Comparing three different methods to model scenarios of future glacier change in the Swiss Alps

Ongoing atmospheric warming causes rapid shrinking of glaciers in the European Alps, with a high chance of their near-complete disappearance by the end of the 21st century. Here we present a comparison of three independent approaches to model the possible evolution of the glaciers in the Swiss Alps over the 21st century. The models have different levels of complexity, work at a regional scale and are forced with three scenarios of temperature increase (low, moderate, high). The moderate climate scenario gives an increase in air temperature of 28C and 48C for the two scenario periods 2021–50 and 2070–99, respectively, resulting in an area loss of 60–80% by 2100. In reality, the shrinkage could be even faster, as the observed mean annual thickness loss is already stronger than the modelled one. The three approaches lead to rather similar results with respect to the overall long-term evolution. The choice of climate scenarios produces the largest spread ( 40%) in the final area loss, while the uncertainty in present-day ice-thickness estimation causes about half this spread. DOI: https://doi.org/10.3189/2013AoG63A400 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-81541 Published Version Originally published at: Linsbauer, Andreas; Paul, Frank; Machguth, Horst; Haeberli, Wilfried (2013). Comparing three different methods to model scenarios of future glacier change in the Swiss Alps. Annals of Glaciology, 54(63):241253. DOI: https://doi.org/10.3189/2013AoG63A400 Comparing three different methods to model scenarios of future glacier change in the Swiss Alps Andreas LINSBAUER,1 Frank PAUL,1 Horst MACHGUTH,1;2 Wilfried HAEBERLI1 1Department of Geography, University of Zürich, Zürich, Switzerland E-mail: [email protected] 2Geological Survey of Denmark and Greenland, Copenhagen, Denmark ABSTRACT. Ongoing atmospheric warming causes rapid shrinking of glaciers in the European Alps, with Ongoing atmospheric warming causes rapid shrinking of glaciers in the European Alps, with a high chance of their near-complete disappearance by the end of the 21st century. Here we present a comparison of three independent approaches to model the possible evolution of the glaciers in the Swiss Alps over the 21st century. The models have different levels of complexity, work at a regional scale and are forced with three scenarios of temperature increase (low, moderate, high). The moderate climate scenario gives an increase in air temperature of !28C and !48C for the two scenario periods 2021–50 and 2070–99, respectively, resulting in an area loss of 60–80% by 2100. In reality, the shrinkage could be even faster, as the observed mean annual thickness loss is already stronger than the modelled one. The three approaches lead to rather similar results with respect to the overall long-term evolution. The choice of climate scenarios produces the largest spread (!40%) in the final area loss, while the uncertainty in present-day ice-thickness estimation causes about half this spread.