Global Change and Mountains: Consequences, Responses and Opportunities - Impact of Global Changes on Mountains: Responses and Adaptation - page 98

The Himalaya and Tibetan Plateau—the 'Water Tower of South Asia'
sustains livelihood and economy of approximately 200 million people. The
observed changes in headwater ecosystems are likely to have signifi cant
implications on water availability for the mountain as well as downstream
population (Stern et al. 2006). The continued melting of glaciers, snow and
ice cover will adversely affect the supply of water leading to severe water
crisis and potential confl icts in large part of the world. The Himalaya, for
example, constitutes headwaters of some of the largest trans-boundary
basins of planet (e.g., Amu Darya, Brahmaputra, Ganges, Indus, Irrawaddy,
Mekong, Salween, Tarim, Yangtze and Yellow River basins) that sustain one-
fourth global population dependent primarily on subsistence agriculture in
Pakistan, India, Nepal, Bhutan, China and Bangladesh (Table 4.3, 4.4 and
Fig. 4.3). Climate change has stressed hydrological regimes of Himalayan
headwaters through higher mean annual temperatures, melting of glaciers
and altered precipitation patterns causing substantial decrease in water
availability. This may increase the proportion of health, food and livelihood
of the insecure population in South Asia which includes some of the poorest
people of the world with access to less than 5% of the planet's freshwater
resources. This will have enormous regional implications for fundamental
human endeavours ranging from poverty alleviation to environmental
sustainability and climate change adaptation, and even to human security
Figure 4.3. Hindu Kush Himalaya and Tibetan Plateau with Major River Basins (Source:
ICIMOD).
Color image of this figure appears in the color plate section at the end of the topic.