How complex climate interrelationships can be described in models – and where the uncertainties lie in various climate scenarios – was explained by Dr. Marco Giorgetta of the Max Planck Institute for Meteorology using the Hamburg model ECHAM as an example. A different type of climate model was then presented by Dr. Edilbert Kirk: Compared to the „Supertanker ECHAM“, the „Planet Simulator“ is more like a fast motorboat. For him and his colleagues at the Meteorological Institute, there are often questions to be answered where this relatively “slim” model, which needs less computer time, gives just as good but faster answers.
In other cases, the transition from large to small is more tricky, as Prof. Heinke Schlünzen showed in the example of going from global to regional to local – for example urban – climate calculations, where ever more resolution of details is needed. At the same time, policymakers in Hamburg need to know how the climate on the Elbe and Alster will develop in the future. Models that “think for themselves” were brought into the discussion by the mathematician Jörn Behrens. With his Junior Research Group the professor is developing models which can focus on particularly interesting aspects, for example the processes on the edge of a cloud, and then follow their movement.
For the practical part of the excursion the journalists could choose between a visit to the German Climate Computing Centre (DKRZ), where the supercomputer “Blizzard” can carry out more than 150 trillion calculations in a second, and the boundary layer wind tunnel of the university, in which a model of the City of Hamburg is set up at the moment.