“Climate models reflect environmental behaviour”. An Interview with Gabriele Gramelsberger
Dr. Gramelsberger, in your book Computerexperimente: Zum Wandel der Wissenschaft im Zeitalter des Computers (2010) (i.e., Computer Experiments: On the Transformation of Science in the Age of Computers ) you describe how computers are profoundly changing the practices of climate researchers. How important is the computer for climate scientists?
When about 1920 Lewis Fry Richardson tried to calculate by hand the air pressure change for four grid points of a climate model – this was the first attempt at a numerical weather prediction – he needed six weeks for it. In the end his calculations were completely wrong. With the computing power of today’s computers we can calculate very complex models with many more grid points.
For climate researchers, the computer is a ubiquitous tool. It’s used by scientists to exchange information, to do research, to do experiments and to make forecasts. We’re seeing a methodological revolution in the natural sciences, triggered by computer-based experiments.
When the computer creates knowledge
What does that really mean?
By addressing complex natural processes, climate researchers have left the secure framework of mono-causal relationships. In this knowledge process the computer is playing a very decisive role as a new tool of knowledge production.
My thesis is that this transformation in knowledge production can be explained less by institutional and structural changes and more by the tremendous importance of computer experiments for researchers, with climate researchers leading the way.
Reducing the rate of error
Who develops the programmes used by climate researchers?
The climate researchers themselves. These programmes are based on Fortan, the oldest computer language in the world, developed by programmers at IBM in 1954. With its help, mathematical formulas can be relatively readily translated into a programming code that’s easy to read. And this readability enables the exchange of codes.
What is the benefit for research institutes when they can exchange programming codes with each other?
It reduces the rate of error, leads to better results and saves time. The core of climate models is scientific theories. These were developed about two to three hundred years ago.
Researchers at the Max Planck Institute for Meteorology in Hamburg, who have developed a climate model for the Intergovernmental Panel on Climate Change (IPCC), have, for example, adopted and modified the weather forecast model of the European Centre for Medium-Range Weather Forecasts (ECMWF) in Reading. For researchers it makes sense to draw on existing weather models and adapt and change them for future climate modelling.
“Decades of collective paperwork”
Is there a point at which simulations become fictions?
A computer simulation becomes a fiction when it lacks an empirical basis: when a researcher relies on assumptions that have insufficient empirical data. The enterprise of science is empirical. Climate researchers therefore seek to incorporate in models only those theories that are backed up empirically.
Why should society rely upon scientific statements based on simulations?
The measuring instruments used by climate researchers developed over decades before they reached their present stage. Climate research is a collaborative enterprise in which thousands of researchers all over the world take part. Their models rest on decades of collective paperwork.
A new kind of knowledge
What do climate models tell us?
Climate models are based on fundamental physical assumptions. They show us that the climate is a huge thermal power pump doing work. We human beings have lived for about 10,000 years in a relatively stable climate zone. Our survival depends on there not being any too great fluctuations in climate.
What epistemic or philosophical value do computer simulations have for climate research?
They provide a new kind of knowledge, which, while allowing no clear statements about what is true or false, reflects complex relationships. Climate models synthesize diverse theoretical approaches, but this doesn’t permit better explanations of natural processes in a linear progression. They are rather complex structures of effects and feedback. They are subject to a different research logic than traditional scientific instruments of knowledge, which examine experimentally only a single slice of reality, but for that reason produce reliable knowledge.
The complexity or synoptic knowledge that we have become acquainted with from climate modelling is increasingly becoming a part of our general view of the world. Climate models hold up a looking glass to our environmental behaviour. That’s something new.
conducted the interview. He is a science writer and journalist based in Bonn.
Translation: Jonathan Uhlaner
Copyright: Goethe-Institut e. V., Online-Redaktion
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