Long-term, large-scale monitoring using multiple observation techniques is necessary to establish historic glacier distributions and their changes over time. Such observations – ranging from seasonal mass balances of individual glaciers to decadal volume changes within entire regions – are vital to understanding underlying processes and projecting future changes. We thus invite contributions targeting all aspects of glacier monitoring (e.g., of area, length, volume, temperature, velocity, mass), as well as method comparisons and uncertainty assessments.