Open Forum
New Delhi, 9 November
2022
COP27 & Glacier Melt
HIMALAYAN REGION IN FOCUS?
By Dhurjati Mukherjee
The COP27
has just begun in the Egyptian coastal city of Sharm el-Sheikh and the planet
is sending a distress signal. “Sea
level rise, glacier melt, torrential rains, heat waves -- and the deadly
disasters they cause -- have all accelerated,”warns the World Meteorological
Organisation in a report. While the world will debate as usual, reports have
clearly indicated that it is still nowhere near the scale and pace of emission
reductions required to put us on track toward a 1.5 degrees Celsius world.In
fact, there has been a warning that national governments need to strengthen
their climate action plans now and implement these in the next eight years,
which means that the onus would now be on emerging economies including India.
Dealing with
just one implication of global warming, it is in fitness of things to refer to
an article way back in 2013 in Nature where scientists cautioned that
rising temperatures in the Himalayas raise the threat of glacial lake outburst,
which is even more relevant today. Of the 8800 glacial lakes in the Himalayas, over
200 have been classified as dangerous. Himalayan nations were urged to build an
international network to monitor risks such as those from glacial lakes and
give early warning of hazards. Will the issue get the focus it deserves or get
lost in new pledges?
According to
available data, the Himalayan river basins cover an area of 2.75 million square
kilometers and have the largest irrigated area of 577,000 square kilometers,
and the world’s largest installed hydropower capacity of 26,432 MW. The melting
glaciers fulfill the water requirements of over a billion people of the region.
Obviously, these people will be affected when much of the glacier ice mass
melts and gradually stops supplying water to inland rivers. While Ganga and
Brahmaputra basins in India get a big chunk of their water from monsoons, the
situation is different for the Indus river, which is largely dependent on the
glaciers. However, changing rainfall patterns and rising global temperature
will affect the Ganga and Brahmaputra basins as well
As is
evident, majority of glaciers in the Himalayan region are melting due to rising
temperatures. Studies conducted by Geological Survey of India, Wadia Institute
of Himalayan Geology National Centre for Polar and Ocean Research and the
Indian Institute of Science have observed accelerated heterogeneous mass loss
in Himalayan glaciers. According to the Ministry of Earth Science, the mean
rate of Hind Kush Himalayan glaciers is around 15 metres per year which is
12.7-13.2 metres in Indus, 15.5-14.4 metres in Ganges and 20.2-19.7 in
Brahmaputra river basins.
The
landslides that have occurred in recent years have been triggered by a plethora
of natural and man-made factors such as heavy rainfall, earthquake, active
geological features, deforestation, large-scale land use changes among others. It
needs to be mentioned here that our investment in pro-active scientific
approaches -- natural hazard surveillance or flood forecasting -- is not
sufficient and technologically sound. In the absence of science policy-based
instruments, the destruction has been grave over the years.
However, in the first detailed inventory of glaciers at the
Alaknanda river basin, which contributed the maximum water to river Ganga,
scientists from IISc and IITs discovered a reduction of 59 sq km in the glacier area
over a period of almost 50 years, between 1968 and 2020. This meant that 8
percent of the total area of glaciers decreased. Scientists said regional
climate change was a big reason behind the development. This study of the river
basin, which took over two years to complete, was published in the Geocarto
International journal by Taylor & Francis. The average retreat
rate of glaciers in the basin was 11.75 m per annum.
The analysis of climatic parameters in the basin suggested
substantial evidence of deglaciation due to global warming, especially since
the winter temperature increased by 0.03 celsius per year between 1968 and
2020. The team of scientists studied almost all satellite imagery since 1968 meticulously
and found that though the area of the glaciers reduced in the river basin, the
number of glaciers increased from 98 to 116.
Scientists said the increase in numbers was a cause for
concern. Small portions of the glaciers were melting in a way that they would
not contribute water to the river and hence, there would be a “cascading effect”
on the water security of the people living downstream, they observed.
“They are melting faster and forming new water bodies such as lakes near the
glacier. If the glaciers melt faster in the future, these water bodies will get
added water and may overflow, causing destruction,” experts pointed out.
The seasonal
runoff from Himalayan glaciers provides different water services to about 800
million people for the purposes including irrigation, hydropower and drinking
water. As the glaciers melt unconventionally, it will eventually result in
water shortages. The greater runoff causes the rivers to flood. Glacier
melting, in some measure, affects the snowfall. A regular reduction in usual
winter snowfall leads to water shortage.
Thus, the
melting of these glaciers is undoubtedly a major cause of concern as it is
expected to have a massive impact on the water supply for the rivers. Experts
believe that continued melting will lead to change in glacier basin hydrology,
downstream water budget and impact on hydropower plants due to variation in
discharge, flash flood and sedimentation.
Excessive
melting doesn’t help water to mix with rainfall and groundwater, which is used
for crop irrigation and future supply during drought. The ratio of run-off to
rainfall determines both groundwater recharge and groundwater depletion.
Increased glacial melting would disturb this even distribution sustaining a
large population until now. It has been amply evident that the increased
melting of Himalayan glaciers has been causing flooding disasters and this is
expected to continue in the next few years. What would happen after that is the
Ganga and the Indus flowing with radically reduced pace may result in acute
water stress, mass migration, and unseen conflicts.
A study of
IIT Indore last year found that the total river runoff, glacier melt, and
seasonality of flow are set to increase until the 2050s, and then decrease,
with some exceptions. Researchers have called for greater focus on the problems
and to assess the current status and potential future changes of rivers for
sustainable water resource management for agriculture, hydropower, drinking,
sanitation, and hazard situations.
Climate
change and global warming are indeed dangerous phenomena, and its consequences
are severe for humans, affecting them in all possible ways. Even water, which
is the basis for human survival, has been affected in various ways due to the
ravages of nature and glacial melt is a key reason. There is thus an immediate
need to ensure that warming is controlled by checking emissions of greenhouse
gases to counter the disastrous effects of glacier melting. Experts and organisations
working in the field should come out with an action plan to control such
melting in the coming years.---INFA
(Copyright, India News & Feature
Alliance)
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