Today, the CMIP Panel have released a survey to consult the CMIP community on the AR7 Fast Track design.
Over the course of 2023 and early 2024, the CMIP Panel and WGCM Infrastructure Panel (WIP), alongside the CMIP Task Teams, have worked hard to evolve the structure of CMIP to address issues that were faced in CMIP6.
A range of surveys and events have taken place over the past two years to gather data on the successes and reflections from CMIP6. An often raised challenge in CMIP6 was the high burden placed on the modelling centres from a large experiment list, frequently changed data request, and delays to historical forcing dataset provision. This high burden led to data issues and substandard documentation of the data.
The CMIP projections have become heavily relied upon in the Intergovernmental Panel on Climate Change (IPCC)’s Assessment Reports. As such, previous CMIP phases have aligned themselves on the IPCC timelines, to ensure CMIP data and analysis are available for IPCC authors to synthesise in the latest report.
Moving forwards, the CMIP Panel recognised that a change to the experimental design was needed to address the burden placed on modelling centres during CMIP6, while still targeting a data delivery timeline that serves the IPCC and potentially other future climate assessments. Therefore, they have proposed a more continuous approach for model intercomparison along with a targeted “AR7 Fast Track” set of experiments designed to set priorities for the running of simulations to align with the needs, and likely ambitious timeline, of the IPCC 7th assessment cycle.
Today, the CMIP Panel asks the WCRP community, MIPs, CMIP data users, and other community members to consult on their AR7 Fast Track proposal to ensure the new experimental structure suits needs from across the community.
The CMIP AR7 Fast Track proposal
The CMIP fast tracks are designed as a compact set of experiments including the DECK and selected experiments from Community MIPs that will support specific needs. The CMIP AR7 Fast Track is intended to specifically deliver to the IPCC 7th assessment cycle.
This streamlined set of experiments is intended to be performed under a strict timeline aligning with the AR7 requirements. Other experiments, not in the Fast Track, are free to operate on their own timeline, although we understand that some modelling centres/groups may choose to align with the AR7 timeline regardless.
The DECK (CMIP “entry card”) and Fast Track experiments are governed and designed by the CMIP Panel in close consultation with the community. It is important to emphasise that the Fast Track selection does not reflect scientific prioritisation of experiments on any basis apart from timeline. Participation in the Fast Track and Community MIPs is a choice for modelling centres, and participation to the AR7 Fast Track is not a pre-requisite for participation in Community MIPs.
Previous consultation
During 2023, the Strategic Ensemble Design Task Team developed a list of potential Fast Track experiments through task team discussions and brainstorming, and engagement with their stakeholder group and the MIP chairs. This selection was then presented to the Core Panel in September 2023. After further engagement with the proposing MIPs and CMIP Panel discussion the first version (v1) of the CMIP AR7 Fast Track was released for consultation with the modelling centres/groups in December 2023.
The second, open consultation is intended to be a co-production process – your organisation’s input is very important.
The v2 consultation has now closed.
