Central Asian Journal of Water Research (2019) 5(2): 44-63 © The Author(s) 2019. ISSN: 2522-9060 Published by Kazakh-German University, Almaty / Kazakhstan Vanishing high-mountain ice causing hydrological challenges at global to local scales: An overview with notes on Central Asia Wilfried Haeberli Geography Department, University of Zurich, Switzerland Email: wilfried.haeberli@geo.uzh.ch Received: 22 February 2019; Received in revised form: 21 November 2019; Accepted: 07 December 2019; Published online: 10 December 2019. doi: 10.29258/CAJWR/2019-R1.v5-2/44-63eng Abstract Glaciers and permafrost react strongly to atmospheric temperature rise. As a consequence, icy mid-latitude high- mountain environments including mountain ranges in Central Asia undergo rapid changes. Continuation of these changes must at least in part be considered unavoidable and the resulting impacts on the water cycle will be irreversible for generations to come. Primary hydrological challenges relate to sea level rise at global scale, to water supply from river discharge at continental to regional scale, and to the formation of new lakes with related options concerning hydropower, water resources or tourism and with their risks related to impact and flood waves at regional to local scales. International scientific cooperation, the use of new observational technologies and of enhanced modelling capacities together with comprehensive system analyses can form the knowledge basis for participative planning and the search for integrative solutions in adaptation strategies. Slowing down global warming by reducing greenhouse gas emissions will help assuring the necessary time for this difficult task. The present contribution is based on a keynote presentation at the 2018 International Symposium on Water and Land Resources in Central Asia (CAWa). It reviews the current international literature on the topic in view of developing the necessary knowledge basis, including aspects related to Central Asia. Keywords: glaciers, permafrost, water resources, climate change, high mountains Paper type: Literature review 1. Introduction The largest perennial ice masses in high mountains exist in the form of surface ice (glaciers) and subsurface ice (permafrost). These ice masses are exposed to rapid global warming at a rate, which in high mountains is considerably faster than the global mean (elevation dependent warming) (MRI 2015). Continuation of such atmospheric temperature rise causes both ice components to reduce and even to vanish in many places and over extended periods of time. As these ice masses are part of the water cycle, their shrinking and potential disappearance has hydrological consequences far beyond high mountains. Understanding, anticipating and dealing with such hydrological consequences constitutes scientific as well as political and