Green flight paths could pave the way for sustainable aviation, new research shows

New research suggests that the creation of ‘green flight paths’ between key global hubs could accelerate the transition to fully decarbonised aviation. The study, led by an international team from Heriot-Watt University in the UK and the American University of Sharjah in the UAE, proposes that long-haul flights with high passenger volumes, such as those between London and Dubai, could serve as models for these green flight corridors. The research, published in the Energy and Environmental Science journal, advocates for using these routes to demonstrate and expand the use of sustainable aviation fuels (SAF).

SAF, which are non-petroleum-based fuels, emit significantly fewer greenhouse gases compared to traditional fossil jet fuels. With airports like London Heathrow and Dubai International already among the busiest in the world—and among the largest sources of CO₂ emissions from international flights—these locations present an ideal opportunity to showcase the potential of SAF in large-scale commercial aviation. Heathrow, for example, is already a leader in SAF adoption, aiming to integrate 11% SAF into its fuel mix by 2030.

One of the major advantages of SAF is its compatibility with existing aviation infrastructure. It can be used in current aircraft engines and fuel systems without requiring major modifications, making it a more feasible option for airlines to implement quickly. According to the researchers, establishing green flight paths could stimulate the large-scale investment necessary to drive the global adoption of SAF and accelerate the aviation sector’s decarbonisation.

Professor Steve Griffiths, Vice Chancellor for Research at the American University of Sharjah and lead author of the study, emphasised the opportunity for both the UAE and the UK to lead the charge in this effort. He stated, “Given the UAE’s and UK’s heavy reliance on long-haul flights, these nations have a compelling chance to pioneer green flight paths. These routes could not only drive the decarbonisation of aviation but also foster international collaboration on SAF and the clean technologies required to reach global net-zero targets by 2050.”

The idea of green flight paths draws inspiration from the success of "green shipping corridors," which are accelerating the shift to net-zero maritime transport. Professor John Andresen, Associate Director of the Research Centre for Carbon Solutions at Heriot-Watt University and co-author of the paper, explained that a similar framework for aviation could help to spur the global production and use of SAF technologies, highlighting the urgency of prioritising long-haul flight segments.

Despite the potential of SAF, the widespread availability of sustainable flights remains a distant goal. Currently, SAF production stands at just 0.1% of the levels needed to meet the 2050 net-zero target set by the international community. One major barrier is the high cost of SAF production, which is still in its early stages. Significant investment is needed to reduce production costs and scale up SAF production.

Focusing on a small number of high-volume long-haul routes could help prove the economic viability of green flight paths. These routes, often located near industrial clusters already working toward decarbonisation, would provide a way to demonstrate SAF’s commercial potential while speeding up the development of viable SAF supply chains.

The researchers also highlight the "climate justice" aspect of green flight paths. Only around 10% of the world’s population currently flies, so it is particularly important for countries with the highest aviation demand to lead the way in developing sustainable solutions. As global incomes rise, and with it the demand for air travel, scalable solutions will become even more critical.

This research was funded by the UK’s Industrial Decarbonisation Research and Innovation Centre (IDRIC), supported by the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI).

Professor Mercedes Maroto-Valer, IDRIC Director, is currently attending COP29 in Baku, Azerbaijan, to further the global dialogue on climate action and progress decarbonisation goals in sectors like aviation, energy, and manufacturing.