Geoscientific Model Development

The climate record of the last millennium holds much promise for identifying the links between forcings and responses at the global, hemispheric and regional scale. The specifications for the Paleoclimate Model Intercomparison Project Phase III (PMIP3) and the Coupled Model Intercomparison Project Phase V (CMIP5) include controlled experiments for the period 850 to 1850 CE. The implementation of those experiments, the collation and development of the climate drivers over this period, and the assessment of the model responses are the focus of this special issue of Geoscientific Model Development.