Modelling warmer-than-present climates of the past is paramount to understanding the Earth System sensitivity to climate feedbacks deriving from changes in geography, atmospheric chemistry, orbital forcing and ocean circulation. The models offer possibilities to isolate boundary conditions and analyse their impact on the Earth’s climate. Analysing these paleoclimates through modelling also enables model improvements that strengthens our confidence in their ability of detecting and attributing future climate change which is essential for the habitability of most areas in our planet. With this session we aim to discuss current efforts in modelling past warm climates through application of different boundary conditions and modelling intercomparison projects, and to connect scientists in a joint effort of creating a network for informed decision-making on adaptation and mitigation measures under current and future climate change.