New EIC report explores the link between jet fuel components and climate-warming contrails

A new study, commissioned by the UK Department for Transport and led by the University of Sheffield’s Energy Innovation Centre (EIC), has investigated how changing the composition of conventional jet fuel can affect its environmental impact. While the focus in sustainable aviation is often on carbon dioxide emissions, this project delves into the role of ‘non-CO₂ emissions’ generated from burning jet fuel, such as soot, in contributing to climate change.

Non-CO₂ emissions are generated from certain chemicals within jet fuel, known as aromatic compounds. The study aims to understand how reducing the quantities of these aromatic compounds can influence the formation of contrails – the white streaks left behind by airplanes. Contrails are responsible for more than half of the warming effect from the aviation industry, by trapping heat in the atmosphere which exacerbates the greenhouse effect.

Professor Mohamed Pourkashanian, Managing Director of the EIC and project lead, highlighted the importance of this work: 

“While we work to develop and scale up cleaner aviation technologies, such as electric aircraft and sustainable aviation fuels (SAFs), the reality is that traditional jet fuels will remain a mainstay for the foreseeable future. Our study seeks to identify potential avenues for reducing the environmental impact of existing fuels to ensure that we make progress on non-CO₂ emissions in the here and now while we work towards a more sustainable future.”

The report found that, due to many uncertainties around safety, feasibility, cost and environmental integrity, reducing the aromatic content of jet fuel carries large risks at present, potentially even having an adverse impact on the environment.  

To that end, the authors recommend an expanded and improved evidence base to better understand if these risks can be mitigated through changes to the production and regulation of jet fuel.

Download full report: Investigating the impact of reducing the aromatic content of kerosene (PDF)

Download executive summary (PDF)