Melting Permafrost in the Alps
Above 2,300 meters, permafrost holds the Alps together like an invisible glue. The cross-border FROST.INI project highlights the danger of its decline for ski resorts and mountain roads, but also demonstrates how Alpine regions can prepare themselves.
Mountain permafrost, which is widespread in the Alps above altitudes of 2,300 to 2,500 meters, forms a fundamental structural element for the stability of mountain slopes and high-alpine infrastructure. However, global warming is accelerating its degradation. This leads to a thickening of the so-called active layer (thaw layer), greater slope instability, and an increase in landslides, rockfalls, and ground deformations.
To investigate these developments, the Interreg project FROST.INI adopts an integrated and comparative approach. It examines representative pilot sites along a broad altitudinal and lithological gradient – from Casera Razzo (1,880 m) across the glacial areas of the Kitzsteinhorn to the Hohe Tauern region and the Großglockner (3,798 m). The analyses combine geophysical surveys, climate and monitoring data, and geomorphological observations with socioeconomic evaluations. The latter take into account factors such as tourist pressure, seasonality, infrastructure, accessibility, and control systems.
The project results reveal three main levels of sensitivity in the Alps:
- Lower-altitude sites with so-called relict permafrost and attenuated dynamics.
- Mid-to-high altitude sites with thawing, active permafrost and direct impacts on ski resorts and infrastructure.
- High-alpine environments with still widespread permafrost, but increasing instability linked to glacial retreat and the ongoing warming trend.
A direct comparison between remote areas and large ski resorts makes it clear that the exposure, vulnerability, and adaptive capacity of individual regions are highly heterogeneous.
With these findings, FROST.INI provides a sound scientific foundation for differentiated risk management strategies. The overarching goal is to strengthen the resilience of Alpine regions in the context of accelerating climate change. This is to be achieved through targeted monitoring, adaptive spatial planning, and the corresponding adjustment of infrastructure.