CLEVER has established a strong foundation for a harmonised framework on transport emission factors. The project mapped more than 400 key actors, including research bodies, fuel producers, standardisation and certification organisations and public authorities, to identify those shaping greenhouse gas calculation in transport. This work led to the creation of the CLEVER Expert Forum, a group of 56 specialists from across the transport and energy sectors that provides ongoing review and ensures that the framework meets both scientific and practical needs.
A major result is the CLEVER Repository, an open knowledge platform gathering information on emission factor methodologies, standards, and regulations. It compiles key literature, datasets, and policy documents into a single reference point and hosts the Emission Factor Knowledge Database, which combines findings from more than 40 studies, 25 legislative acts and 20 global initiatives. The analysis highlighted inconsistencies in how emissions are calculated and data gaps for new fuels such as hydrogen, e-fuels and recycled carbon fuels.
Based on these insights, the consortium has defined the methodological structure of the harmonised framework. It sets system boundaries under the Well to Wheel or Well to Wake principle, defines a functional unit based on energy content, and standardises allocation rules for shared production processes. The methodology also covers biogenic carbon, land use change and indirect emissions, ensuring consistent treatment of all energy carriers. These foundations align with ISO 14083 and serve as a key reference for the CountEmissions EU initiative.
CLEVER is now developing the common dataset of harmonised emission factors and user guidance for industry and policy. Reference data are being compiled and tested with stakeholders, with the next steps focusing on validation through industrial case studies and the preparation of training materials to support broad adoption of the methodology in Europe and internationally.
