"Continental ice sheets play an important role in the Earth system, holding enough water to raise sea level by several tens of meters. Due to the size and complexity of these systems, numerical models are needed to gain insight into their behavior and so computation has become a central part of the science. With these ideas in mind, this project has three goals: (1) the development of a new coupled climate-ice sheet model (2) advanced research on the stability of the Greenland ice sheet (GIS) during the past; and (3) the estimation of the future contribution of the GIS to sea level rise.In Earth system model development, model usability and reproducibility has rarely been emphasized, often to the detriment of long-term research goals. We will address this issue by building a modeling framework that is highly flexible, user-oriented and based on modern programming practices. We will incorporate and improve an intermediate complexity coupled climate-ice sheet model, a new approach that includes physically based parameterizations of critical feedbacks between the climate and the ice sheet. This will be an investment into the ability of our research group to perform novel simulations and it will provide the foundation for a new line of teaching in geosciences and numerical modeling.We will use this model to investigate the sensitivity of the GIS to climatic changes. We will perform several novel experiments concerning past evolution of the GIS, such as the first glacial inception of Greenland and other warm periods when the GIS contributed significantly to sea levels higher than today. These experiments will not only allow us to answer several open questions concerning the paleo evolution of Greenland, we will be able to constrain model parameters to realistic ranges using paleo data. We will then use the constrained model versions to quantify, in a probabilistic way, the future contribution of the GIS to sea level rise under various global warming scenarios."