CMIP6

CMIP6
Name	CMIP6
Caption	Sixth phase of the Coupled Model Intercomparison Project
Established	2016
Organizer	World Climate Research Programme; Intergovernmental Panel on Climate Change
Scope	Global climate model intercomparison

CMIP6

CMIP6 is the sixth phase of the international coordinated climate model intercomparison effort organized under the World Climate Research Programme and timed to inform the Intergovernmental Panel on Climate Change assessment cycles; it builds on earlier phases linked to IPCC Fifth Assessment Report processes and engages national modelling centres such as Met Office Hadley Centre, NOAA Geophysical Fluid Dynamics Laboratory, and Max Planck Institute for Meteorology to produce standardized projections for use by research, policy and international bodies including the United Nations Framework Convention on Climate Change and the Group of Seven.

Overview

CMIP6 expanded the tradition established by the Atmospheric Model Intercomparison Project and the Coupled Model Intercomparison Project earlier phases, coordinating experiments across institutions like NASA Goddard Institute for Space Studies, Centre National de Recherches Météorologiques, Commonwealth Scientific and Industrial Research Organisation, and Lawrence Livermore National Laboratory while interfacing with programmes such as CMIP5 legacy initiatives, the Coupled Model Intercomparison Project Phase 5, the World Climate Research Programme's Working Group on Coupled Modelling, and the Global Carbon Project to address questions central to Paris Agreement goals and assessments by the Intergovernmental Panel on Climate Change.

Experimental Design and Scenarios

CMIP6 introduced a multi-faceted experimental design incorporating the Scenario Model Intercomparison Project (ScenarioMIP), the Detection and Attribution Model Intercomparison Project (DAMIP), and the Decadal Climate Prediction Project (DCPP), coordinating historical forcing experiments tied to observations from HadCRUT4, aerosol forcing datasets from AERONET, and greenhouse gas trajectories consistent with pathways like those used by the Representative Concentration Pathway community and successor frameworks aligned with the Shared Socioeconomic Pathways developed by the Integrated Assessment Modeling community and institutions such as the International Institute for Applied Systems Analysis.

Participating Models and Institutions

Hundreds of model realizations were contributed by modelling centres including the Met Office Hadley Centre, Japan Agency for Marine-Earth Science and Technology, Deutsches Klimarechenzentrum, Max Planck Institute for Meteorology, National Center for Atmospheric Research, and Centre National de la Recherche Scientifique, using atmosphere models like HadGEM3, ocean models such as NEMO, sea-ice components from projects linked to CICE, and land-surface schemes related to Community Land Model work, with coordination by data portals including the Earth System Grid Federation and guidance from bodies like the World Climate Research Programme and the Global Climate Observing System.

Data and Output Products

CMIP6 produced standardized output variables following CF Conventions and NetCDF formats served through repositories run by the Earth System Grid Federation, providing diagnostics and model output tailored to stakeholders including the Intergovernmental Panel on Climate Change, the European Commission's climate services, and national agencies like Environment and Climate Change Canada for use in impacts assessments, regional downscaling projects such as those affiliated with CORDEX and PRISM, and cross-disciplinary analyses involving the Global Carbon Project, IPSL datasets, and observational syntheses from NOAA and Met Office archives.

Major Findings and Applications

Analyses leveraging CMIP6 outputs informed IPCC Sixth Assessment Report chapters on climate sensitivity, attribution, and regional impacts by documenting equilibrium climate sensitivity ranges for models from institutions like the Max Planck Institute for Meteorology and NOAA GFDL and supporting applications in adaptation planning for entities such as the European Commission, water resource assessments for basins studied by the World Bank, and extreme-event attribution studies coordinated with World Weather Attribution and national weather services including UK Met Office and NOAA National Weather Service.

Evaluation, Limitations, and Criticisms

CMIP6 prompted scrutiny over issues such as emergent high climate sensitivities in some models produced by centres like MPI-M and debates involving the Intergovernmental Panel on Climate Change review process, concerns about inter-model independence raised by statistical studies at Princeton University and Imperial College London, data accessibility and reproducibility challenges discussed by the Earth System Grid Federation and European Centre for Medium-Range Weather Forecasts, and the need for improved representation of processes studied by programmes like GEWEX and SPARC while policymakers including the United Nations Framework Convention on Climate Change and funders such as the European Research Council weighed implications for scenario use.

Category:Climate modeling