Since industrialization, the anthropogenic influx of greenhouse gas emissions has significantly altered the climate system. By the end of the century, the global mean temperature is expected to increase by 1.4 to 5.8 ºC. The Himalayan glaciers are retreating at unprecedented rates ranging from 10 to 60 meters per year and many smaller glaciers (<0.2 sq km) have already disappeared (Bajracharya et al., 2008). Glacial retreat is only one aspect of climate change that will have deleterious effects on the Indian subcontinent. While we shall focus on glacial melting, we must acknowledge that there are a number of interconnected factors that increase India’s climate change-related risk exposure. For instance, rise in temperature affects evapo-transpiration levels and subsequently, agriculture, forestry and human activities especially in notably arid areas. Some projections propose a 10-15 per cent increase in monsoon precipitation and a simultaneous 5-25 percent decline in precipitation in central India, which is already drought-prone (Revi, 2010). It is important to address the coupling of these phenomena when devising adaptation and mitigation measures. Later, we will discuss strategies that could reduce the degree of damage of natural hazards on the livelihoods and traditional practices of people in India. Here, we will briefly address three of the first-order climate change impacts directly linked to glacial retreat.   

1) Glacial Lake Outburst Floods (GLOFs)

As the glaciers recede, the number and volume of potentially dangerous moraine-dammed lakes are increasing in the Himalayan region (Richardson et al., 2000). These marginal lakes form behind unstable glaciers or ice-cored moraines and could result in the sudden discharge of large volumes of water and debris due to the buildup of water pressure. These glacial lake outburst floods (GLOFs) are catastrophic, resulting in calamitous death tolls and injuries and the destruction of forests, agriculture and valuable mountain infrastructure. At least thirty two GLOF events have been recorded in the Himalayan region that resulted in detrimental effects including the heavy loss of lives and property. Increase in temperature will accelerate the retreat of the glaciers and consequently amplify GLOF events.

2) Limitation of Water Resources

In addition to the heightened threat posed by the formation of glacial lakes, the receding glaciers could result in adverse effects on water resources and society. The Himalayan cryosphere is the source of the major river systems in Asia and the lifeblood of 1.3 million people in the downstream valley (Bajracharya, 2008). The major river systems of the Indian subcontinent, namely Brahamaputra, Ganga and Indus which originate in the Himalayas, are especially vulnerable to climate change because of the substantial contribution from snow and glaciers into these river systems. The climate of the region is determined by the accumulation of runoff from glaciers and also monsoon precipitation during the summer. Since glaciers provide as much as 70% of Ganges’ inflow during the summer and 50-60% of the flow in other major rivers, alterations of the hydrological cycle and their impact on the climate system could result in water scarcity.

3) Sea-Level Rise

Data over the last century indicate an average sea-level rise (SLR) of less than one millimeter per year along the Indian coast. More recent data reveal a mean SLR of 2.5 millimeters per year since the 1950s (Aggarwal et al., 2001). Studies have indicated that Asian countries contain the largest fraction of the global Low Elevation Coastal Zone (LECZ) population. Sea Level rise is an alarming risk for a number of Indian coastal cities.