In 2021, ADEME, the French agency for Ecological Transition, published its ‘Transition(s) 2050 Scenarios’ in response to the national low-carbon strategy, with Enerdata providing modelling and scenario development support.
For this publication, ADEME developed the EVEREST model for the ‘Transport’ section. For the next edition of the scenarios, set to be published in 2026, ADEME commissioned the EVEREST version 2 to improve the model’s accuracy.
The model’s interfaces and equations have been adapted to provide a greater level of detail. For example, car transport is now divided into two categories defined by distance - short and long - while freight transport is broken down by distance class. The model also distinguishes between six rail modes and six maritime modes. For air transport, the model includes the three national and international reporting accounting methods. Lastly, four new e-fuels have been added to the seven existing bio-fuels.
Once these developments are made in the model, the challenge lies in populating it with data from the initial year through to 2019. This level of detail requires thorough research and the ability to calculate estimates. The data required, both sought and estimated includes traffic volumes, modal shares, occupancy or load factors, energy efficiencies, and emission factors for each transport mode. Once the data is collected, the model calculates energy consumption and greenhouse gas emissions for 2019. The final step is to calibrate the model so that the calculated energy consumption and greenhouse gas emissions for 2019 align with official reference data.
Enerdata has expertise in developing bespoke models, particularly within the transport sector. For instance, we developed and utilised the first version of EVEREST, adapting it for the mobility and transport forecasting projection the Hauts-de-France region.
ADEME commissioned us to develop EVEREST2, leveraging our knowledge of data sources and estimation methods for model calibration. Our expertise in energy and greenhouse gas accounting also proved invaluable in identifying and correcting discrepancies between the model's outputs and official data.
The development of EVEREST2 was executed with full transparency, enabling ADEME to adapt the equations as needed. A key requirement was that the new interface be highly user-friendly, both for entering assumptions and interpreting the resulting graphs. In total, we collected and estimated a set of 400 variables for 2019, and then assessed the discrepancies between the model's calculations and official statistics.
We provided ADEME with the EVEREST2 model in Excel format, with an integrated user guide, enabling them to generate five prospective decarbonisation scenarios for the transport sector (passengers and freight) up to 2060. The output interface enables users to compare scenarios for a given year, to visualise a scenario’s trajectory between 2019 and 2060, to understand the impact of each lever used by the modeller (sufficiency, efficiency, and renewables), to decompose emissions trajectories into six transport effects (population, demand, modal shift, load factor, energy efficiency, and carbon intensity) using the LDMI method, and, finally, to generate energy/use Sankey diagrams.