THE ANTARCTIC ICE SHEET A Paleoclimate Modeling Perspective

The Antarctic Ice Sheet is the largest potential contributor to future sea level rise. Models and paleoceanographic data are often used to examine the past behavior of the ice sheet during both cooler and warmer intervals to understand the forcing and feedbacks that influence ice sheet behavior. Marine geologic studies have focused on understanding ice sheet response during warmer intervals, including the middle Miocene and Pliocene, that have been considered potential analogues to future anthropogenic climate change. Here, we discuss ice sheet modeling and the ways that marine geologic data are used to constrain ice sheet models of the Antarctic Ice Sheet during past warm intervals. We focus on the key challenge of simulating retreat of the "marine" and "terrestrial" sectors of the ice sheet in the geologic past. By integrating ice sheet models and geologic records, we can better characterize the processes that drove past ice sheet retreat. A more complete understanding of these processes, based on continuing engagement between the data and the modeling communities, is the key to predicting the ice sheet's future.