How much can we save? Impact of different emission scenarios on future snow cover in the Alps

Abstract

Abstract. This study focuses on an assessment of the future snow depth for two larger Alpine catchments. Automatic weather station data from two diverse regions in the Swiss Alps have been used as input for the Alpine3D surface process model to compute the snow cover at a 200 m horizontal resolution for the reference period (1999–2012). Future temperature and precipitation changes have been computed from 20 downscaled GCM-RCM chains for three different emission scenarios, including one intervention scenario (2 °C target) and for three future time periods (2020–2049, 2045–2074, 2070–2099). By applying simple daily change values to measured time series of temperature and precipitation, small-scale climate scenarios have been calculated for the median estimate and extreme changes. The projections reveal a decrease in snow depth for all elevations, time periods and emission scenarios. The non-intervention scenarios demonstrate a decrease of about 50 % even for elevations above 3000 m. The most affected elevation zone for climate change is located below 1200 m, where the simulations show almost no snow towards the end of the century. Depending on the emission scenario and elevation zone the winter season starts half a month to 1 month later and ends 1 to 3 months earlier in this last scenario period. The resulting snow cover changes may be roughly equivalent to an elevation shift of 500–800 or 700–1000 m for the two non-intervention emission scenarios. At the end of the century the number of snow days may be more than halved at an elevation of around 1500 m and only 0–2 snow days are predicted in the lowlands. The results for the intervention scenario reveal no differences for the first scenario period but clearly demonstrate a stabilization thereafter, comprising much lower snow cover reductions towards the end of the century (ca. 30 % instead of 70 %).

Projected cryospheric and hydrological impacts of 21st century climate change in the Ötztal Alps (Austria) simulated using a physically based approach

“…These projected changes in snow coverage generally show similar patterns to studies for other Alpine sites (e.g., Beniston et al, 2003;Marty et al, 2017;Schmucki et al, 2015a;Steger et al, 2012), however with a tendency to lower relative decreases in average snow amounts. This is likely due to the comparatively strong increases in winter precipitation especially for the warmest (RCP8.5) scenario (Fig.…”

“…7). A comprehensive study recently done for Switzerland (Marty et al, 2017) for example projected more dramatic changes in snow amounts especially in high elevations (> 3000 m a.s.l.) until the end of the century for the A2 scenario (similar warming as in the RCP8.5 scenario), however projecting only very minor winter precipitation increases.…”

“…Rising temperatures are expected to result in more precipitation falling as rain rather than snow, a delayed onset of the snowcovered period, and an earlier onset of snowmelt, regardless of the considered emission scenarios (e.g., Frei et al, 2018;Gobiet et al, 2014;Marty et al, 2017). Possibly increasing winter precipitation amounts are expected to partly compensate for these temperature-induced effects of reduced average snowpack depths only in very high-elevated regions (e.g., Schmucki et al, 2015b).…”

The method ADAMONT v1.0 for statistical adjustment of climate projections applicable to energy balance land surface models

“…Such phenomena cannot be addressed using deltachange methods, which by definition apply fixed changes to an observed time series, conserving its statistical persistence properties and seasonality (e.g. Abegg et al, 2007;Hantel and Hirtl-Wielke, 2007;Schmucki et al, 2014;Marty et al, 2017) although those could evolve significantly under changed climate conditions.…”

Snowmobile impacts on snowpack physical and mechanical properties

“…Further, snowmaking (Spandre et al, 2016a) to supplement natural snow conditions and /or grooming (Fahey et al, 1999;Rixen et al, 2001;Spandre et al, 2016a) compacts the snowpack below it, and alters the underlying snowpack properties (Howard and Stull, 2014;Spandre et al, 2016a, b). Also, a changing climate will likely reduce the extent of snowcovered terrain and decrease the length of the winter recreation season (Lazar and Williams, 2008;Steiger, 2010;Dawson and Scott, 2013;Marke et al, 2015;Schmucki et al, 2015;Tercek and Rodman, 2016;Marty et al, 2017). In addition to possible effects from a changing climate, inter-annual variability of snowpack patterns can be large in Colorado (Fassnacht and Hultstrand, 2015;Fassnacht and Records, 2015;Fassnacht et al, 2017).…”