Advanced flight emissions calculator built by Surrey shows the real cost of flying

By Georgie Gould

Many carbon calculators used by airlines and travel companies are dramatically underestimating the real climate damage caused by air travel, according to new research from the University of Surrey.

The team, which includes Professor Xavier Font from the Centre for Sustainability and Wellbeing in the Visitor Economy, and Professor Jhuma Sadhukhan, Dr Jonathan Chenoweth and Finn McFall from the Centre for Environment and Sustainability, have developed a tool that shows the true footprint of a flight can be more than double current industry estimates – especially for premium passengers.

The Air Travel Passenger Dynamic Emissions Calculator (ATP-DEC) is the first to account for the full life cycle of flying. It includes not only CO2 but also other warming effects such as nitrogen oxides, water vapour and contrail-induced cloudiness, which most calculators ignore. These “non-Kyoto” impacts can be more than twice the size of the CO2 emissions from a flight.

The study, published in Nature Communications Earth and Environment, also factors in upstream emissions from fuel production and in-flight services, as well as the environmental cost of airports and aircraft over their lifetimes. It adjusts for real-world flight paths using historical flight path data, capturing the extra fuel burn from diversions, delays and airspace closures – something static calculators cannot do.

We have proved that existing flight data can capture real-world variations. By delivering a transparent, source-by-source breakdown of emissions per flight, travellers and policymakers can make smarter, targeted climate decisions. Finn McFall, Knowledge Transfer Partnership Associate and co-author of the study

“By combining life-cycle analysis with real-world flight data, ATP-DEC will provide regulators, airlines and passengers with far more accurate and transparent information on carbon disclosure, helping align aviation industry with climate targets and the newest regulations in EU.” Eduard Goean, Visiting Professor at the University of Surrey and VP of Therme Group

The aviation sector has a responsibility to be honest about the environmental cost of flying. Without accurate data, we cannot design effective taxes, offsets or behaviour changes. Our tool puts robust, transparent science into the hands of those who can drive real change. Professor Xavier Font, co-author of the study and Professor of Sustainability Marketing at the University of Surrey

Benchmark tests against over 30,000 flights show ATP-DEC’s estimates closely match actual post-flight data, compared with substantial under-reporting by leading calculators. On some long-haul routes, standard methods understated per-passenger emissions by tens of thousands of tonnes in a single year. For example, the closure of Russian airspace means that many long-haul flights between Europe and Asia take detours of thousands of kilometres, consuming more fuel, and producing more emissions. The ATP-DEC captures this operational variation, while existing static calculators cannot.

Airlines, booking platforms and policymakers could integrate ATP-DEC into their systems immediately. Its modular design means it can evolve with new aircraft types, sustainable fuels and more advanced climate models. It also links directly to blockchain-verified carbon offsetting projects, making it easier to take credible action.

Industry-wide, this model could set a new benchmark for climate transparency, replacing outdated tools that mislead the public and delay action on aviation’s environmental impact. Professor Xavier Font, co-author of the study and Professor of Sustainability Marketing

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Note to editors:

Finn McFall and Professor Xavier Font are available for interview, please contact mediarelations@surrey.ac.uk to arrange.
The full paper is available in Nature Communications Earth and Environment