reflect in detail processes in the ocean, which have a major influence on the climate. In response, the AWI has developed a special ocean model (FESOM), which simulates e.g. ocean currents and sea ice. For their [...] All around the world, there are natural climate archives – the sediments on the ocean floor, ancient ice in the Arctic and Antarctic, wood for tree-ring analyses, and more. These archives contain what [...] computer programmes used to simulate reality: the motion of air masses, radiation from the sun, and ocean currents – they’re all climate-relevant processes that, with the aid of mathematical formulas, can