We used LOVECLIM, an Earth system model of intermediate complexity to perform simulations of the Holocene, the last millennium and the third millennium climates, as well as sensitivity experiments to identify the behaviour of the model under increased greenhouse gas concentrations and freshwater hosing. Moreover, we identified several parameter sets that yield different responses of the LOVECLIM model to a scenario of doubling of CO2 concentration and to freshwater hosing, although the simulated present-day climate remains within the range of observations. The parameter values were chosen within their range of uncertainty. There are nine “climatic” parameter sets, three “carbon cycle” parameter sets and three “ice sheet” parameter sets. Past and future climate simulations were performed with all or a subset of these 81 combinations of parameter sets. The model was run either with fixed-prescribed ice sheets or with an interactively coupled Greenland and Antarctic ice sheet model. Simulations of past climates were conducted in order to identify the subset of parameter sets that allow the best reproduction of observations and reconstructions. Simulations of future climate change then provided a range of model responses that were validated against past climate changes.