“Instrumental observations and reconstructions of global and hemispheric temperature evolution reveal a pronounced warming during the past approximately 150 years.” This is the first line of Christoph Schär’s most cited paper. What’s surprising is that what we see as the consensus in science today was a minor sensation when the paper was published in 2004.
The summer heatwave of 2003 was a “freak event”, and climate science wasn’t really able to explain how it fit into the picture. Schär hypothesised that climate change would cause such extreme events to occur much more frequently in the future – more frequently than would be expected based on average warming alone. Today we know that he was right.
From weather to climate
Schär was born in Wil, in the canton of St Gallen, in 1958.Having always been really interested in the natural sciences, he began studying physics at ETH Zurich, with a view to devoting himself to astrophysics. But things turned out differently. He first landed in the field of weather forecasting, or, more precisely, in the research of low-pressure areas. As it happens, cold fronts and the shower cells behind them are still the weather pattern that Schär finds the most fascinating. “The situation was very different before. We had only a vague idea of where the energy for the formation of a low-pressure vortex came from, and our modelling had a grid spacing of around 100 kilometres. That was only enough to make rough calculations. It wasn’t sufficient for us to fully explain the weather phenomena embedded in low-pressure areas, such as heavy precipitation.”
Those words also describe the core of Schär’s research work: he was forever at pains to model at smaller scales, which not only makes the predictions more precise in terms of time but also increases their relevance because it means they can be applied more locally. “Today, our climate models have a grid spacing of around 2 kilometres – at the start of my career, I would never have believed that we could make such rapid progress,” Schär says. Initially, only a handful of research groups worldwide were active in this field, “and sometimes we were ridiculed,” he goes on to say, smiling. Today, researchers are working across the globe on increasing the precision of climate models.
