A precise glacier model
If things go badly, not much. This is the conclusion reached by Guillaume Jouvet and Matthias Huss from the research group of Martin Funk at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich. In a detailed simulation, the two researchers have tested how the Aletsch Glacier will change over the coming years. They applied a 3D glacier model that allows them to map the dynamics of an individual glacier in detail. “The Aletsch Glacier’s ice movements are particularly complex: three massive ice flows coming down from the mountaintops converge at Konkordiaplatz, and then continue on together into the valley,” Huss explains.
He collaborated on a similar simulation 10 years ago with Jouvet, who at the time was working at EPFL. Now the two researchers have teamed up again to assess the future of the Aletsch Glacier using the new regional climate scenarios for Switzerland (CH2018) that were introduced last autumn. They focused on three scenarios that take widely different starting points regarding the concentration of CO
2
in the atmosphere and thus also assume different levels of global warming.
The best case: 50 percent loss
Regarding glacier tourism in Valais, the best-case scenario would be if global warming could be limited to less than 2 degrees Celsius, as stipulated in the Paris Agreement. For that to happen, however, greenhouse gas emissions have to be massively reduced around the world, and soon, so that the climate can be stabilised from about 2040. “Even in this case, we have to assume that the Aletsch Glacier will keep retreating until the end of the century,” Jouvet says, continuing, “which means both ice volume and length will be reduced by more than half of what they are today.” Large glaciers are very slow to react to changes in climate, and so even if the global climate does stabilise relatively quickly, the Aletsch Glacier will continue to retreat.
