Decarbonising aviation: Challenges and solutions

Global aviation and its decarbonisation challenge

Before the COVID-19 pandemic, aviation contributed approximately 1 Gt CO2 annually, accounting for 12% of global transport emissions. Unmitigated, aviation could be responsible for 22% of global emissions by 2050. In 2019, global aviation was responsible for 1.2 Gt CO2e, necessitating a combination of decarbonisation measures to achieve net-zero emissions by 2050.

Decarbonisation solution portfolio

To decarbonise aviation, a combination of demand-side measures, efficiency improvements, and sustainable fuels is required. This includes transitioning to SAFs, developing novel propulsion aircraft, and implementing Carbon Dioxide Removal (CDR) solutions. Achieving this necessitates doubling historical fuel efficiency gains, rapidly scaling up SAFs, and introducing novel propulsion aircraft by the mid-2030s.

Achieving net zero: Possible trajectories

CO2-neutral growth until 2030, halving emissions by 2040, net zero by 2050

Two scenarios, Prudent (PRU) and Optimistic Renewable Electricity (ORE), outline paths to halve emissions by 2040 and achieve net zero by 2050. Achieving carbon-neutral growth by 2030 involves scaling SAF production and improving fuel efficiency. By 2040, renewable energy carriers must comprise 50% of the final energy demand.

Compatibility with 1.5°C carbon budget

Both scenarios are 1.5°C-compliant, staying within an 18 Gt CO2 carbon budget. The Business-as-Usual (BAU) scenario would exceed this budget by 117%, emitting 39 Gt CO2 by 2050.

Fuel efficiency improvements and SAF

For both net-zero scenarios, doubling fuel efficiency gains could avoid 14–16 Gt CO2e between 2022 and 2050, and SAFs could further reduce emissions by 16–17 Gt CO2e. SAF production must be scaled up by a factor of 5–6 by 2030.

Conclusion: From strategic thinking to action in this decade

Key milestones until 2030

Critical milestones include achieving carbon-neutral growth by 2030, halving emissions by 2040, and reaching net zero by 2050. The aviation sector must scale SAF production, introduce novel propulsion technologies, and implement CDR solutions to counterbalance residual emissions.

Policy, industry, and finance action to achieve 2030 milestones

Policymakers, industry leaders, and financial institutions must collaborate to set the course for 1.5°C and net zero. Early action is crucial to unlock technological innovations and economies of scale.

Recommendations

The report provides recommendations for industry, policymakers, and financial institutions. These include:

• Scaling up SAF production and developing hydrogen and battery-electric aircraft.
• Implementing advanced market commitments to boost SAF demand.
• Encouraging cross-value chain collaborations to de-risk new technologies.

Quantitative evidence suggests that by 2050, in-sector decarbonisation measures can reduce GHG emissions by 95% compared to 2019 levels. Achieving net zero will require substantial annual investments, estimated at $175 billion, primarily in renewable fuel production.

Technological potential of renewable fuels

Hydrogen and battery-electric aircraft could supply up to a third of final energy demand in 2050, with SAFs entering the market earlier and contributing significantly to GHG emissions reduction.

Resource demand and investments

By 2050, net-zero aviation could require 5,850 TWh of renewable electricity, 95 million tonnes of hydrogen, and 12 EJ of sustainable biomass annually. Average annual investments are estimated at $175 billion, with 92%–96% required for fuel production and upstream assets.

Key industry actions

• Doubling historical fuel efficiency gains.
• Rapid roll-out of SAFs and market entry of novel propulsion aircraft.
• Implementing advanced market commitments and scaling up SAF production capacity.

Key policy actions

• Establishing robust policy frameworks to support SAF production and adoption.
• Encouraging collaboration across the aviation value chain to achieve decarbonisation goals.

Key finance actions

• Mobilising investments to support the transition to net-zero aviation.
• Financing the development and deployment of new propulsion technologies and SAF production facilities.

Cost implications

SAFs are currently 2–5 times more expensive than fossil jet fuel, but efficiency gains could offset cost increases. By 2050, average fuel costs could rise by 90%–190%, with potential cost decreases per revenue passenger kilometre due to technology improvements.

CDR solutions
CDR is necessary to mitigate residual emissions, with investments needed immediately to sequester 120–140 Mt CO2e by 2050.

The way forward
The transition to net-zero aviation is feasible with coordinated efforts from all stakeholders. This includes significant investments in renewable fuels, technological innovations, and policy support to ensure a sustainable future for the aviation sector.