Climate change is causing significant loss of glaciers in high mountain areas of the world. Although glacier systems show a great amount of inherent complexity and variation, there is clear evidence indicating glaciers are retreating. A number of noticeable impacts have already been documented. The most widely reported retreat is the reduction in size (length, area and volume) of glaciers due to the rapid melting. This in turn has short and long-term implications on water storage in the river basins and in various ways is affecting the livelihood of people, flora and fauna. In addition, the continuous recession of glaciers has been inducing fast reduction in their size and many of them (<1 Km2) may eventually disappear. The reduction in size of the glaciers is also anticipated to have significant impacts on geo-environmental hazards, like snow/ice avalanches, glacial lake outburst floods (GLOF), flash floods, landslides and debris flows. The direct consequences of such processes will also be exaggerated by a variety of direct/indirect effects in mountain ecology.
Glaciers are sensitive to the temperature and precipitation changes that accompany climate change, the rate of their retreat or growth can serve as an indicator of regional and global climate change. In addition, glaciers and snow cover are key components of mountain hydrology and its adjoining areas as well as climate change. Measuring changes in snow cover extent and mass volume of glaciers on an appropriate time scale is a direct way of determining the effect of climate change. Enhanced recession rates of glaciers reported during the recent years has initiated wide spread discussions, especially in context to global warming and its effects on glacier systems. However, the rate of recession and amount of volume change are different from other mountain glaciers of the world. This is mainly due to different magnitudes of climate and topographic conditions. European Alps have lost about 30 to 40 per cent of their surface area and about half of their volume since 1850 (Haeberli and Beniston, 1998). Similarly, glaciers in Central Asian regions have been reported to be rapidly retreating since 1950 (Fitzharris, 1996; Meier, 1998). A study of 466 glaciers in Himachal Himalaya also shows that glaciers are receding like the rest of the glaciers in the world (Kulkarni et al., 2007).
This study attempts to investigate change of glaciers for the period from 1962 to 2012 in the Indian Himalayas. The morphological and anatomical changes have been correlated with temporal affinity in relation to length, area and mass/ volume of the glacier. The study reveals that most of the Himalayan glaciers are retreating with an average annual rate of 10 - 20 m. The continuous recession of the glaciers in length, area and mass/ volume are attributed to climatic influence and play an important role in the processes of nourishment and reduction of the glacier.