Adaptation to Climate Change in Mountain Regions: Global Significance of Marginal Places - Impact of Global Changes on Mountains: Responses and Adaptation - page 147

towers due to their water storage capacities in glaciers, permafrost, snow,
soil and groundwater (Liniger et al. 1998). The 10 largest Asian rivers,
namely the Amu Darya, Indus, Ganges, Brahmaputra, Irrawaddy, Salween,
Mekong, Yangtze, Yellow and Tarim all originate in the Himalaya. They
provide water for approximately 1.3 billion people (Xu et al. 2009). Melting
snow and ice contribute about 70% of summer fl ow in the main Ganges,
Indus, Tarim, and Kabul Rivers during the shoulder seasons, that is before
and after precipitation from the summer monsoon (Singh et al. 2006, Barnett
et al. 2005). The contribution of glacial melt to fl ow in the Inner Asian rivers
is even greater (Yao et al. 2004, Xu et al. 2004, Chen et al. 2006). Indus River
irrigation systems in Pakistan depend on snowmelt and glacial melt from
the eastern Hindu Kush, Karakoram, and western Himalayas for about 50%
of total runoff (Winiger et al. 2005). In western China, about 12% of total
discharge is glacial melt runoff, providing water for 25% of the total Chinese
population in the dry season (Li et al. 2008, Xu 2008). The Alps supply a
signifi cant proportion of water for the population of Europe (Baumgartner
et al. 1983, Braun et al. 2000). This water means freshwater, irrigation
and hydropower. The energy aspect of mountain waters based on water
abundance and topography must not be underestimated in comparison to
freshwater and irrigation uses. Hydropower constitutes a signifi cant part of
the energy supply in many mountain regions, i.e., hydropower covers about
60% of the Austrian and nearly 100% of the energy demand of Norway.
Worldwide mountains are the source for 50% of all rivers (Beniston 2003).
Much of the inter- and intra-annual variation of discharge is compensated by
discharge from mountains. In semi-arid areas mountain discharge accounts
for 50-90%, in extreme cases (e.g., Nile, Colorado) for more than 95% of the
total river discharge (Viviroli et al. 2007).
A direct knock-on effect of glacier retreat and thawing of permafrost is
the resultant destabilization of mountain slopes and thus endangerment of
life and infrastructure in the valleys (Stoffel et al. 2005) while its cascading
effects precipitate via river runoff, water availability and hazards, pollination
and phenology, prey-predator relations, endemism and extinction, shifting
tree-line, ecosystem composition to society, economy and culture. Carey et
al. (2012) point out that “social confl icts in response to real and perceived
water shortages have already emerged in Peru's most glaciated mountain
range, the Cordillera Blanca”.
The ecosystem services that mountains provide go beyond water
and include hydropower, fl ood control, mining and tourism. For many
exists a direct linkage with adjacent lowlands in catchments systems and
for their extractive resources exists global demand (Löffl er 2004, Viviroli
and Weingartner 2004). It has been estimated that all together mountains
provide resources (Viviroli and Weingartner 2004) and ecosystem services
to about half of humanity (Becker and Bugmann 2001). It is this central role