The Paleoclimate Modelling Intercomparison Project (PMIP) emerged from two parallel endeavours. During the 1980s, the Cooperative Holocene Mapping Project showed the utility of combining model simulations and syntheses of paleoenvironmental data to analyse the mechanisms of climate change. At the same time, the climate-modelling community was becoming increasingly aware that responses to changes in forcing were model dependent. The need to investigate this phenomenon led to the establishment of the Atmospheric Modelling Intercomparison Project (AMIP) - the first of a plethora of model intercomparison projects of which PMIP (and CMIP1) are part.
The specific aim of PMIP was, and continues to be, to provide a mechanism for coordinating paleoclimate modelling and model-evaluation activities to understand the mechanisms of climate change and the role of climate feedbacks. To facilitate model evaluation, PMIP has actively fostered paleodata synthesis and the development of benchmark datasets for model evaluation. During its initial phase (PMIP1), the project focused on atmosphere-only general circulation models; comparisons of coupled ocean-atmosphere and ocean-atmosphere-vegetation models were the focus of PMIP2.
In PMIP3, project members are running the CMIP5 paleoclimate simulations and will lead the evaluation of these simulations. However, PMIP3 will also run experiments for non-CMIP5 time periods and will be coordinating the analysis and exploitation of transient simulations across intervals of rapid climate change in the past. PMIP also provides an umbrella for model intercomparison projects focusing on specific times in the past, such as the Pliocene Modelling Intercomparison Project (PlioMIP), or on particular aspects of the paleoclimate system, such as the Paleo Carbon Modelling Intercomparison Project (PCMIP).
PMIP membership is open to all paleoclimatologists, and we actively encourage the use of archived simulations and data products for model diagnosis or to investigate the causes and impacts of past climate changes.
Quoted from Braconnot et al, "Evaluation of climate models using palaeoclimatic data", Nature Climate Change 2, 417-424 (2012), doi:10.1038/nclimate1456