Short answers, pulled from the story.
CMIP is a collaborative framework organized in 1995 by the Working Group on Coupled Modelling of the World Climate Research Programme, designed to improve knowledge of climate change. It coordinates climate model simulations across dozens of international research groups, enabling direct comparison of results. The project is developed in phases to support both scientific understanding and assessments of climate change.
In CMIP, "coupled" refers to computer-based models of Earth's climate in which separate models of different subsystems, such as the atmosphere, oceans, land, and ice, are linked together and interact during simulations. Coupling those subsystems allows the models to capture how changes in one part of the climate system affect others.
By 2018, CMIP6 had endorsed 23 Model Intercomparison Projects involving 33 modeling groups across 16 countries. Planning for CMIP6 began in 2013, and an overview of its design and organization was published in 2016.
DECK stands for CMIP Diagnostic, Evaluation and Characterization of Klima, where "klima" is Greek for "climate." It is a set of common baseline experiments that all participating models in CMIP6 must run, providing a shared foundation on top of which Endorsed Model Intercomparison Projects can address a wider range of specific scientific questions.
CMIP phases have been directly timed to support successive IPCC assessment reports. CMIP3 output helped scientists preparing the IPCC Fourth Assessment Report, CMIP5 results fed into the Fifth Assessment Report, and the deadline for papers contributing to the Sixth Assessment Report Working Group I was set for early 2020, aligned with CMIP6 output.
First data from CMIP7 is expected by the end of 2025. CMIP7 introduces a more continuous release approach, adding fast track experiments that address specific requirements alongside standard DECK releases, rather than delivering all results in a single large batch.