Chapter 9 – What Future for Mountain Glaciers? Insights and Implications From Long-Term Monitoring in the Austrian Alps

Abstract The intensifying retreat of mountain glaciers is a highly visible indicator of global climate change and affects local geomorphological processes and hydrology. In the Austrian Alps, pictures and maps of glaciers date back to the early 17th century. Regular length change surveys started in 1891, glacier runoff measurements in 1897, and mass balance data in 1953. Glacier inventories have mapped area changes of all glaciers since the Little Ice Age. Long time series and high data density allow a discussion of the representativeness of monitored glaciers, supporting the setup of measurements in other mountain regions. Length changes are being measured for about 10% of all glaciers, all other parameters on less than 1%. Each parameter captures different aspects of recession, for example inventories and fluctuations reflect spatial, mass balance, and runoff temporal variabilities. The representativity of measured glaciers for the total sample changes over time. Glacier disintegration, debris cover, and proglacial lakes are challenging for future monitoring. A large enough number of monitoring areas is needed to ensure the supply of reliable data for developing local adaptation measures and process models for other regions in the world.