CMIP has long been a cornerstone of international climate research and assessment. The upcoming article “An evolving Coupled Model Intercomparison Project Phase 7 (CMIP7) and Fast Track in support of future climate assessment,” (Dunne et al., 2025) presents the scientific motivation and experimental framework for CMIP7, with the Assessment Fast Track designed to provide timely scientific input to upcoming policy assessments, including the seventh IPCC Assessment Report (AR7).
Beyond it’s use in research, CMIP data has become an important data provider for numerous downstream communities, including but not limited to, the Coordinated Regional Downscaling Experiment (CORDEX) and the Intersectoral Impacts MIP (ISIMIP), and Governmental, academic, and commercial organisations. This role of CMIP as a climate data provider has distinct requirements its role in the research community.
To address the question of how CMIP could continue to support the needs of both the research and applications communities, a working group led by CMIP Panel co-chair Helene Hewitt (Met Office, UK) have scoped a potential ‘Sustained Mode CMIP’ which should provide high demand data on a frequent, regular schedule.
In an upcoming commentary paper, Hewitt et al., 2025, and supported by the Nature piece this vision is outlined. The key elements of this vision include:
- Regular extensions of historical forcings and corresponding regular simulations of the historical past provided on an annual timescale.
- Aligning Earth System Model scenario projections to the five-year cycle of the Global Stocktake. This also aligns reasonably well with current model development pipelines in modelling centres.
Alongside the Hewitt et al., 2025 commentary, Vaishali Naik (CMIP Forcings Task Team co-lead, GFDL/NOAA) led the publication of a Nature comment ‘Climate models need more frequent releases of input data — here’s how to do it’. This paper urged for a shift from the current five-to-seven-year update cycle of forcings data to annual releases to facilitate this Sustained Mode vision.
