CLIMATE MODELLING
The computer screen radiates line after line of strange text: black letters, numbers and symbols on a light grey background. Scrolling through, it seems to be never-ending and – at least for me – mostly unintelligible; I’m not fluent in Fortran, the programming language it’s written in. But there’s a plain English preface to this gobbledegook text.
“Many people have contributed to the development of this code,” it reads. “This is a collective effort and although individual contributions are appreciated, individual authorship is not indicated.”
I’m visiting the Climate Change Research Centre (CCRC) at the University of New South Wales (UNSW), Sydney, and what I’m looking at is the backend of a modern-day climate model – specifically, the University of Victoria Earth System Climate Model (UVic ESCM).
This is just one of many models that scientists use nowadays to peer into Earth’s past and make projections about its future. For example: that our planet is likely to warm 1.5°C above pre-industrial levels in the “near-term” and that “every increment of global warming will intensify multiple and concurrent hazards”, as the IPCC Sixth Assessment report says.
Like many people, I strongly believe these projections. But my belief is based on little more than blind faith in the models that produce them. In fact, I know so little of the inner workings of climate modelling that it seems to me like something of a dark art – a form of planetary-scale fortune telling. The reason I’m here is to break the spell; to see for myself exactly what is behind the curtain of a contemporary climate model.
My guide is Katrin Meissner, director of the CCRC and a professor at UNSW, who melds a brown bob, warm smile and more than 25 years’ experience in climate modelling. She first started developing models while completing her PhD in the mid-1990s at the Alfred Wegener Institute for Polar and Marine Research in Germany, and initially “hated” the computer coding involved. Over time, it grew on her and she came to appreciate its beauty.
“You have to use your brain to try to work out why things don’t work; it’s like a puzzle you have to solve,” she says.
In 2000, Meissner accepted a postdoc position in the School of Earth and Ocean Sciences at the University of Victoria, Canada, where her coding experience and knowledge of
