Global Change and Mountains: Consequences, Responses and Opportunities - Impact of Global Changes on Mountains: Responses and Adaptation - page 96

intensifi ed retreat of Alpine glaciers has been observed during the previous
century (Borsdorf et al. 2010). The Alpine glaciers have reduced by nearly
35% between 1850 and the 1970s, and as much as by 22% by 2000 (UNEP-
WGMS 2008). The volume of glaciers in Canadian Rockies has decreased a
minimum of 25% during the last century (Luckman and Kavanagh 2000).
In the world's highest and largest mountain system—Himalayas, the rate
of retreat of glaciers has been relatively faster than the world average and
they are thinning at the magnitude of 0.3-1 m/year (Dyurgerov and Meier
2005). Further, it was investigated that the Himalayan glaciers are losing
mass faster than European glaciers but slower than those in Alaska (Inman
2010). The rate of retreat of the Gangotri—the largest glacier of Himalaya
—has been three times higher than the rate at which it melted during the
preceding 200 years (Bhandari and Nijampurkar 1988, Tiwari 1972, Tiwari
and Jangpangi 1962, Mukhophadayay 2006, ICIMOD 2007, IPCC 2007a,b,
Rawat 2009, Srivastava 2003). In the Nepal Himalaya, a large number of
glaciers have been observed to be receding rapidly (Seko et al. 1998, Kadota
et al. 2000, Fujita et al. 2001). The study indicated that 6% glaciers in the
headwaters of Tamor and Dudh Koshi basins in the Nepal Himalaya have
decreased during 1970-2000 (Ouyang 2012). As much as 82% glaciers in
western China have receded during the last half century (Liu et al. 2006,
Kang et al. 2010) and as much as 5.5% glaciers receded during 1980-2005
(Ouyang 2012). Further, the area under glaciers in the Tibetan Plateau has
decreased by about 11.5% over the last 40 years (CNCCC 2007). Similar
trends in the responses of glaciers and snow-packed areas have been
observed in South African mountains where about 85% of the total ice
volume of the plateau glaciers of Mount Kilimanjaro in Africa vanished
between 1912 and 2000 (Thompson et al. 2009). In general, de-glaciation
is accelerating in mountains, and consequently, most snow and ice caps
across the world are shrinking at alarming rates. However, exceptionally
and interestingly, some of the high altitude glaciers in the Karakorom ranges
in Asia have been found either advancing or stable as in the 1970s many
of these glaciers showed evidence of short-term thickening and expansion
(Hewitt et al. 1989). Out of 42 studied glaciers in Karakoram region, 58% are
either advancing or stable and 42% retreating (Scherler et al. 2011, Hewitt
2005). Inman (2010) observed that the remote glaciers of the Himalayan
mountains have been a subject of much controversy, but without adequate
research. Out of about 12000 to 15000 glaciers in the Himalaya and nearly
5000 in Karakorum, very few have so far been monitored on the ground.
However, he maintains that Himalayan glaciers have been losing mass,
with noticeably greater loss in the past decade (Inman 2010). In all other
mountain regions including the Himalaya, Hindukush, West Kunlun Shan,
the glaciers are mostly retreating, and the study has observed that the debris
cover has a signifi cant infl uence on glacier terminus dynamics (Scherler et al.