The study of past climate is necessary to quantify the natural variability in the climate system. This is the goal of the interdisciplinary research group COHMAP (Cooperative Holocene Mapping Project). COHMAP has produced some of the best reconstructions in the field of paleoclimatology. The focus of the PI's research has been the Holocene: that interval of time since the last full glaciation about 20,000 years ago. COHMAP's approach has combined rigorous reconstructions of paleoclimate indicators with sophisticated numerical simulations of past climate. In this manner they have been able to place strong constraints on the range of past climate and provide physically-based mechanisms for the changes observed. In this renewal proposal, COHMAP suggests several new goals for their research program, including producing a new set of boundary conditions for the glacial earth which incorporate the new chronology of the deglaciation and new estimates of ice sheet volume and areal extent. This new research is important because it will provide fundamental insight into the nature of climate during the last 20,000 years and provide an excellent test of the sensitivity and accuracy of General Circulation Models. In addition, COHMAP's research will help to identify regions with insufficient information or model/data contradictions. In this manner, COHMAP research will prove most useful to a wide variety of researchers in paleoclimatology.
