Geoscience Reference
In-Depth Information
population growth, economies, land-use change and urbanization. Climate
change is also likely to alter ecosystem composition, structure and function;
biodiversity, loss of soil carbon and, groundwater recharge (Xu et al. 2008).
Biodiversity is crucial in ensuring food security, nutrition, access to water
and the overall sustainability of the region, and closely linked to climate
change. Ten to thirty percent of the region's faunal species are under threat
of extinction (World Bank 2009b, UNEP 2012b).
Some projections on the future Himalayan glaciers may have serious
implication on water resources and food security. Based on a projected
estimate glacier area in 2050, it is thought that declining water availability
will eventually threaten some 70 million people with food security (Table
10.1) (Eriksson et al. 2009). Expected impacts of climate change are; as
much as 20% lower yield of major crops, an anticipated a 15-30% decline
in the productivity of most cereals and rice across South Asia. Due to
cumulative effect of water scarcity, glacial retreat, change in monsoon,
fl ooding, desertifi cation, pollution and soil erosion, a massive reduction in
the production of rice, wheat, maize and fi sh will be felt. With the increasing
water demand due to population growth and economic development,
the agricultural sector will continue to be the major consumer of water in
the HKH region. China's 65% of water for agricultural consumption will
decline to 55% by 2030. In India, almost 90% agricultural uses of water will
decline to 70-75% by 2050. Moreover, depletion of water due to pollution
and losses caused by ineffi cient management is also considerable. In the
Yellow River, 34% of the river water is unfi t for drinking, aquaculture, and
agriculture and pollution of the tributaries of Yangtze River extent to 30%.
In India, the Yamuna River, the main tributary of the Ganges is polluted
up to of 50% (SFG 2010).
About 90% of rice is grown and consumed in Asia (Gujja and
Thiyagarajan 2009). Per capita water availability in India was 1730 cubic
meter per person per year in 2006, close to World Bank's 'water stressed'
level which is 1700, and expected to decline to 1240 by 2030 which is
extremely close to becoming the World Bank's 'water scare' level (1000
cubic meters). India's water utilization rate is 59%. This is already crossing
the threshold standard of 40% (i.e., without providing natural capacity to
recharge adequately) (SFG 2010). Most of the harvest comes from irrigated
agricultural land around the Ganges (two-third of Delhi's water comes
from the Ganges), and the Yamuna. The Yangtze irrigates more than half of
China's rice (Larmer 2010), and the Yellow River basins, have experienced
slowdown in the growth rates of rice yields since the mid-1980s. The Yellow
and Ganges Rivers are expected to lose between 15 to 30% water due to
glacier depletion and will turn into seasonal rivers by the second half of the
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