Second phase of paleoclimate modelling intercomparison project

By devoting an entire chapter of the fourth assessment report (AR4) to paleoclimates, the Intergovernmental Panel on Climate Change (IPCC) has recognized that studying past climates is essential for comprehending the climate system, and hence for predicting its future evolution. In particular, numerical simulations of past climates, different from today constitute an independent test of the performance and reliability of the general circulation models commonly used for climate predictions. This idea is the motivation for the Paleoclimate Modelling Intercomparison Project (PMIP), a long-standing initiative endorsed by the World Climate Research Programme and the International Geosphere and Biosphere Programme. The focus has so far been on two reference periods, chosen as being the most representative of cold and warm climate intervals in the recent past: the Last Glacial Maximum (LGM, 21,000 years ago) and the mid-Holocene (6000 years ago).