Over four decades, the Coupled Model Intercomparison Project (CMIP) has driven massive improvements in the modelled representation of the Earth system, whilst also seeing huge growth in scope and complexity. In its most recent phase, CMIP6, a broad spectrum of scientific questions continue to be answered across twenty-four individual model intercomparison projects (MIPs). However, despite the invaluable science enabled by CMIP6 data, many challenges were faced by the model data providers, data delivery infrastructure, and users, which need to be addressed moving forwards.

The CMIP Panel have developed the design of the CMIP AR7 Fast Track – a novel component of the latest evolution of CMIP’s experimental design. This fast track, focused on the IPCC Seventh Assessment Report (AR7), is a subset of climate modelling experiments that have been identified as vital for climate assessments and for informing policy and decision making. The CMIP Panel, supported by the CMIP task teams, have defined this subset of experiments to reduce the burden placed on modelling centres and maximise computational efficiencies, while continuing to deliver impactful climate model data on assessment and policy relevant timelines.

With CMIP7 simulations due to start in many modelling centres this year, a number of key components are being finalised to enable this. The forcing datasets required to run the DECK are due to be published by the end of February 2025 and the final version (v1.2) of the CMIP AR7 Fast Track Data Request expected by the end of March 2025. Together these components are being developed and delivered by a huge group of scientists across the CMIP community. Additionally, work has begun on developing the CMIP AR7 Fast Track Rapid Evaluation Framework (REF) to enable a systematic and rapid performance assessment of the models uploading AR7 Fast Track data.

The Townhall will feature updates on the forcing datasets (including future scenarios), CMIP7 Data Request, the Rapid Evaluation Framework, and an update from the Fresh Eyes on CMIP group. There will be opportunities throughout the event for community discussion.

We invite our growing community to attend. We will describe ongoing planning for CMIP7, and beyond, highlight engagement and consultation opportunities, and invite attendee feedback and participation. The Townhall will be presented by members of the CMIP Panel, Fresh Eyes on CMIP group, and CMIP7 Task Teams.

Note to EGU - as discussed via email, please could we have this Townhall for 90 minutes rather than 60?