We describe the coupling of a three-dimensional ocean circulation model, with explicit thermodynamic seaice and ocean carbon cycle representations, to a two-dimensional atmospheric/land model. This coupled system has been developed as an efficient and flexible tool with which to investigate future climate change scenarios. The setup is sufficiently fast for large ensemble simulations that address uncertainties in future climate modeling. However, the ocean component is detailed enough to provide a tool for looking at the mechanisms and feedbacks that are essential for understanding the future changes in the ocean system.
        Here we show results from a single example simulation: a spin-up to pre-industrial steady state, changes to ocean physical and biogeochemical states for the 20th century (where changes in greenhouse gases and aerosol concentrations are taken from observations) and predictions of further changes for the 21st century in response to increased greenhouse gas and aerosol emissions. We plan, in future studies to use this model to investigate processes important to the heat uptake of the oceans, changes to the ocean circulation and mechanisms of carbon uptake and how these will change in future climate scenarios.