The aviation industry contributes to global connectivity and economic development (Fig. 1), but its environmental impact poses a formidable challenge in the context of urgent climate action. Yet, decarbonizing aviation is challenging. Aircraft rely on energy-dense liquid hydrocarbons and emit nitrogen oxides and condensation trails, which influence radiative forcing1,2. In 2019, carbon dioxide emissions from global aviation reached more than a gigaton of carbon3. With demand for aviation projected to double or triple by 2050 compared to the 2019 level4, it is crucial to achieve sustainable aviation, while meeting the growing demand for passenger and cargo transport if we are to mitigate the environmental footprint. The transition to sustainable aviation is not merely a technological challenge. It is a systemic transformation that requires coordinated efforts from airlines, air traffic management authorities, aircraft manufacturers, and environmental organizations.

Fig. 1: Global flight trajectories in 2024.
figure 1

Density and distribution of global air traffic highlight aviation hubs, flight corridors, and areas of concentrated activity.

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We propose six pathways to decarbonize aviation that integrate near-term solutions and long-term innovations. The pathways include the adoption of sustainable aviation fuels, advancement of hydrogen and electric propulsion, optimization of air traffic management, and implementation of policies that incentivize sustainable practices.

Six pathways

Adopt sustainable aviation fuels

Sustainable aviation fuels represent the most viable near-term pathway for decarbonizing aviation. Produced from renewable feedstocks such as waste oils, municipal solid waste, agricultural residues, and algae, they can mitigate up to 80% of carbon dioxide emissions in lifecycle compared to conventional aviation fuels5. Key production technologies include Hydroprocessed Esters and Fatty Acids, Fischer-Tropsch, Alcohol-to-Jet, and Power-to-Liquid, which convert diverse feedstocks into energy-dense fuels tailored for aviation.

Sustainable aviation fuels are typically blended with conventional ones (up to 50%), ensuring compatibility with existing aircraft engines and fueling infrastructure. Advances in feedstock optimization through biotechnology, renewable energy integration in conversion processes, and cost-effective supply chain development are essential to scaling the deployment of sustainable aviation fuels, reducing production costs, and meeting the growing global demand for sustainable aviation solutions.

Develop zero-emission technologies

Achieving zero-emission aviation requires a holistic approach, integrating advancements in propulsion systems, aircraft design, and materials. Hydrogen-powered aircraft, emitting only water vapor, represents a transformative solution for long-term decarbonization, relying on advancements in fuel cell technologies and cryogenic storage systems6. Electric propulsion provides a complementary pathway for short-haul and regional flights, reliant on breakthroughs in battery energy density and power-to-weight ratios.

Hybrid-electric systems represent a critical transitional step as they reduce fuel burn in conventional engines while advancing electric technologies. Moreover, novel aircraft designs, such as blended-wing bodies and laminar flow technologies, improve aerodynamic efficiency. Lightweight materials, such as advanced composites and metallic alloys, enhance the overall performance7.

Improve efficiency of flight operations

The optimization of flight operations, airspace management, and ground activities is a practical pathway for reducing fuel consumption and emissions8. The adoption of continuous descent operations and performance-based navigation can allow smoother and more direct flight paths9. The use of dynamic air traffic flow management can help minimize delays and holding patterns. The reduction of aircraft weight through improved loading practices can also contribute to reducing their environmental footprint.

On the ground, single-engine taxiing, electrification of ground support equipment, and minimization of the use of auxiliary power units further enhance fuel efficiency. Additionally, the use of real-time data analytics for predictive maintenance and fuel optimization can significantly contribute to sustainable operations.

Implement policies that incentivize sustainable practices to achieve net zero emissions

Driving aviation sustainability requires a robust policy framework based on carbon pricing and stringent criteria10. The International Civil Aviation Organization targets net-zero emissions for global aviation by 2050, supported by the Carbon Offsetting and Reduction Scheme for International Aviation.

The European Union aims for a 55% reduction in aviation emissions by 2030 and net-zero by 2050, leveraging sustainable aviation fuels and emission trading systems. The United States similarly targets net-zero by 2050 through initiatives like the Sustainable Aviation Fuel Grand Challenge. China plans to peak aviation emissions before achieving carbon neutrality by 2060, focusing on green airports and sustainable aviation fuels. Japan and the United Kingdom also target net-zero by 2050, with strategies emphasizing sustainable aviation fuels, hydrogen-powered aircraft, and optimized air traffic management. These efforts highlight global actions for promoting sustainable aviation.

Promote alternative transports

Leisure and social air travel are the largest and fastest-growing contributors to long-distance emissions11. In particular, private aviation is increasingly contributing to climate change, with direct emissions reaching at least 15.6 megatons of carbon dioxide in 202312. Airport operations electrification, renewable energy investment for ground services, and urban air mobility integration—for example, electric vertical takeoff and landing vehicles—are emerging areas that complement broader aviation sustainability goals.

Integrate digital technologies

The integration of digital technologies, particularly artificial intelligence and digital twins, offers an opportunity to optimize operational processes across aviation systems, from aircraft operations to air traffic management. These technologies can improve fuel consumption efficiency and reduce emissions through enhanced predictive analytics and real-time operational decision-making. Furthermore, the incorporation of renewable energy sources and the principles of circular economy in airport infrastructure design and operations can play a pivotal role in reducing aviation’s broader environmental footprint.

Challenges

Significant technological, economic, and regulatory challenges hamper the development of sustainable aviation. High costs of sustainable aviation fuels, often far exceeding those of conventional aviation fuels13, hinder widespread adoption, particularly for airlines operating under tight profit margins. This economic pressure drives reliance on carbon offsets rather than investment in greener technologies. Technological advancements, including biofuels, synthetic fuels, and hydrogen-powered aircraft, remain in the early stages, requiring substantial research, investment, and supportive infrastructure.

Operational inefficiencies, such as outdated air traffic systems and the environmental impact of airport infrastructure, further complicate efforts. While initiatives like the Next Generation Air Transportation System from the United States Federal Aviation Administration aim to modernize operations, global coordination is essential to ensure consistency. Regulatory inconsistencies also exacerbate challenges. In Europe and North America, policy frameworks include enforceable mandates, financial incentives, and industry-driven commitments that actively drive sustainable aviation fuel adoption. In contrast, many Asia-Pacific countries primarily rely on direct government subsidies or state-led initiatives without extensive market-based mechanisms or regulatory mandates14. China is expected to be the world’s largest civil aviation market in the long term, with the highest passenger and cargo volumes, and scale of aviation infrastructure15. This positions China as a critical player in the global transition towards sustainable aviation. Overcoming these barriers demands a unified global approach that integrates technological innovation, infrastructure investment, and coherent regulatory frameworks.

Way forward

Realizing the full potential of cleaner propulsion technologies demands continued advancements in their scalability, efficiency, and economic feasibility, alongside substantial investment. Simultaneously, breakthroughs in materials science, such as lightweight composites and advanced alloys, and innovations in aerodynamics, including blended-wing body designs and laminar flow technologies, are essential for improving fuel efficiency and further reducing emissions. The convergence of these fields is vital for creating aviation systems that are not only efficient but also environmentally responsible.

The path to decarbonizing aviation presents significant technological and economic hurdles. However, through the alignment of scientific research, technological innovation, and policy efforts, the aviation sector can play a leading role in mitigating climate change. By fostering the development of cleaner propulsion systems, advanced materials, and digital solutions, aviation can contribute to a more sustainable and environmentally integrated transportation system, ensuring a cleaner and carbon-neutral future.