Mountain permafrost and climatic change

Abstract Perennially frozen slopes occur in many mountain ranges of the world. Ice‐rich debris or morainic material especially exist under subcontinental to continental‐type climatic conditions with elevated glacier equilibrium lines. Such supersaturated mountain permafrost exhibits pronounced creep movements, thereby forming large numbers of rock glaciers. Reconstructions of late‐glacial palaeotemperature and palaeoprecipitation using combined glacier/permafrost studies reveal dramatic changes in permafrost belts and in the periglacial environments of mountain areas during the pronounced late‐glacial warming. As a consequence of atmospheric warming during the first half of the twentieth century, the lower boundary of mountain permafrost distribution in various mountain ranges such as the Alps may have shifted in altitude, causing local degradation of formerly frozen slopes. Continued or even accelerated future warming is likely to induce further retreat and degradation of high‐altitude permafrost.