Glaciers and ice caps: Vulnerable water resources in a warming climate

The first decade of the 21st century was the warmest on record since the start of instrumental observations and rapid changes in various components of the cryosphere have been observed around the globe. The ongoing changes in glacial meltwater delivery due to climate warming are relatively well known in developed countries and detailed climate scenarios have been produced for the coming decades. The consequences of runoff change for the design and operation of important hydrological infrastructure have been investigated in the Nordic countries, where detailed records of glacier changes exist for the past several decades. Knowledge of the volume of ice stored in glaciers and ice caps is, however, still incomplete in many parts of the world and a clear picture of how climate impacts on the cryosphere will affect large populations in developing countries has not yet emerged. The situation in the mountainous region of Central Asia, now often referred to as the Third Pole, is briefly reviewed with emphasis on the need to reduce uncertainties in current knowledge of climatological conditions and glacier mass balance in that region.