2025-04-15 update#
IMPORTANT: Errors in Table 1 of Dunne et al, 2025#
We are aware that some of you are already following the An evolving Coupled Model Intercomparison Project phase 7 (CMIP7) and Fast Track in support of future climate assessment preprint Table 1. Some errors have been found regarding the volcanic and solar forcing entries, which will be corrected for final submission. These are highlighted below in bold.
| Experiment short name | Experiment description | Anthropogenic Forcing | Volcanic Forcing | Solar Forcing | Start Year | End Year | Main purpose |
|---|---|---|---|---|---|---|---|
| amip | Atmosphere with SSTs and SICs prescribed | Time-varying | Time-varying | Time-varying | 1979 | 2021 | Evaluation, SST/sea ice forced variability |
| piControl and/or esm-piControl | Coupled atmosphere-ocean pre-industrial control | All 1850, CO2 prescribed concentration or zero emissions | Fixed mean radiative forcing matching historical simulation (i.e. 1850–2021 mean) | Fixed mean value matching first two solar cycles of the historical simulation (i.e. 1850–1873 mean) | 1 | 400+ | Evaluation, unforced variability |
| abrupt- 4xCO2 | CO2 prescribed to 4 times preindustrial | Same as piControl except CO2 concentration prescribed to 4 times piControl | Same as piControl | Same as piControl | 1 (branching from year 101 or later of piControl) | 300+ (1000) | Equilibrium climate sensitivity, feedback, fast responses |
| 1pctCO2 | CO2 prescribed to increase at 1% yr-1 | Same as piControl except CO2 prescribed to increase at 1% yr-1 | Same as piControl | Same as piControl | 1 (branching from year 101 or later of piControl) | 150 | Transient climate sensitivity |
| historical and/or esm-hist | Simulation of the recent past | All time varying, CO2 prescribed concentration or emission | Time varying | Time varying | 1850 | 2021 | Evaluation |
| piClim-Control (amip) | Preindustrial conditions including SST and SIC prescribed | All 1850, CO2 prescribed concentration | Same as piControl | Same as piControl | 1 | 30 | Baseline for model-specific effective radiative forcing (ERF) calculations |
| piClim-anthro (amip) | As piClim-Control except present-day anthropogenic forcing | All 2021, CO2 prescribed concentration | Same as piControl | Same as piControl | 1 | 30 | Quantify present-day total anthropogenic ERF |
| piClim-4xCO2 (amip) | As piClim-Control except CO2 concentrations set to 4 times preindustrial | All 1850 except CO2 prescribed at 4 times preindustrial concentration | Same as piControl | Same as piControl | 1 | 30 | Quantify ERF of 4 × CO2 |
CMIP Panel, WIP and relevant TTs are working on a dynamic format for the
experiment specifications to ensure everyone can access the most up to date
information rather than referring to a static paper going forwards. In the
meantime, for forcings information and descriptions, we strongly recommend
referring to the information/documentation found at https://wcrp-cmip.org/cmip-phases/cmip7/cmip7-forcing-datasets/
linking to the dataset overviews at https://input4mips-cvs.readthedocs.io/en/latest/dataset-overviews/