Project: TOPOI-CLIMATE-SIMULATION - It is well known that climate conditions affect human living conditions. Prominent examples are water availability or heat spells like in the European summer in 2003. The project addressed the question how climate may have changed in the past 6000 years and thus affected living conditions. As an example, in the last millennia, changes in orbital parameters such as the shape of the elliptical path of the earth around the sun were a source of climate change. However, due to the sparseness of regional reconstructions of climatic variables such as temperature and precipitation, climate models are a useful tool for analyzing possible changes. In the project, state-of-the-art climate models were employed to simulate climate for the period from 6000 years ago until the present. Orbital parameters, greenhouse gases and solar activity are viewed as external forces. Simulations were carried out with low-resolution coupled ocean-atmosphere general circulation models and high-resolution atmosphere models. The research data of the last 6000 years were produced using global and regional climate simulations. Climate models of the present and future climate are applied as background for the simulations. The global climate was simulated in a high spatial resolution by using the so-called time slice approach for chosen periods in the past 6000 years. The subsequent refinement with the regional model allows a gain of information in Europe. Further Information: https://www.topoi.org/ Summary: Global paleoclimate simulations are carried out on the basis of the so-called time slice technique. The simulations are performed with the state-of-the-art global circulation model ECHAM5 (Roeckner et al., 2003) at a spectral resolution of T106 (∼1.125°×1.125°) and 19 vertical levels. Different time slices are selected at a time interval of approx. 1000 years from each other, from 6000 years ago to pre-industrial times. For each time slice a simulation is carried out over a period of 30 years. As boundary conditions prescribed sea ice fraction and sea surface temperatures were used, which were derived from a continuous simulation with transient periods. This simulation was performed with the coupled atmosphere-ocean circulation model ECHO-G, consisting of the ECHAM4 (Roeckner et al., 1996) and the ocean model HOPE (Wolff et al., 1997), at a spectral resolution of T30 (∼3.75◦×3.75◦). Further information on simulation realization can be found in Wagner et al. (2007). Detailed information on the model set-up can be found in Russo and Cubasch (2016). Russo, E. and Cubasch, U.: Mid-to-late Holocene temperature evolution and atmospheric dynamics over Europe in regional model simulations, Clim. Past, 12, 1645-1662, https://doi.org/10.5194/cp-12-1645-2016, 2016.