Can Global Warming Make The Ganges Run Dry?
Dr Nachiketa Das
Director, NRI-Enviro-Geo-Tech- Australia, Sydney; School of Kaya Yoga,
www.kayayoga.net
(First published on September 6, 2008 on
www.hotnhitnews.com.)
Global warming, now in 2008, is real, and upon us. How will global
warming affect the rivers in India; will they all dry up? Can the
holy
Ganges, the river that has shaped and sustained Indian civilisation
through the ages, who we Indians revere as the life-giving mother,
run
dry! Many climate experts and environmentalists, in the last ten
years,
have been making dire predictions of the Ganges becoming seasonal.
Some
doomsayers have even gone to the extent of boldly predicting the
river
to be ephemeral by the year 2035, which is barely a generation away!
Is
it really possible that the Ganges will run dry by 2035! Is this
calamity an inevitability that should be accepted as fait accompli,
or
is there anything we, the people of India, collectively can do to
save
the holy Mother Ganges from extinction. This profound issue demands
examination, and I propose to engage my readers in a serious debate.
Source of the Ganges
The Ganges originates from Gangotri glacier, which is one of the
largest valley glaciers located in western Himalayas. 30.2 km long
and
0.5 to 2.5 km wide Gangotri lies recumbent at the altitudes between
4,120 and 7,000 m above sea level. This glacier originates in a
cirque,
which is a natural amphitheatre like space at the base of a mountain,
immediately below the locally highest Chaukhamba peak, and is fed by
several tributary valley glaciers. The total area occupied by this
glacier complex (in 2001) is 260 square km, which contains 40 cubic
km
of ice (in 1999). During a 60 year period between 1936 and 1996,
Gangotri has receded by as much as 1,147 m, 850 m of which happened
during a 25 year period between 1971 and 1996. In a three year period
between 1996 and 1999 Gangotri retreated by 76 m. When this result is
contrasted with the 2,000 m retreat over the last 200 years, the
significantly accelerated rate of retreat becomes obvious. Available
data show that the rate of retreat in 1971 was 19 m per year, which
has
now accelerated to 34 m in 2007. Having observed these rates of
retreat
some experts and environmentalists have speculated that due to global
warming Gangotri glacier may completely disappear by 2035. If that
happens, they argue that the Ganges will cease to flow during the
summer months, and will drain only the monsoonal rains thus becoming
seasonal. I would like to record here that while Gangotri is
receding,
a large number of glaciers further west are growing in size and
volume!
Let us investigate the issue further.
Global warming is not uniform
Global warming does not mean uniform amount of warming at each and
every place on the globe. Although vast majority of the places on
this
earth will become hotter due to global warming, however strange it
may
seem, certain parts will in fact become cooler. Moreover, global
warming does not mean that the earth will uniformly dry up, or for
that
matter there will be no rains. Although bulk of the continental
landmass will become much drier, quite paradoxically again, some
places
will actually become wetter and receive much more rainfall. In the
following section I will present discussions to convince my readers
of
my assertions that one: some places will become cooler, and two: some
places will receive much more precipitation, due to global warming.
Let
me start my discussion to explain cooling, which can occur, say for
instance, at a place in higher latitudes currently kept warm by the
Gulf Stream.
The Gulf Stream
The Gulf Stream is a vast oceanic current that carries warm waters
from
the tropics to the temperate regions of northern Europe and North
America. This ocean current originates in the Gulf of Mexico, flows
past the east coast of the USA and Newfoundland in Canada, and then
crosses the Atlantic Ocean. It then branches into two, with the
northern stream moving to northern Europe. The Gulf Stream is about
80
to 150 km wide and a 1,000 m deep river of sea that transports 1.4
petawatts (1 petawatt is 1,000 million megawatts) of heat, which is
equivalent to almost 100 times the current energy demand of the
entire
world. Around Cape Hatteras on the coast of North Carolina in the US,
the Gulf Stream transports water at the rate of 80 million cubic
meter
per second, and is much bigger than any river system of the world; in
fact the combined release of all the waters from all the rivers
flowing
into the Atlantic is only 0.6 million cubic meter per second.
As the Gulf Stream proceeds north, the warm waters undergo cooling
due
to evaporation, and the evaporative loss makes the waters heavier due
to increased salinity. By the time it reaches North Atlantic, its
saltier heavier and denser waters sink in the relatively less salty
and
less dense waters, and reverses its direction of travel and embarks
on
a southward journey.
The Gulf Stream has significant localised effects on the climate of
the
east coast of Florida and Massachusetts in the US; and the west coast
of Britain, which is a good few degrees warmer than the east coast.
The
warming effect of the Gulf Stream is most dramatic in the western
islands of Scotland, so much so that the small township of Plockton
(latitude 57.33oN) that is located east of the Isle of Skye, has a
mild
climate that allows sub-tropical cabbage-palm-trees to grow. The
local
climate in Plockton in the absence of the Gulf Stream would be
freezing
cold as latitudinally it lies further north of Moscow (latitude
55.45oN) by almost two degrees.
Due to global warming, there is every possibility that the Gulf
Stream
may change course or it may lose its strength. In fact in November
2004, it completely stopped for full ten days, and there are reports
saying that in the last 50 years (since 1957) its deep return flow
has
weakened by as much as 30%. Any change in the characteristics of the
Gulf Stream, would cause significant localised cooling in Scandinavia
and Britain. At a time of global warming, the western islands of
Scotland will experience substantial cooling.
This very logic that global warming is not uniform is also applicable
to Himalayan environment, where in certain pockets the glaciers
instead
of disappearing due to global warming, may start to grow due to a
combination of reasons. Unlike the Scottish islands, the Himalayas,
however, are not influenced by the Gulf Stream, but by an equally
powerful agent, monsoon, which is discussed below.
Monsoon and its effect on Himalayan environment
Himalayan mountain system is a vast 2,400 km long arc sprawling from
the west to the east. Width of this range varies from 400 km in
Kashmir
in the west to 150 km in Arunachal Pradesh in the east. The Himalayas
consist of three parallel ranges, the northern most being the Great
or
High Himalayas, with an average height of 6,100 m. This is where more
than a hundred mountains that exceed 7,200 m in height exist. The
Great
Himalayas act as a massive barrier that arrests the South West or the
summer monsoon, which starts around June and continues till
September,
and the North East or the winter monsoon, and prevents their escape
to
northern Asia.
In hot summer months, intense incoming solar radiation (insolation)
significantly heats up the Great Indian Desert of Thar in Rajasthan
and
adjoining semi-arid regions of Indian landmass causing a low pressure
over north and central India. Waters of the Indian Ocean also
experience similar heating that causes a large scale evaporation
leading to the production of moisture laden winds. These winds flow
in
to fill up the vacuum created by the low pressure, and proceed north
until they reach the Himalayas, which as mentioned earlier act as a
huge wall, forcing the winds to rise higher. At high altitudes these
moist winds cool and precipitation of rain and or snow occurs. The
north-eastern part of India, where Cherrapunji is, receives abundant
rainfall.
In a slight diversion from the main course of this article, I would
like to record here that the name Cherrapunji, which was the
anglicised
version of Sohra in the native lingo, has just been reverted back to
the original by the State Government of Meghalaya. Sohra receives the
highest rainfall in the world of about 1,200 cm per year, and also
holds two unique records. The first record is the maximum rainfall in
the world of 2,299 cm in a single year (between August 1860 and July
1861); and the second, is for the maximum amount of rainfall of 930
cm
in a single month in July 1861.
Now let us go back to the movement of the monsoon clouds, which then
turn west and move along and over the Himalayas, in the direction of
Kashmir, causing widespread rains. Intensity of the rainfall,
however,
decreases towards the west. The Himalayas also receive a significant
amount of precipitation from the North East or the retreating monsoon
of the winter months.
The South West Monsoon like the Gulf Stream is a vast natural system
of
transport of energy and water, and carries 1.2 petawatts (1,200
million
megawatts) of heat energy. The monsoon system, both South West and
North East combined, transports about 12,000 billion cubic meter of
water vapour over the Indian landmass annually, a third of which
precipitates as rain and snow. I will present a small calculation
using
some round figures to demonstrate the enormity of the volume of
precipitation India receives due to the monsoon. Let me start with
the
annual average rainfall of India, which is about 117 cm (1.17 meter)
over a landmass of 3.3 million square km. The amount of rainwater the
landmass thus receives is about 3,860 billion cubic meter (1.17 m X
3.3
million km2) or say 4,000 billion cubic meter (4,000 km3).
Over the millennia these monsoonal precipitations have created the
vast
glacial environment in the Himalayas that now hosts 18,065 glaciers
spread over a total area of 34,659 square km containing a total
volume
of 3,734 cubic km of ice. The vast majority of these glaciers (9,449)
exist in the central Himalayas. The western Himalayas host 5,648
glaciers and the rest (2,968) occur in the eastern Himalayas. I want
my
readers to realise that the Himalayas have the largest concentration
of
glaciers outside the polar ice caps, and provide about 500 billion
cubic meter (500 km3) of water annually. Unfortunately, at present,
67%
of these glaciers are receding, and the retreat is being attributed
exclusively to global warming by many. In the following section I
demonstrate that global warming will make the monsoon system more
vigorous yet erratic, which in turn will affect the general
environment
of the Himalayas to a significant extent.
Global warming and erratic monsoon
This year the onset of the South West Monsoon on the Indian landmass
was almost a week early, and the arrival at New Delhi was two weeks
ahead of schedule. The early arrival at Delhi in 2008 broke a 108
year
old record. This new record may create the impression that early
arrival of the South West Monsoon may become the norm. This
observation
may not be correct though, as in the last few years the onset of
monsoon has been late too. Early or late, one fact that is obvious is
that monsoon has become erratic, and global warming will make the
erratic behaviour even worse. The duration of the monsoon season will
also vary; it may become shorter or even longer.
As stated earlier, solar heating of sea water generates monsoon.
Because of global warming, the surface water temperature of the
Arabian
Sea, the Bay of Bengal and the Indian Ocean that generate the South
West as well as the North East Monsoons, will increase, which in turn
will make monsoon more intense. I offer a simple analogy of a kettle
full of water on a stove to explain the rise in intensity of the
monsoon system. When the kettle is heated gently the water boils
slowly
and does not produce much steam. On the other hand if the kettle is
heated strongly, that is the kettle receives a lot more heat, the
water
boils vigorously and generates copious amounts of vapour. Likewise
hotter sea surface will generate more intense monsoon than a cooler
sea.
A more intense monsoon system will not only raise the peak
wind-speeds
of the storms but also increase their frequency. In the last ten
years
we have already seen some very severe storms and downpours in India,
Bangladesh and Myanmar. I will mention an example from each of the
three above mentioned countries. The super cyclone of 29, 30 and 31
October 1999 that devastated the state of Orissa in the east coast of
India had wind-speeds over 260 km per hour perhaps reaching as high
as
300 km. Widespread torrential rains that accompanied this category 5
cyclone, poured anywhere between 60 to 80 cm of rain over the
Mahanadi
basin in the three day period. The maximum rainfall during the storm
was even higher at 95 cm recorded in Bhadrak district of Orissa. I
want
my readers to appreciate the scale of this almost one meter rainfall
in
three days, which is higher than average annual rainfall of many
parts,
even many countries of the world.
The super cyclone caused a storm surge of about 6 m above the
astronomical tide recorded at Paradip port on the 29th of October
1999,
which was probably 8 m at some other coastal locations that travelled
up to 20 km inland. The lethal combination of the cyclone, flooding
and
the storm surge killed over 10,000 people, 400,000 heads of cattle, 2
million domestic animals, and uprooted or broke 90 million trees. A
vast majority of these trees had stood tall for generations, and some
for centuries. Destroyed were crops over a land area of 17,110 square
km, and 275,000 homes that created 1.67 million homeless. The damages
by this super cyclone also known as the Paradip cyclone were simply
unprecedented in the history of Orissa that made at least 5 million
farmers lose their livelihood. This cyclone affected Myanmar too.
Bangladesh has seen many devastating cyclones. The latest very severe
cyclonic storm that affected Bangladesh was only last year, on the
15th
of November 2007 to be precise. This category 5 cyclone, Sidr
attained
peak wind-speeds of 260 km per hour, and caused a storm surge of over
5
m that inundated low lying coastal regions. Despite massive
evacuations
of the order of 2 million people, the cyclone, heavy rains and the
storm surge united to cause 10,000 fatalities. Cyclone Sidr of 2007
is
generally considered to be the strongest to have stormed Bangladesh
since 1991 cyclone that had caused over 143,000 fatalities. Cyclone
Sidr utterly destroyed the mangrove forests of entire one quarter of
the vast Sunderbans that marks the very end of the Ganges-Brahmaputra
delta, and is a world heritage site. The devastation was such that
the
forest will take at least 40 years to regenerate. This cyclone
affected
the Indian states of West Bengal and Orissa too.
On the 2nd of May 2008, category 4 tropical cyclone Nargis that
ravaged
Myanmar reached peak wind-speeds of 215 km per hour and seriously
damaged the capital city Yangon. Vast areas of the low-lying Irrawady
delta were inundated by a combination of torrential downpours and a
3.5
m tidal surge that caused at least 146,000 fatalities. Such severe
cyclones will become even more intense and certainly much more
frequent, due to global warming. These intense cyclones are evidences
of the intensification of the monsoon system.
Due to the more intense monsoons, recent years have seen far heavier
rainfalls practically over the entire eastern and northern parts of
India, and Bangladesh. Last year serious floods played havoc with the
lives and properties of hundreds of millions of people in virtually
all
the states of eastern India. This year, as I write this article,
eastern India has received torrential rainfalls, and vast areas in
the
states of Orissa and Bengal have already been severely flooded
rendering millions homeless. A few days ago, on the 24th of August
2008, following heavy rains in Himalayan foot-hills in eastern Nepal,
the Kosi river breached its bank and opened a channel in the
adjoining
north Bihar, it had abandoned over 200 years ago. The initial 3 km
wide
breach grew at the rate of another 200 m per day. The ensuing
inundation instantly affected over two million people, eventually
making three million homeless. Initial reports speak of hundreds of
deaths, and the fatalities are bound to rise.
Heavier rains in Rajasthan and at Tehri
I hope I have convinced my readers that monsoon will become more
intense and erratic in the future due to global warming. The more
vigorous monsoon will carry more water vapour, travel much faster and
will generally lead to higher precipitations on the landmass of
India.
The monsoon clouds moreover, will penetrate deeper into the
Himalayas,
scale higher altitudes and probably cause significantly higher
amounts
of precipitation. The monsoon system might have already started
penetrating deeper into the Himalayas and north-western India,
evident
from significantly higher rainfall in the last ten years in the north
western most state of India, Rajasthan, which has been a desert
state,
and constitutes the last stop of the South West Monsoon before
dissipation. In July 2003 the South West Monsoon caused heavy
downpours
in Rajasthan leading to 9 deaths. The maximum recorded rainfall in a
matter of a couple of days in July 2003 was 7 cm, which is very high
and unusual for the desert state. In July 2007 rainfalls were heavy
too
due to a vigorous South West Monsoon. The state of Rajasthan as a
whole
as of the 14th of August 2008 had received an average rainfall of 433
mm as against 342 mm in the same period of the previous year. 9
districts of the state recorded abnormal (60% more than average)
rainfall.
Further evidence of more vigorous monsoon penetrating deeper in to
the
Himalayas could be gleaned from the reports of regularly higher
rainfall of the past few years at the sprawling body of water of
Tehri
reservoir, which is barely 50 km from Gangotri glacier. I must,
however, state that Tehri Dam is situated at an altitude of only 770
m
above sea level where as Gangotri’s lowest point is at 4,000 m.
Growth
of glaciers in the western most Himalaya, also provide some very
interesting evidence of vigorous monsoon, discussed below.
Growth of glaciers in the western most Himalayas
The Karakoram Range in the western Himalayas that is over 500 km
further north-west of Gangotri plays host to a number of glaciers.
The
most prominent glacier in the Karakoram is the 74 km long Siachen,
which is not only the largest Himalayan glacier but also the largest
in
the world outside of the polar-regions. The head of this high
altitude
valley glacier lies at 5,753 m above sea level at its source at
Indira
Col in the north, and its snout lies at an elevation of 3,620 m in
the
south. A glaciologist Mr VK Raina in his article published in the
Journal of the Geological Society of India in 2007 has recorded that
Siachen glacier ‘along its snout front has been in a rest mode’,
which
in plain language means that the glacier is not retreating. During my
tenure with the Department of Science and Technology of the
Government
of India, I had the pleasure of interacting with Mr Raina, and I am
quite willing to accept his observation on Siachen. Moreover, I would
like to add that the neighbouring 58 km long Baltoro glacier has been
reported to be advancing and so are the 40 km long Rimo I and Rimo II
glaciers, which means that these glaciers are actually growing. Quite
interestingly some scientists have attributed this growth to the lack
of human intervention. The average winter snowfall in this region is
10.5 m, which is not insignificant.
A combination of reasons for Gangotri’s retreat
So far I have tried to convince that due to global warming the
moisture
content and intensity of the summer and winter monsoon should
increase,
and they will penetrate deeper into the Himalayas causing more
precipitation. Perhaps this is happening already as evidenced from
the
earlier mentioned descriptions of the strong cyclones, severe floods,
intense rainfall in Rajasthan and growth of glaciers in the
Karakoram.
If this were the case, why 67% of Himalayan glaciers, particularly
Gangotri are in recession then? Some other glaciers such as Ratakona,
Pindari and Milam in the vicinity of Gangotri, say within the area of
a
radius of a hundred km, are also in recession. They are briefly
discussed below.
In Saraswati valley, north of the township of Badrinath, which is
about
50 km from Gangotri, hosts Ratakona glacier very close to high
altitude
Mana Pass. Situated at 5,443 m above sea level, Mana Pass has been
the
gateway to the Indo-Tibetan trade route since time immemorial.
Ratakona
glacier near the pass is about to dry up, and it has disappeared
entirely in the nearby Dhauli Ganga valley. Pindari and Milam
glaciers
that occur about a hundred km south east of Gangotri attract vast
number of tourists for trekking and a range of other adventure
sports,
and are fast retreating too.
The recession, even disappearance of these glaciers is due to a
combination of reasons, two main ones being population pressure, and
massive deforestation. The holy township of Badrinath at an altitude
of
3,415 m above sea level is located on the banks of the Alakananda
river
which joins the Bhagirathi to form the Ganges. Although Badrinath is
home to only about 900 people, in 2006 season the holy town received
about 600,000 pilgrims up from 90,000 in 1961. Now, in 2008 the total
number of pilgrims and tourists trampling Badrinath, Kedarnath and
Gangotri, is perhaps well over a million. A hundred years ago no more
than a few dozen souls lived here, and barely a few hundred came on
pilgrimage, and most importantly they all travelled on foot.
Badrinath
was then the site of the holy temple and a few nondescript little
dwellings where a few sadhus lived. Now Badrinath is a sprawling
township with many luxury hotels and guest houses offering spacious
accommodation to these battalions of tourists and pilgrims. The
construction boom at Badrinath is showing no signs of abating. Fifty
years ago, there was virtually no vehicular traffic, and now the
roads
to Badrinath and the nearby holy towns of Kedarnath and Gangotri are
choked full of flotillas of buses, trucks, jeeps and cars spewing
obnoxious hot gases all the way up from their origin in the townships
of Rishikesh and Haridwar at the Himalayan foothills some 300 km
away.
These vigorous human activities are causing significant amounts of
local warming.
Each human body is a source of heat, and a million trampling the
sites
of Badrinath, Kedarnath and Gangotri every year give off more heat
than
a giant blast furnace; the heat is enough to scare the glaciers into
a
retreat. Had this many stampeded on to Her Majesty Queen Victoria’s
Vice-Roys, the all powerful and all oppressive British Raj would have
beaten a hasty retreat, half a century before 1947, and what to talk
of
poor Gangotri! What chance does Gangotri have to stand her ground
against such a sustained onslaught by so many for so long, but to
retreat! I am amazed that she is still there! And let us not blame
this
heat on global warming for the simple reason that when a room gets
warm
because of an electrical heater switched on, the warming is local and
not due to global causes. I have not mentioned yet, the inimical
effects of the massive deforestation on the glaciers, which is
rampant
even total, in these areas and the rest of the Himalayas.
Badrinath, Gangotri and all the nearby townships now stand on
forest-land stripped bare. These human habitations were much smaller
a
century ago, and were surrounded by thick forests, which are now
completely gone. The scale of deforestation here is absolute, full
one
hundred percent. My readers may be surprised to know the extent of
deforestation in the Himalayas as a whole. The dense Himalayan
forests
have been so denuded in so many areas that vast patches of deserts
have
replaced the forests. A study published in 2001 on the deforestation
of
the Himalayas in Himachal Pradesh using remote sensing techniques
shows
the forest cover to be only 17.15 % . This result is perhaps true for
the entire Himalayas, and what a shame that is for us all in India!
In
an attempt to further humiliate us all, I cite Japan, an advanced
industrialised country where I live these days, and whose population
density at 340 persons per square km is higher than that of India at
330, has a forest cover of over 70%, I repeat over seventy percent!
Forests invite rains, and as we destroy the forests, the Himalayas
refuse to attract the monsoonal precipitations. Moreover, the local
warming that we generate because of the million plus tourists and
pilgrims in the townships of Badrinath and Gangotri, chases the
monsoon
clouds away. And the consequence is that at a time when monsoon is
getting more intense due to global warming, certain pockets of the
Himalayas like Gangotri glacier will receive lesser precipitation
forcing her to retreat. This is comparable to the paradox of Plockton
that I elaborated earlier in the text.
Retreating Gangotri and the need for creation of a series of
glacial lakes
Glaciers scour the ground they travel, and transport the un-assorted
mixture of clay, sand, gravel and boulders, known as glacial till
depositing them along their flanks often forming substantial
embankments known as lateral moraines. These glacial rocks and
debris,
when deposited at the snout where the glacier ends, form the terminal
moraine. These moraines, terminal and lateral often impound glacial
melt water from the retreating glaciers to create glacial lakes in
the
void left behind. There exist many natural glacial lakes in the
Himalayas as well as in other temperate and polar regions of the
world.
In fact in the last few decades many glacial lakes have been forming
at
the termini of the glaciers in Bhutan-Himalayas.
Terminal moraines that act as natural dams for glacial lakes are
inherently weak, and often, because of natural reasons again, break,
causing glacial lake outbursts. The ensuing floods are known as
glacial
lake outburst floods, and are a common hazard in the Himalayas. Such
floods are quite devastating, and have wreaked havoc in the past in
China, Nepal and India. Consolidation of glacial till of the
moraines,
particularly the terminal moraine not only reduces the risk of
glacial
lake outbursts but also helps in the formation of relatively stable
glacial lakes. Formation of a series of such lakes at suitable
locations in Himalayan valleys where glaciers are in retreat,
particularly at Gangotri, would create sources for ground water as
well
as surface water flow. In this context I remember Professor K S
Valdiya, an eminent Himalayan geologist who I had the good fortune of
interacting with during my stay with the Department of Science and
Technology of the Government of India, had suggested the construction
of a number of small scale gravity dams across upper reaches of the
Bhagirathi to impound the melt-water from Gangotri glacier in a
series
of reservoirs. His decade old suggestion should be carried out to
conserve the precious water. The reservoirs may quite unwittingly
attract more precipitation to the region.
The concept of formation of a series of glacial lakes in the
Himalayas
at high altitudes need not scare the extremely powerful anti-dam
lobby
of India, as there already exist many such vast natural bodies of
water
at considerable elevations say over 4,000 m above sea level. I would
name a few here, such as Dashaur lake near Rohtang pass at 4,200 m,
Manimahesh lake in Chamba of Himachal Pradesh at 4,200 m, Tsomgo lake
in Sikkim at 3,700 m, and the largest lake Pangong Tso at 4,600 m.
Pangong Tso located at India China border is up to 8 km wide and
stretches over 134 km. Moreover, the other large Himalayan lakes such
as Mansarovar spread over 320 square km at an altitude of 4,600 m
above
sea level, and the nearby 70 square km Rakshastal at 4,750 m. I would
also like to add that these lakes are often the sources of many
Himalayan rivers like Mansarovar is for the Indus. Should a series of
lakes be created on the upper reaches of the Bhagirathi all the way
to
Gangotri, they will impound enough water and replenish the ground
water
table enough to prevent the Ganges from becoming seasonal. It will
not
be out of place to record here that glacier melt water constitutes
only
a minor proportion (5 to 10%) of the overall runoff of the Ganges;
however, the melt water is crucial as it maintains the Gangetic flow
during the pre-monsoon summer months. Water impounded in the glacial
lakes could well replace the glacier melt water, while making the
Ganges perennial.
The legend of King Bhagirath persuading Goddess Ganges to descend
from
her heavenly Himalayan abode on to the plains to save the multitudes
might not be an allegory; it may well contain some elements of truth.
The legend could well be the historical account of a massive civil
engineering project King Bhagirath undertook to break the terminal
moraine of a glacial lake to channel the water to irrigate the plains
parched by a prolonged drought. Many such glacial lakes formed by
retreating glaciers after the end of the last ice age, 18,000 years
ago, and are forming naturally even today. King Bhagirath utilised
the
water by breaching a terminal moraine then, and let us harness the
water for rejuvenating the Ganges by consolidating the moraines now.
Need for massive afforestation of the Himalayas now
Occurrence of Himalayan glaciers at various altitudes depends on a
range of conditions that include total annual precipitation,
latitude,
topography and aspect. Glaciers in the eastern Himalayas occur at
higher altitudes compared with glaciers in the central or western
Himalayas. For example, the lowest average elevation of glaciers in
Arunachal Pradesh in the east is at 4,350 m above sea level, in
Garhwal
and Kumaun in the centre is at 4,000 m, while in Kashmir in the west
it
is at 3,700 m. Now due to an increase in the average Himalayan air
temperature anywhere between 0.6 to 1.0 oC since the mid-1970s
because
of global warming, the snowline, which is the lower limit of
perpetual
snow, will move to a higher altitude. As the snowline migrates
higher,
the Himalayan tree-line, the altitude above sea level at which trees
cease to grow, will rise higher too, thus making larger areas
available
for the growth of forests.
With the onset of global warming there is every possibility of an
increase in rainfall in the Himalayas, and as nature provides a
larger
area for forests to grow by raising the tree-line, a massive and
sincere campaign for afforestation must be undertaken now, before
Himalayan forests lose their ability to regenerate. As a part of this
afforestation campaign, each and every pilgrim as well as tourist,
must
plant a sapling of a native tree and must pay a certain amount of
money
towards the management of the forests. A great deal of care should be
taken in afforesting the lateral moraines or the sidewalls, which
traditionally supported abundant vegetation as they contained higher
quantities of soil moisture. A successful regeneration of Himalayan
forests will reduce local-warming, attract higher rainfall, lead to a
higher retention of water in the aquifers, and will contribute to a
steadier supply of the runoff in the Ganges.
Conclusion
Gangotri glacier may well disappear in the future due to a lethal
combination of massive deforestation, population pressure, influx of
pilgrims and tourists, and local and global warming. But if we start
caring for the Ganges now on, which would involve formation of a
series
of glacial lakes, undertaking a massive programme of afforestation
right from the foot-hills up to the elevated tree-line in the
Himalayas, taking drastic measures to reduce the local warming, and
reducing the pilgrim and tourist pressure, she will rejuvenate
herself
to a great extent, and will continue to remain perennial. But are we
resolved to look after her?
I conclude this article by citing Ganga (Goddess Ganges) from the
Mahabharata when she says, ‘I will stay as long you continue to
address
me respectfully by my proper name, and will leave should you use any
abusive word to call me by’. This statement perhaps always had a
deeper
meaning, and meant that the Ganges will flow perennially if treated
properly with respect and affection; but would cease to flow if
mistreated. With the massive deforestation of her catchment,
metaphorically we have disrobed her to her utter degradation.
Deforestation has triggered a reduction in monsoonal precipitation,
and
lowered the groundwater reserves, and the two have combined to reduce
the steady round the year runoff in the Ganges and her tributaries.
Deforestation, moreover, has accelerated the loss of top soil and has
increased the frequency and magnitude of Himalayan landslides, which
have collectively supplied a vast quantum of sediments that have
choked
the channels of flow. And the final humiliation we have caused her is
the release of vast quantities of untreated sewage, virtually along
the
entire length of her course. With our mistreatment we have made
Mother
Ganges ill. She is now showing her annoyance through the recession of
Gangotri glacier. It is time we wake up, and start caring for her now
on, and if we do, she will regain her health and will remain
perennial,
she will not leave us.
Apathy, inaction, resignation and despair are ruinous; let mass action
commence to keep the Ganges perennial.
Can Global Warming Make The Ganges Run Dry?
Dr Nachiketa Das
Director, NRI-Enviro-Geo-Tech- Australia, Sydney; School of Kaya Yoga,
www.kayayoga.net
(First published on September 6, 2008 on www.hotnhitnews.com.)
[Professor Dr Nachiketa Das holds a Master of Science degree in
Geology
(Environmental Sciences) from the School of Environmental Sciences of
Jawaharlal Nehru University, New Delhi. A recipient of Commonwealth
Academic Staff Scholarship tenable in the UK, Dr Das, did a Ph.D. in
geochemistry from Glasgow University, Scotland. He was an officer of
Harvard University where he conducted postdoctoral research on
chemical
evolution of atmosphere and oceans. Dr Das served the Ministry of
Science and Technology of the Government of India and managed several
national and international programmes in earth, atmospheric and
environmental sciences. Dr Das has worked as an environmental chemist
with La Trobe University, Melbourne, and as a geochemist with
Commonwealth Scientific Industrial Research Organisation (CSIRO) of
Australia. Dr Das was a director of a Business college in Sydney, was
a
consultant to the Department of Foreign Affairs and Trade, and
Department of Industry Science and Tourism of the Commonwealth
Government of Australia.
At present he is a director of NRI-Enviro-Geo-Tech Australia, a
Special
Associate Professor of the Department of Earth and Planetary Systems
Science of Hiroshima University, Japan.
Professor Das is a dual citizen of India and Australia, and currently
resides in Japan with his wife Mrs Shizuka Imamoto. Professor Das is
a
practitioner of Kaya Yoga, based on the principle of moderation,
details of which are available on the website, www.kayayoga.net.
Professor Das is also an award winning creative writer, and has
published two books in Oriya, Kichhi Katha (a collection of
short-stories), and Berlin-Berlin (a travel story). Two of his
manuscripts in English, Kaya Yoga: Road to happiness, health and
longevity, and A Pilgrim’s Journey, are awaiting publication.
Professor
Das has many publications in earth-sciences, popular science,
international relations, and current
affairs.
http://drnachiketadas.sulekha.com/