Aviation needs better measurement to deliver meaningful decarbonisation

SPONSORED ARTICLE

As aviation’s contribution to global greenhouse gas emissions continues to rise, questions are mounting over whether current tools for calculating flight emissions are fit-for-purpose. Most carbon calculators on the market rely on simple distance-based models, overlooking non-CO₂ effects, such as contrails, nitrogen oxides and induced cloud formation. All of these factors amplify the sector’s warming impact and this measurement gap risks the underestimation of aviation’s real carbon footprint. As a response, new research led by Therme Group and the University of Surrey has produced a new model: the Air Travel Passenger Dynamic Emissions Calculator (ATP-DEC). 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 with climate targets, write Eduard Goean and Jhuma Sadhukhan.

As global aviation emissions edge toward record levels, the spotlight is turning on airlines’ tools for estimating their climate impact.

Most existing carbon calculators are narrowly, and it has to be said in many cases inaccurately, focusing on CO₂e and total flight distance. This approach is missing key components of aviation’s true environmental footprint.

Non-CO₂ effects, such as contrails, NO_X emissions and induced cloud formation, are known to be significant global warming drivers, but remain largely excluded or poorly-handled by current aviation tools.

Whether we are willing to face-up to a reality where emissions are being systematically underestimated is an important question for both policymakers and airline decision-makers to address.

By way of example, UK aviation emissions are now accounting for almost 7% of national greenhouse gases, and are projected to rise to 9% by 2025, then 11% by 2030 as other sectors decarbonise.

The UK’s Climate Change Committee (CCC) has warned that aviation emissions could undermine the government’s Jet Zero strategy unless stronger tools and regulations are quickly identified and adopted. The Committee has also urged policymakers to consider pricing aviation emissions more effectively and expanding the UK Emissions Trading Scheme (ETS) to include long‑haul flights.

In addition, the UK Civil Aviation Authority has proposed a new requirement that airlines may soon be required to disclose passengers’ carbon footprints at booking, with results being presented in a standard and accessible format.

Regulators need tools to withstand scrutiny

In response, Therme Group has led the development of the ‘Air Travel Passenger Dynamic Emissions Calculator’ (ATP-DEC for short). This ‘lifecycle-aware’ calculator is designed to capture traditional CO₂ metrics and non-Kyoto impacts, including non-CO₂ effects such as contrails, NO_X emissions and induced cloud formation.

ATP-DEC’s independent design was co-financed by the UK government through the Innovate UK Knowledge Transfer Partnership (KTP) scheme, with leading visitor economy and life-cycle assessment experts from the University of Surrey. The KTP project finances not just the aviation calculator but four others as well: for the spa industry (already completed), hospitality (under development), food & beverage and theme amusement parks (to be developed in 2026).

The novelty and granularity of the research behind the ATP-DEC has convinced the prestigious Nature Communications Earth and Environment journal, after a rigorous peer-review process, to publish the scientific study in the very near future. It will be available on an open access basis, which will allow anyone the ability to review, replicate and utilise the ATP-DEC methodology.

This new model of carbon calculator recognises the full life-cycle analysis of aircraft production and operation, including fuel processing, airport build and aircraft operation, in-flight services, seating class, baggage allocation and non‑Kyoto emissions.

It further applies historical adjustment factors to estimate real-world flight paths and loads accurately. For example, most western airlines are banned from flying over Russia, forcing them to take longer routes, while extending flight times and pushing up costs. This is unrecognised by ‘static’ carbon calculators

ATP-DEC has been validated against more than 30,000 actual flights, achieving a mean absolute percentage error of approximately 0.5 per cent, a level of precision we believe unmatched by other tools from IATA, ICAO, Google TIM or MyClimate. It additionally exceeds ISO 14083, the standard for quantifying and reporting greenhouse gas emissions from transport chain operations, by providing traceable, reproducible emissions breakdowns for regulators or independent reviewers.

Why this matters more than ever

With airlines and regulators exploring new mechanisms, ranging from a jet fuel tax and expanding ETS to long‑haul flights, all in the midst of public and political pressure over aviation’s rising footprint, airlines’ approach needs to change, and fast.

Beyond the UK context, ATP-DEC is unique in its global relevance. This is the only aviation carbon calculator that has been fully developed and validated by leading academic researchers. Unlike other tools with opaque origins, ATP-DEC delivers transparency and accountability.

By combining non-CO₂ effects, realistic flight paths and independent LCA, ATP-DEC offers a defensible basis for audits, carbon disclosures and fare-stage passenger information, supporting credible alignment with both national measures and ICAO requirements.

ATP-DEC offers the sector an unbiased and transparent foundation for global carbon disclosure. This tool is designed for deployment on a global scale, and is capable of harmonising passenger footprint reporting across jurisdictions, supporting regulators, airlines and consumers alike in achieving comparability and trust.

Therme Group and University of Surrey are also exploring markets other than the UK, around the world, all of which are moving independently, but similarly on aviation decarbonisation.

In the EU, the big decarbonisation push is ReFuelEU, with sustainable aviation fuel (SAF) at its core. But production is far behind demand and IATA warns that closing this gap will require prohibitive sums.

ATP-DEC is built to work hand-in-hand with a new retail green financing model: the Carbon Tokenomics Model (CTM). Developed by Therme Group with worldwide academic support, CTM uses blockchain-based decentralised-finance to incentivise travellers’ micro-investment into green projects, including SAF production.

Together, ATP-DEC and CTM could finally provide aviation with a transparent, scalable path to accelerate the SAF transition and decarbonisation. Therme Group has already presented this tandem approach to the EU Commissioner for Climate Action.

Worldwide, governments are converging on SAF as the only credible route to aviation decarbonisation. The US has tied clean-fuel tax credits to verifiable emissions savings; Singapore will levy passengers to co-fund SAF blending from 2026; and Japan has launched its first domestic SAF production to meet a 10% target by 2030.

In all these contexts, ATP-DEC gives regulators and airlines a common, life-cycle-based methodology to evidence passengers’ carbon footprint. Combined with CTM’s power to channel retail finance into SAF supply, the tandem provides the missing piece to unlock aviation’s global SAF transition: a transparent, scalable solution that can make national initiatives credible and replicable worldwide.

About the authors

Eduard Goean is Vice-President of New Business Partnerships at Therme Group and Visiting Professor at University of Surrey.

• Mail
• LinkedIn

Professor Jhuma Sadhukhan is UK Lead at the Global Centre for Sustainable Bioproducts, University of Surrey, specialising in life cycle assessment and industrial decarbonisation.

• Mail
• LinkedIn