The Danish Center for Earth System Science (DCESS) is a small private foundation dedicated to research, teaching and public information on the Earth system. We develop low resolution but comprehensive Earth System Models. We use simulations and projections with these models to explore how the Earth functioned in the past and how it might behave in the future, not the least in response to possible anthropogenic forcing scenarios. We also use our simulations to test proposed mechanisms and feedbacks and to aid in the interpretation of geological/geochemical, meteorological, and oceanographic data sets. With our research we strive to obtain important insights into the coupled nature of climate, ocean circulation, ocean chemistry, land processes, ice cover and life.