Climate change has a substantial impact on snow cover in mountain regions, often leading to shorter snow cover duration, later snow cover onset, earlier snow melt, higher snow line elevations, less water stored in the snowpack, and subsequent effects on flora, fauna, tourism, hydropower generation, and agriculture. It is essential to understand these developments and dynamics to be able to anticipate these effects and potentially mitigate their impact on society and biodiversity. The Landsat satellites provide an ideal collection of high-resolution remote sensing datasets collected since the early 1980s, which allow for a detailed analysis of the long-term trends of snow cover in mountain regions worldwide. Recording in intervals of up to 16 days and being affected by cloud cover makes an extensive processing and aggregating necessary in order to retrieve continuous time series ready for trend analyses and predictions of future developments. The first part of the presentation will therefore focus on the methodology which was developed and applied to the Landsat archives to extract the long-term trends and predictions.
The second part of the presentation will include detailed results for the European Alps, the Pyrenees, and the Andes Mountains around Santiago de Chile. After analyzing 40 years of snow cover data derived from all available Landsat satellites, the catchments within almost all investigated mountain ranges depict negative trends, with snow line elevations receding up to 20 m per year. Predictions of potential future snow line developments have been calculated based on several methods and will be presented as well.