Palaeoceanographic and palaeoclimatic models often lack boundary conditions that accurately describe the changes in seafloor and land surfaces of a specific geological epoch, or the dynamics thereof over long time periods. For example, modeling the development of major deep-sea currents such as the Antarctic Circumpolar Current, in relation to the opening and closure of oceanic gateways (e.g. Drake Passage, Tasman Strait), remain inaccurate due to the absence of accurate bathymetric reconstructions. This results in uncertainty in estimating the onset of Antarctic glaciation and its palaeoclimatic consequences. This research contributes to the Cenozoic and Mesozoic climate reconstructions by combining a variety of earth system models and deriving new palaeotopographic reconstructions. The most important input parameter for modeling the palaeobathymetry by means of backstripping procedures is a unified plate-tectonic reconstruction of the Southern Ocean region. In addition to a rigid plate approach, this reconstruction model also takes continental deformation into account. Therefore, lithospheric stretching factors of the passive Antarctic and conjugate margins are derived from crustal basement thickness. Consequently more precise regional and global palaeoceanographic and palaeoclimatic scenarios are obtained by integrating these higher resolution palaeotopographic and palaeogeographic grids into existing climate models.