Paleoclimate Modeling Intercomparison Project (PMIP)

The Paleoclimate Modeling Intercomparison Project (PMIP) is a long-standing initiative that provides coordinated paleoclimate modeling and data activities to facilitate valuable discoveries on the mechanisms of climate change. It represents and coordinates an established community of researchers from many different countries and disciplines who compare structurally different climate models in a paleoenvironmental context.

During its initial phase (PMIP1), the project focused on atmosphere-only general circulation models for the mid-Holocene (6000 years ago) and Last Glacial Maximum (LGM, 21,000 years ago); comparisons of coupled ocean-atmosphere and ocean-atmosphere models were the focus of PMIP2. PMIP3 expanded to investigating the Last Millennium (850-1850 CE) and then more recently, PMIP4 added the Last Interglacial (127,000 years ago) and mid-Pliocene (3.2 million years ago) to its set of experiments.

As one of the Coupled Model Intercomparison Project Phase 6 (CMIP6) endorsed MIPs, PMIP4 will address the following primary questions:

  1. How well do coupled Earth system models operate beyond conditions under which they have been developed and assessed? (or reproduce climate states that are radically different from those of today?)
  2. What are the roles of climate processes feedbacks arising for the different climate subsystems (atmosphere, ocean, land surface, sea ice, and land ice) on the sensitivity of the climate system and regional climate changes?

The PMIP project has contributed to the Coupled Model Intercomparison Project (CMIP) and the IPCC reports since the 1990s. The characteristic, purpose, and CMIP6 priority of the five PMIP4-CMIP6 Tier 1 experiments are described in the following table. All experiments could be run independently. Each time period also identified additional lower tier (Tier 2 and 3) experiments to investigate additional aspects and provide further understanding of the processes and feedbacks. Details of the simulations for each time period can be found in Jungclaus et al., 2017 for the Last Millennium, Otto-Bliesner et al., 2016 for mid-Holocene and Last Interglacial, Kageyama et al., 2017 for the Last Glacial Maximum, and Haywood et al., 2016 for the mid-Pliocene.

CESM PMIP contributions run on NCAR supercomputers are available on the WCRP’s Earth System Grid Federation. Many are also found on NCAR’s Climate Data Gateway as described within the CESM Paleoclimate Working Group pages here.

PMIP4 Overview paper

The following paper provides an overview of the PMIP4 and its protocols:

Kageyama, M., Braconnot, P., Harrison, S. P., Haywood, A. M., Jungclaus, J. H., Otto-Bliesner, B. L., Peterschmitt, J.-Y., Abe-Ouchi, A., Albani, S., Bartlein, P. J., Brierley, C., Crucifix, M., Dolan, A., Fernandez-Donado, L., Fischer, H., Hopcroft, P. O., Ivanovic, R. F., Lambert, F., Lunt, D. J., Mahowald, N. M., Peltier, W. R., Phipps, S. J., Roche, D. M., Schmidt, G. A., Tarasov, L., Valdes, P. J., Zhang, Q., and Zhou, T.: The PMIP4 contribution to CMIP6 – Part 1: Overview and over-arching analysis plan, Geosci. Model Dev., 11, 1033–1057,, 2018.

For further information, please email NCAR contacts Bette Otto-Bliesner [ ] or Jiang Zhu [ ]

CMIP6 PMIP4 Experiments

Table 1, Kageyama et al. 2018

PMIP Links