Aviation is committed to working together with governments and other stakeholders to address its climate impact. ATAG plays a key role in facilitating that collaboration. Haldane Dodd Executive Director, ATAG
In 2008, leaders from across the air transport industry gathered at ATAG’s Aviation & Environment Summit to sign the Commitment to Action on Climate Change. This was the initial stage in a process, guided by ATAG, which saw aviation become the first global transport industry to have a long-term plan to tackle its climate change impact.
In October 2021, the global aviation industry took its climate commitment one step further by declaring that it will achieve net-zero carbon emissions by 2050, supported by accelerated efficiency measures, energy transition and innovation across the aviation sector and in partnership with Governments around the world.
ATAG was instrumental in coordinating the declaration. The pathway to achieve net zero draws on analysis from the ATAG-led Waypoint 2050 project, which represented two years of collaboration among numerous aviation technical experts plus an additional ATAG study on the role of sustainable aviation fuels, entitled Fueling Net Zero.
Net zero carbon emissions by 2050 is significant as it supports the Paris Agreement goal to limit global warming to 1.5 degrees, compared to pre-industrial levels. Scientists agree that this would greatly reduce the severity of climate change damage.
Since the adoption of the goal in 2021, ATAG has worked extensively to garner support for net zero through individual meetings, speaking at conferences and government briefings and organising sessions on decarbonising aviation, including:
Achieving net zero carbon emissions by 2050 cannot be done by the aviation industry in isolation. Government support is one of the crucial elements. On 7 October 2022, governments meeting at the International Civil Aviation Organization (ICAO) Assembly in Montreal adopted a goal of net-zero carbon emissions for international flights by 2050. ATAG coordinated industry input and participated in discussions at the 41st ICAO Assembly.
This is one of the only global sector-specific climate goals and represents a milestone for the aviation sector. Air transport has always been able to work together to solve complex challenges and climate change is no different.
Many States will need help with implementing a net-zero pathway in their own country. Financing the transition will be a priority for governments, industry and the investment sector. The energy industry will need to get serious about the build-up of sustainable aviation fuels.
Net-zero aviation is a significant challenge, but it is fully achievable by working together across industry, governments, the energy sector and finance communities.
The net-zero goal is shaped in a way that allows for different speeds of decarbonisation by countries around the world, ensuring that each government can respond to its own national circumstances but within a common global framework of action. Everyone is flying in the same direction towards net-zero aviation by the middle of this century.
Aviation's strategy to minimise its climate change impact and fly net zero combines the following:
ATAG’s Waypoint 2050 report explores how the sector could achieve net-zero CO2 emissions by 2050, with the support of governments and the energy industry. Some regions and individual companies should be able to get to net-zero earlier than this.
The initial Waypoint 2050 work was conducted in 2019 and 2020 among 70 aviation sector experts, led by ATAG, to explore how a long-term climate goal could be reached. It analysed traffic forecasts and the role of technology, operations, infrastructure, sustainable aviation fuels and market-based measures.
In 2021, ATAG furthered the work of Waypoint 2050 and released an update to the report. This included the latest traffic and fleet data and an assessment of how the sector could achieve net-zero aviation by 2050.
The Waypoint 2050 report explored several potential scenarios for the decarbonisation of air transport:
Technology improvements are prioritised and ambitious with the expectation of the emergence of unconventional airframes and a transition of the fleet towards hybrid/electric aircraft in the short-range and up to 100-seat category, with entry into service from 2035/2040.
Significant investments in operations and infrastructure result in substantial improvements and CO2 reductions. The remaining gap to reach net zero is filled mainly with the use of sustainable aviation fuels: 90% of fuel is replaced with SAF with a 100% emissions reduction factor by 2050 (around 380 Mt of SAF).
This scenario identifies that 445 million tonnes of SAF would be needed by the sector in 2050. This SAF energy transition would require an investment of up to $1.45 trillion over 30 years. It would create opportunities for energy industries to develop in countries across the world and potentially sustain up to 14 million jobs in operations, logistics, feedstock supply and construction.
This places the emphasis on radical new technologies and energy sources such as electricity and hydrogen. Under this scenario, technology improvements are very ambitious with electric aircraft up to 100-seats, zero-emissions aircraft (powered by green hydrogen) for the 100-200 seat segment and hybrid-electric powered unconventional aircraft configuration for larger aircraft in the 2035-2040 timeframe.
For each of the scenarios, offsets (mainly in the form of carbon removals by 2050) will be needed to compensate for any remaining shortfall in emissions above the goal.
Waypoint 2050 also identifies the calls for action that will be needed to help reduce emissions in line with the various scenarios and the responsibilities of various stakeholders.
Full details are available from the Waypoint 2050 report.
IATA has developed an emissions calculator (see below) that enables passengers to easily calculate the CO2 footprint of their flights:
Information about the methodology, data used and how the CO2 emissions are calculated is available from IATA.
In addition to CO₂, aviation (like many other sectors) is responsible for other emissions that can have an impact on the climate.
Water vapour is also emitted as a byproduct of fuel combustion and under certain conditions, it can form condensation trails, or ‘contrails’. These familiar white lines in the sky are like human-made clouds and are the result of complex interactions between aircraft emissions and the atmosphere.
Some of these clouds only last for a few seconds, but if the air is humid and cold enough, they can persist for hours and spread across large sections of airspace.
Some contrails (particularly those occurring during the day) have a cooling effect by reducing the solar radiation reaching the Earth’s surface, much like naturally occurring clouds. Others (particularly those occurring at night) have a warming effect by trapping heat in the atmosphere, rather than allowing it to escape. The latest scientific consensus is that contrails have, on balance, a warming impact.
The aviation industry is actively contributing to scientific research, as well as participating in operational trials and other studies aimed at developing the means to reliably reduce persistent warming contrails. Studies so far have produced high numbers of false positives and false negatives in forecasting their formation. This makes establishing effective mitigation methods and estimating their impact very challenging.
ATAG has developed a briefing paper (in collaboration with industry experts) on the challenges and action underway to avoid persistent warming contrail formation.
Multiple efforts are underway to better understand the science behind the formation of contrails and to identify ways of avoiding their formation through the use of alternative fuels, revolutionary combustion technology and operational improvements.