Comparing climate model simulations with observations is a key element in testing the behaviour of GCMs under different environmental conditions. However, reducing the uncertainties in predictions of future climate behaviour under conditions dissimilar from today requires comparison of model simulations with data from deeper geological periods. For example, the climate of the Eocene ~55 million years ago is commonly used to explore climate behaviour at higher temperatures.
At present robust model-data comparison is seldom achieved because model output is rarely directly comparable with climate proxy data. It requires the development of both new model capabilities and proxies that can be calibrated in the present and applied in the past. This session aims to bring together those involved in both modelling climate and the construction of climate records using new or established proxies applied in the Quaternary and/or deeper geological periods. We seek participants able to offer insights into a wide range of climate variables (including temperature, salinity, productivity, precipitation, run-off, pH and pCO2) and proxies (such as microfossil assemblages, alkenones and other biomarkers, element ratios of, e.g. Mg/Ca and Cd/Ca, oxygen and carbon stable isotopes d18O and d13C, radiocarbon d14C, radiogenic isotopes of, e.g. neodymium and lead).