Projected effects of temperature changes on the Italian Western Tauri glaciers (Eastern Alps)

Abstract

A linear model was used to investigate the behaviour of the Italian Western Tauri glaciers as a result of temperature changes projected for the 21st century. The model estimates the temperature variations once the glacier snout length variations are known and vice versa: it estimates the glacier snout length variations once the air temperature variations are known or predicted. The 46 glaciers of the Italian Western Tauri, 35 (76%) of which have areas smaller than 0.5 km 2 and only 7 (15%) larger than 1 km 2 , are mostly mountain type glaciers and only three are presently valley glaciers. The model has been forced by the air temperature projections of the A1B emission scenario, which indicates an increase in temperature of 2.7°C from 2015 to 2100. The results show a shortening of more than 35% for mountain glaciers by 2100 with a surface loss of more than 60% and smaller reductions for valley glaciers. The consequent fragmentation into smaller units would lead to the extinction of 95% of the existing glaciers by the end of the century, possibly leaving only the valley glaciers surviving.

Effects of climate change on the valley glaciers of the Italian Alps

“…Citterio et al (2007) suggest that, in the coming decades, only the few largest glaciers will be in a condition to survive. The last 35 years glacier behaviour shown in the present study indicates a minor sensitivity of the valley glaciers compared both to mountain glaciers of Eastern Alps, analyzed with the same 310 model (Serandrei-Barbero et al, 2019), and to the generality of alpine glaciers, as reported in literature. Therefore, the glacier size and typology could both play a decisive role in the behaviour of valley glaciers under the climate change, but their projections obtained from the model suggest, for valley glaciers, a possible less dramatic trend than expected.…”

“…The application of the model proposed by Oerlemans (2005) to the Tauern Alps glaciers (Eastern Italian Alps), obtained after a recalibration of the climate sensitivity and response time, verified its ability to reproduce the retreat of the glacier fronts even for the glaciers for which length fluctuations data are not available (Zecchetto et al, 2017). On the Tauern Alps in the last 35 years, the frontal retreat of valley glaciers has been less than that of mountain glaciers and this lower climatic sensitivity is 40 also reflected in the projections provided by the model, which are less dramatic for the valley glaciers with respect to mountain glaciers (Serandrei-Barbero et al, 2019). The present work extends these analyses to all the valley glaciers located on the Italian side of the Alps from 2018 to 2100.…”

“…8). Moreover, based on A1B scenario (Nakicenovic et al 2000), also on the Eastern Alps the expected length loss in 2100 between 20% and 35% on the valley glaciers is much less than the mean shortening 300 between 35% and 60% expected on mountain glaciers of the same size class (Serandrei-Barbero et al 2019). The smaller decline of the valley glaciers with respect to the totality of Alpine glaciers is also confirmed by the comparison with the projections of Peano et al (2016): on the studied mountain glaciers in the Italian Western Alps the expected average length shrinkage in 2100 under the future scenarios RCP4.5 and RCP8.5 is respectively 47% and 68.5% and the length would become zero in 2100 for some of these mountain glaciers.…”

“…On the Eastern Alps, a previous comparison between valley and mountain glaciers belonging to the same size classes highlighted the lower retreat of valley glaciers (Serandrei-Barbero et al 2019).…”

Comment on tc-2021-241

“…The application of the model proposed by Oerlemans (2005) to the Tauern Alps glaciers (Eastern Italian Alps), obtained after a recalibration of the climate sensitivity and response time, verified its ability to reproduce the retreat of the glacier fronts even for the glaciers for which length fluctuations data are not available (Zecchetto et al, 2017). On the Tauern Alps in the last 35 years, the frontal retreat of valley glaciers has been less than that of mountain glaciers and this lower climatic sensitivity is 40 also reflected in the projections provided by the model, which are less dramatic for the valley glaciers with respect to mountain glaciers (Serandrei-Barbero et al, 2019). The present work extends these analyses to all the valley glaciers located on the Italian side of the Alps from 2018 to 2100.…”