Adam Morton • 23.09.24 • 4 min read

In March of this year the ATI published the first Non-CO₂ Technologies Roadmap, simultaneously launching a funding programme aiming to grow understanding and accelerate technology development in this area. Adam Morton, Head of Technology – Sustainability & Strategy, considers how the ATI’s ambitions complement the non-CO₂ work already underway globally.

The ATI’s Non-CO₂ Technologies Roadmap, launched in March 2024, represented a world first in aviation non-CO₂ emissions. It set out a consolidated industry view on growing understanding of complex atmospheric science around aviation’s wider climate impact and developing technologies to address this.

The launch of the roadmap and associated funding programme follows work already underway to better understand this important area of sustainability. Recognising that the adoption of Sustainable Aviation Fuels (SAF) may also be an important tool in reducing contrails, the EU funded its ECLIF3 project involving Airbus, the German aerospace centre DLR, Rolls-Royce and fuel producer Neste. This work involving two Rolls-Royce powered Airbus A350-900 measured soot emissions and ice particulate, providing further evidence of the possible role of SAF in helping to minimise contrail formation and persistence.

Meanwhile, the EU funded REACT4C project has investigated another promising area to address contrails. This work which is a subset of wider research into tactical re-routing concluded weather dependent flight trajectories can significantly reduce the overall climate impact of aviation. This novel approach categorised weather systems over the North Atlantic and concluded ‘climate friendly routing’ can be adopted taking into account not only carbon dioxide and contrails but also other aircraft emissions. Furthermore, the REACT4C project concluded these benefits can be delivered at moderate cost and possibly incorporated into future Emissions Trading Schemes (ETS).

On the other side of the Atlantic, work has also been underway by a GE Aerospace, NASA, Boeing and DLR team flying NASA’s DC-8 flying laboratory, behind Boeing’s ecoDemonstrator Explorer 737-10. Again the aircraft is fuelled with SAF but with just as much emphasis on how the engines might be able to further contribute towards minimising overall greenhouse gas emissions. It is hoped that analysis of the resulting data will help deliver engines which are more efficient and with better non-CO₂ emission performance.

Despite high quality, well financed work underway in Europe, North America and the rest of the world, huge opportunities still exist for the UK to apply its world-class expertise to the problems of non-CO₂ emissions and their climate effects. Advancements in hydrogen and other zero emission aircraft (ZEA) makes the UK a prime candidate for advancing work on how this new fuel can deliver both carbon dioxide and non-CO₂ reductions. Of particular interest is the interaction of water vapour from hydrogen gas turbine powered aircraft with exogenous aerosols generated at lower altitude.

During the ATI’s development of the Non-CO₂ Roadmap, overseas researchers recognised the relevant world-class capabilities in the UK. This includes leading modelling capabilities in our universities and research organisations, as well as the expertise held in the aerospace organisations present here.

UK strengths in space technology also present opportunities for cross-sector working to accelerate both fundamental understanding and technology development. Integration of atmospheric data from multiple sources, validation of existing models and creation of new ones is a particularly target rich area for UK attention.

To date, much of the focus of international non-CO₂ research has been around contrail formation and persistence. While a number of different mitigatory approaches have been considered, the UK has much to offer in poorly understood areas such as aerosol/cloud interactions and the complex non-CO₂ trade-offs in engine design.

With the first projects coming through the ATI and Natural Environment Research Council funding programmes, it will be possible to see over the next few years where the UK assumes leadership positions to address this very important area of aviation sustainability.

Tackling aviation’s non-Co2 emissions will feature in an expert panel session at ATI Conference 2024 on 8^th & 9^th October at the ICC Wales, Newport. The agenda is out now at www.ati.org.uk/conference where tickets can also be purchased.