 2019 to 325 Mt in 2050. At the global level, the industry does not foresee reaching net-zero emissions before 2060/2065 although recognises a number of airlines will reach this by 2050, in response to national or regional goals. Given current traffic forecasts, which have been downgraded due to Covid-19, emissions could rise to 1,800 Mt by 2050 on a business-as-usual trajectory and reaching the reduction target will be a significant challenge, says ATAG, with the next 10 years being a crucial period.

“We should be under no illusion that the decarbonisation path for aviation is an easy one,” ATAG’s Executive Director, Michael Gill, told the virtual conference. “But our Waypoint 2050 analysis shows that decarbonisation is possible, and in a number of different ways. We now need the commitment from governments, the energy industry, researchers and from the aviation sector itself to make it happen.”

In its ‘Vision for 2050’, the Waypoint report expects the aviation sector to be transporting around 10 billion passengers a year, more than twice 2019 levels but 16% less than previous forecasts due to the impact of the Covid-19 pandemic. This represents a compound annual growth rate of 3% from 2019 to 2050. Much of the growth will take place in Asia-Pacific, the Middle East, Africa and Latin America, although significant growth will remain in North America and Europe. The industry sees three possible limits to growth: environmental concerns from consumers, governments moving to reduce growth, or a shift to other modes of transport, such as rail. However, it expects these to have limited impact. Covid-19 will have a major impact though on the sector’s carbon emissions in the short term and IATA expects this year they will be around 60% lower than in 2019.

New energy sources in 2050 will enable electric and hybrid-electric aircraft – with virtually no CO2 emissions at all – on short- and medium-haul routes, connecting secondary cities and small communities with larger hubs for onward long-haul flights. Most long-haul operations will use aircraft a generation beyond those that are flying today, with nearly all completely powered by sustainable aviation fuel (SAF) from a variety of sources, including power-to-liquid (PtL) fuels that are made by combining low-carbon electricity with CO2 removed from the air.

Although aircraft technology innovations and improvements in operations and infrastructure will continue to bring fuel and carbon reductions, the Waypoint report says the single largest opportunity to meet and go beyond the industry’s 2050 goal is the rapid and worldwide scaling up of SAF and new energy sources. A nearly complete shift to SAF, with a requirement of up to 450-500 million tonnes, will be needed, it says. This is achievable without impacting food or water use through using a range of available feedstocks, from non-food crops to waste sources and eventually a shift to PtL fuels and hydrogen. However, it will require support from government and the energy sector, with policies to ensure feedstocks are channelled towards aviation and not to other transport sectors where alternative energy sources are available.

The report explores three consolidated scenarios for how air transport can meet its long-term goal. Which of these scenarios plays out over time will likely be determined by how investment is prioritised in both SAF deployment and radical new aircraft technologies; whether energy providers can massively scale up SAF and hydrogen production at the same time; and if governments, finance institutions and consumers play the required role to accelerate the energy transition. There is a good case for current fossil fuel consumption subsidies around the world – worth $4.4 trillion over the last decade – to be re-directed towards low-carbon energy, it argues.

“For sustainable aviation fuel in particular, we need support from governments in the next decade to help set the stage for the future of low carbon connectivity,” said Gill. “These new fuels are already flying today – over 270,000 commercial flights have taken off so far – but are still a tiny part of our overall fuel mix. We know that we can begin the energy transition away from fossil fuels in earnest, but we need support to do so.”

Reaching the 2050 goal comes with a significant price tag for the sector, points out the report.

“If airlines are investing in new aircraft, they may have less ability to also invest heavily in SAF scale-up. Likewise, some significant decisions need to be made: does it make more sense to have a singular focus on traditional liquid SAF or wait a decade for electric or hydrogen aircraft to be available,” it questions.

“The reality is the sector will need to investigate all options and pursue those that make the most sense, but there is unlikely to be bandwidth, financing or resources to push all levers at once.”

The report acknowledges that in the event the contribution from technology, operations and infrastructure improvements, plus emissions reduction from SAF, are not sufficient to meet the 2050 goal, there could be a need for the industry to compensate remaining emissions through offsetting beyond the intended ending of ICAO’s global carbon offsetting scheme CORSIA in 2035.

Sources of offsets could change significantly in the future, it says, and as well as forestry and natural climate solutions, technologies such as carbon capture and storage (CCS) and direct air carbon capture and sequestration (DACCS) could form the basis for viable offsets. However, it warns there is likely to be a large amount of residual CO2 emissions still being generated across the economy in 2050 and beyond, and there could be competition to secure remaining offsets, which could result in scarcity and high prices.

The report argues the aviation sector’s 2050 goal to halve net CO2 emissions on a 2005 baseline is compatible with the Paris Agreement goal to limit global temperature rise to “well below 2 degrees C above pre-industrial levels”. To meet a 1.5 degree C goal will require a peaking of emissions across the economy between 2020 and 2030 and a rapid reduction in emissions towards net-zero emissions by mid-century.

“For hard-to-decarbonise sectors such as air transport, meeting the 1.5 degree C goal and keeping a small percentage of overall human emissions will be a major challenge,” it says. “For aviation to play a role in helping to achieve the 1.5 degree C pathway, it is likely that global aviation would need to reach net-zero emissions in the middle years of the century (2050 to 2070). This is in line with the projected post-2050 situation outlined in this report, finding that aviation could reach net-zero emissions by 2060/65, but assumes all other sectors also make aggressive cuts in CO2 emissions in line with their technical ability to do so.

“Governments are now taking action and setting ambitious climate targets. It is recognised that some regions may be able to transition their aviation industry to net-zero carbon emissions earlier than others.”

The industry report calls on all governments to set a long-term CO2 goal for international aviation at ICAO’s next Assembly in 2022 that was compatible with the most recent scientific evidence from the UN’s Intergovernmental Panel on Climate Change.

In an address to the ATAG conference, ICAO Council President Salvatore Sciacchitano said the Covid-19 crisis provided an opportunity to build back the commercial aviation sector greener and more sustainably, including its role in the social and climate impacts of international travel and tourism. He welcomed the recent announcement of the commitment by the oneworld airline alliance to reach net-zero emissions by 2050, adding green aviation innovations would feed into ICAO’s exploration of the feasibility for a long-term goal.