On September 11, Prof. Hartmut Graßl, Director Emeritus at the Max Planck Institute for Meteorology (MPI-M) and Professor Emeritus at the Meteorological Institute at the University of Hamburg, will receive the highest distinction from the European Meteorological Society, for his “leading role in shaping climate science and his exceptional ability to communicate climate science to his colleagues, to politicians and to the public.” The 73-year-old spoke with us about the development of climatology from an exotic discipline to multi-million dollar “big science”, and about how scientific discoveries are finding their way into everyday politics.
CliSAP: Professor Graßl, you’ve been working in climate research for over 40 years, you were there at its beginning and campaigned on the subject long before people were aware of climate change - neither in Germany nor internationally. You’ve raised awareness among politicians and officials and were director of the “World Climate Research Programme” for five years. Could you have imagined any of this when you started studying in Munich? How did you become interested in climate research?
Graßl: I had an excellent, far-sighted and visionary teacher, Prof. Möller at the Ludwig Maximilians University in Munich, where I began my meteorological degree. In his own doctoral thesis back in 1932, he developed a nomogram for determining the net longwave radiation flux in the atmosphere for the three major climate gases: water vapor, CO2 and ozone, which Smagorinsky, Manabe und Wetherald used in their first three-dimensional climate models at Princeton.
CliSAP: While you were studying, did you have any idea in which direction climate research would be heading?
Graßl: Yes, of course! I believed my teacher, Fritz Möller. Initially I studied meteorology because I thought it was the easy option. But I quickly realized that there was a lot of mathematics and physics involved (laughs). After finishing my intermediate diploma, I changed to physics. Professor Bopp, the chair holder for theoretical physics – one of the “Göttingen Eighteen”*1, but I didn’t know this at the time – tested me briefly on theoretical mechanics, and then he wrote on my meteorology intermediate diploma: “This certificate includes basic studies in physics” and with that I was a physics student and I never went to another compulsory meteorology lecture, even though it was my minor.
CliSAP: At that time, unlike today, climate science as such didn’t exist.
“In the beginning the climatologists were a subset of the meteorologists”
CliSAP: No, the climatologists were a subset of the meteorologists and mainly made a weather synthesis based on statistical methods, but they were also responsible for running a lot of weather stations. As a student – before I went into climate research – I interrupted my studies to take part in an expedition on board the research ship “Meteor” for a year. At the time Fritz Möller and Heinrich Quenzel had initiated a project to study the absorption capacity of aerosols in the South Atlantic. This was a highly innovative topic back then. We carried out the research in the South Atlantic at 8°S because the atmosphere there had hardly been affected by man and only natural aerosols were present, apart from maybe soot from vegetation fires in Africa. First, I helped to prepare a container lab in Munich, and then in a shipyard in Hamburg I installed the equipment and finally spent four months on board the “Meteor” using the interference-filter actinograph to perform measurements with Mr. Quenzel.
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