Geoscience Reference
In-Depth Information
Siachen glacier—site of an Indian and Pakistani military standoff for past
25 years—has shrunk to half its size.
Most of the studies attribute the retreat of the Himalayan glaciers to
rising air temperatures. The warming is much more pronounced in elevated
levels of the HKH (Hindu Kush-Himalaya) region (Tandong et al. 2009).
Impact of Climate Change on Water Supply
For energy-constrained economies in south Asia, the prospect of
diminishing river fl ows in the future and the possibility that energy potential
from hydropower may not be achieved, will have far reaching economic
consequences. Another reason of immediate concern is the danger of Glacier
Lake Outburst Flood (GLOF) which causes catastrophic discharges from
the failure of temporary glacial lakes dammed by loose earth (moraines)
materials formed by rapidly melting glacier ice. Observations indicate that
the frequency of GLOFs in the eastern Himalaya including Nepal, Sikkim,
Bhutan has increased during the last decade of 20th century and threatening
the very existence of many hydropower plants constructed recently on
Himalayan rivers.
The Indus and Sutlej Rivers originate in the ice fi elds of the western
Tibetan plateau, an area experiencing exceptionally high warming—1.8ºC
or 0.3ºC per decade, over the past 50 years, twice the rate of observed global
warming. The retreat in the Tibetan Plateau is driven by warming due to
the thickening of the global greenhouse gas blanket, but the rapidity of
glacier retreat during the past 25 years suggests additional warming may
be playing a critical role. Black soot in aerosol pollution can warm the
troposphere, enhancing surface melt. According to a report by the United
Nation Environment Program (www.unep.org), Integrated Assessment of
Black carbon and Tropospheric Ozone, the Himalayan and Tibetan plateaus
are regions where black carbon is likely to have profound impacts on the
ice fi elds and glacial melting.
Any change in upstream water supply or hydrology with changing
climate will have profound effect on millions of people in lower riparian
countries. Projections show that countries of South Asia will suffer from
water stress by 2050. Another area of concern in South Asia is extremely
limited water storage capacity in countries like Pakistan and India, for
example, less than 250 cubic meters of water per capita compared to more
than 5000 cubic meters per capita in countries like Australia and USA. The
lack of water storage capacities leaves the already vulnerable populations at
great risk of fl uctuations in water fl ows and changes in monsoon patterns.
Investments can be increased in natural and constructed water storage
systems.
Search WWH ::
Custom Search