October 2, 2025
A paper published this week in Geoscientific Model Development provides an overview of the seventh phase of the Coupled Model Intercomparison Project (CMIP). This international research activity brings together the world’s leading climate modelling centres to evaluate the different climate and Earth system models used around the world. Australia submits models to the project by mobilising a large-scale initiative of researchers from many disciplines and institutions, collaborating closely with software engineers.
“CMIP is about asking and trying to answer some key questions we have about how the climate system works and how it is going to change with increasing greenhouse gases and other changes in the atmospheric constituents,” says Monash University Professor Julie Arblaster, co-author of the paper.
Australia is submitting one model configuration, ACCESS-ESM 1.6. for the FastTrack component of CMIP7.
“Australia’s participation this international collaboration is crucial. CMIP7 is not only about feeding information into the Intergovernmental Panel on Climate Change (IPCC), but it is also essential for national climate and risk assessments and climate information at that regional and local scale,” says Professor Arblaster.
For this submission, CSIRO will lead a consortium including Australia’s climate simulator (ACCESS-NRI), the National Computational Infrastructure (NCI), the Bureau of Meteorology (BoM) and several Australian Universities, working alongside existing national and international collaborations.
“On top of our commitment to participate in CMIP7 with ACCESS ESM1.6, we are also working towards completing a newer version of the model, ACCESS-ESM3, in time for CMIP7 (after FastTrack). This development is key to improve the simulations, but is still subject to funding,” says Professor Andy Hogg, Director of Australia’s climate simulator (ACCESS-NRI).
Other CMIP7 activities where ACCESS-NRI and the ACCESS Community are participating, include the CMIP7 Community Workshop 2026 which will take place next March 2026 in Kyoto, Japan. This Workshop aims to bring together the whole community that has created the CMIP framework and analyse the first runs from CMIP7.
More about the paper
The paper, entitled “An evolving Coupled Model Intercomparison Project Phase 7 (CMIP7) and Fast Track in support of future climate assessment,” sets out the objectives, structure, and scientific rationale for CMIP7. CMIP develops coordinated experimental protocols within the World Climate Research Programme (WCRP) for global coupled atmosphere-ocean-land-ice climate and Earth System Models (ESMs) and facilitates the distribution and interpretation of simulation output.
The paper sets the scene for modelling groups around the world on CMIP7 coordinated experiments that promise to provide insights into four fundamental research questions:
- Patterns of sea surface change: How will tropical ocean temperature patterns co-evolve with those at higher latitudes?
- Changing weather: How will dangerous weather patterns evolve?
- Water-carbon-climate nexus: How will Earth respond to human efforts to manage the carbon cycle?
- Tipping Points: What are the risks of triggering irreversible changes across possible climate trajectories?
The paper also describes 120 guidance on protocols for the mandatory Diagnostics, Evaluation, and Characterization of Klima (DECK) and recommended “Assessment Fast Track” experiments. It concludes with discussion of the evolving role of CMIP in the research community.
Key advances of CMIP7 compared with CMIP6 include:
- Expansion of baseline experiments
- Focus on CO2-emissions-driven experiments
- Sustained support for community Model Intercomparison Projects (MIPs)
- Periodic updating of historical forcings and diagnostics requests
- Collection of prioritised experiments, or “Assessment Fast Track”, drawn from community MIPs to support climate research, assessment, and services goals across prediction and projection, characterization, attribution, and process understanding.
Link to the original paper
Link to paper: https://gmd.copernicus.org/articles/18/6671/2025/gmd-18-6671-2025-relations.html–6700.