Cleaner Aviation Demands Disruptive Investment in Breakthrough Tech

(UNITED STATES) A group of energy and aviation experts is urging governments and investors to change course on climate finance for flight, warning that cleaner aviation will not happen without disruptive investment in high‑risk, high‑reward technologies such as hydrogen propulsion, advanced aircraft designs, and large‑scale sustainable fuels. In research published in Science on October 16, 2025, the team argues that while about $1 trillion is expected to flow into aviation over the next decade, most of that money is set to chase safer, familiar projects that only trim fuel burn rather than fundamentally cutting emissions.

“The aviation sector—a fast-growing source of greenhouse gases—illustrates the broader challenge of industrial decarbonization: too little investment in technologies that could yield the biggest climate benefits,” said Professor David G. Victor, UC San Diego, lead author.

The authors propose a tool—the Aviation Sustainability Index (ASI)—to push capital toward projects with the potential to break the link between air travel growth and carbon pollution.

“There needs to be transformation in the aviation sector and the Aviation Sustainability Index could help research managers to make that happen. This index would reward financiers for making investments that make a real difference to aviation’s climate impact,” said Professor Andreas Schäfer, UCL Air Transportation Systems Laboratory, co-author.

The idea is to give banks, airlines, manufacturers, and public agencies a clearer way to distinguish between incremental efficiency upgrades and technologies that could enable deep decarbonization at scale.

Their intervention comes three years after the International Civil Aviation Organization set a historic 2050 net‑zero CO2 goal. Hitting that target, the researchers say, will require up to $5 trillion in technology investments by 2050 alone. They estimate governments should cover between $0.8 trillion and $1.4 trillion—about 20% of the total—over 30 years to derisk the early phases of deployment and give private capital the confidence to back breakthrough platforms. The recommended public spending profile is also specific: direct fiscal support should target research and development and early capital expenditure for emerging technologies, with 95% of subsidies through 2030 recommended for e‑fuels and advanced biofuels, and only 5% for crop‑based fuels.

The researchers stress that disruptive investment means backing unfamiliar technologies and business models that carry higher technical and market risk but could deliver much larger long‑term emission cuts. That includes hydrogen propulsion systems that require new aircraft architectures and airport refueling infrastructure, as well as advanced, electricity‑derived e‑fuels that can be scaled with clean power. It contrasts sharply with today’s capital flows, which favor upgrades that airlines know how to monetize quickly, such as next‑generation jet engines, modest aerodynamic tweaks, or recycled‑fuel pathways that reduce emissions at the margins.

“Cleaner flight is possible, but it requires changing how we think about both risk and return. We need new institutions, incentives, and partnerships that reward innovation, not just incrementalism,” said Professor Victor.

Behind the technical case is an economic warning. Europe’s aviation sector alone supports almost 10 million jobs and accounts for €672 billion in EU economic activity, according to the research, underscoring the socio‑economic stakes of getting decarbonization right. If capital continues to back only safe bets, the authors argue, the sector will miss the window to scale technologies capable of deep cuts, leaving airlines exposed to rising carbon costs and supply shocks in sustainable fuels. If, instead, public and private money is steered to early‑stage hydrogen propulsion programs, new airframe concepts, and sustainable fuels production at industrial scale, the sector could meet climate goals without choking off growth.

The ASI is presented as a practical way to change how money moves. In simple terms, it would score proposed projects not just on near‑term fuel savings but on their potential to decouple emissions from passenger and cargo growth over time. That metric could help pension funds, export credit agencies, and corporate treasurers decide whether to put capital into a new engine upgrade or, alternatively, a disruptive investment in hydrogen‑ready airframes; whether to fund a small refinery retrofit or underwrite a greenfield e‑fuel plant integrated with renewable power. By shifting how managers gauge risk and return, the index is designed to reward projects that can scale and stick, rather than those that yield modest improvements before carbon targets tighten.

The paper’s authors say timelines and amounts matter. They point to the roughly $1 trillion in aviation investment expected across the next decade and warn that, under current trajectories, most of it will not deliver transformative change. That is because capital markets, left alone, typically prefer known technologies with predictable cash flows, especially in a cyclical, safety‑critical industry like aviation. Certification pathways for new propulsion systems are long and complex; airports need costly upgrades to handle hydrogen or high‑volume sustainable fuels; and early plants for e‑fuels and advanced biofuels face volatile input prices. The result is a classic risk‑return mismatch—precisely the gap the ASI and targeted public spending aim to close.

The government role laid out in the research is narrow but forceful. Public money should focus on research and development and on early capital expenditures that prove technology and unlock private finance, the authors argue, rather than on indefinite operating subsidies. They call for 95% of subsidies through 2030 to support e‑fuels and advanced biofuels, which can be made from waste or synthesized with clean electricity, with the remaining 5% for crop‑based fuels to avoid land‑use conflicts. In the United States 🇺🇸, agencies already fund pieces of this work; for example, the U.S. Department of Energy sustainable aviation fuel overview outlines federal support for lowering the cost and scaling production of sustainable fuels. The authors argue that a more explicit, performance‑based index could help align these efforts globally and send clearer market signals.

The paper also offers a reality check on climate rhetoric. The authors note that bold global pledges—such as getting to net zero by 2050—can sometimes be counterproductive when they are not matched with practical, near‑term steps that change what projects get built. In aviation, that means designing finance tools and policies that pull money into hydrogen propulsion pilots, large e‑fuel syntheses tied to renewable power, and radically more efficient airframes, rather than spending the next decade refining incremental engine improvements. Without those shifts, they warn, the sector could lock in another generation of conventional technology that will be difficult to decarbonize later.

Hydrogen propulsion stands out as both a symbol of the challenge and a test case for the approach. Developing aircraft that can store and burn hydrogen safely, at weight and volume constraints acceptable for commercial operations, demands new airframe layouts, cryogenic storage systems, and changes to airport ground operations. For investors, those are formidable risks, but the long‑term payoff—emissions close to zero at the point of use if the hydrogen is produced with clean power—fits the definition of disruptive investment the authors say is required. Similarly, large‑scale plants for e‑fuels and advanced biofuels require multi‑billion‑dollar outlays upfront, long‑term offtake contracts, and confidence that regulations will recognize their carbon benefits. The paper argues that an index like the ASI could translate these technical realities into a comparable score that financiers can use to justify backing them over safer, smaller upgrades.

The authors are clear that sustainable fuels will do much of the heavy lifting during the long transition while hydrogen‑capable aircraft are tested, certified, and deployed. They distinguish, however, between crop‑based fuels—which raise land‑use concerns and provide limited net carbon benefits—and advanced biofuels and e‑fuels, which they argue should dominate subsidy allocations through 2030. By favoring projects capable of scaling rapidly with minimal indirect emissions, public programs can help build the supply chains and infrastructure that reduce costs and attract follow‑on capital at commercial scale.

At the same time, the report’s economic framing reflects the industry’s social footprint. With almost 10 million European jobs and €672 billion in EU economic activity tied to aviation, cleaner flight is not just a technical problem but a strategic one for governments and investors weighing trade‑offs between climate ambition and economic resilience. That reality shapes the call for public outlays of $0.8–1.4 trillion over 30 years: enough to open the door for private money, but focused on de‑risking rather than replacing market investment. The authors suggest that if governments carry early‑stage risks and adopt a consistent scoring framework like the ASI, private investors will be more willing to fund novel aircraft designs and large sustainable fuels projects that can meet demand without surging emissions.

The team behind the study spans universities and disciplines. Alongside Professor Victor and Professor Schäfer, the paper lists Thomas Conlon of University College Dublin, Philipp Goedeking of Johannes Gutenberg University of Mainz, and Andreas W. Schäfer of University College London as co‑authors. Their analysis ties aviation’s path to net zero to broader lessons in industrial decarbonization: where technologies are capital‑intensive, infrastructure‑heavy, and safety‑critical, policy must tilt the early economics to help promising options over the initial hump.

The stakes are high because aviation demand is still growing, especially in emerging markets, and because aircraft and fuel systems have long service lives. If the next wave of fleet and infrastructure spending locks in only modest efficiency gains, the sector will have fewer tools left to reach net zero later, the authors argue. Redirecting even a fraction of the expected $1 trillion over the next decade toward hydrogen propulsion prototypes, full‑scale e‑fuel facilities, and radically efficient airframe designs could change the trajectory. The ASI is meant to help identify which of those projects would deliver the biggest emissions reductions per dollar and per unit of aviation demand.

In practical terms, the authors frame the choice for airlines, airports, and investors as a portfolio problem. A rational portfolio today that aims at net zero by 2050 would keep some capital flowing to proven, efficiency‑boosting retrofits while shifting a larger share into riskier, transformative bets that can scale by the 2030s and 2040s. Those include hydrogen propulsion demonstrators tied to airport infrastructure pilots; offtake‑backed investments in advanced biofuels and e‑fuels; and new aircraft architectures optimized for low‑carbon flight. Doing so, they say, will require lenders and equity investors to adopt different risk metrics—exactly what the ASI is designed to provide—so that a disruptive investment with uncertain early returns but massive climate upside can compete for capital against a safer upgrade with limited emissions impact.

The paper closes on a pragmatic note. Cleaner flight will not come from one silver bullet, but from many shots on goal that are today underfunded because they are unfamiliar and risky. The call for governments to fund 20% of the needed $5 trillion by 2050, the push for 95% of subsidies through 2030 to go to e‑fuels and advanced biofuels, and the introduction of the ASI all point to the same outcome: moving money from incrementalism to innovation.

“Cleaner flight is possible, but it requires changing how we think about both risk and return. We need new institutions, incentives, and partnerships that reward innovation, not just incrementalism,” said Professor Victor.

For an industry that touches nearly every economy and employs millions, the message is that getting to net zero will depend on whether capital markets—and the public policies that shape them—can be redesigned to back hydrogen propulsion, sustainable fuels at industrial scale, and aircraft that look different from those flying today.