K A L E I D O S C O P E

prime concern: CLIMATE CHANGE
As glaciers melt, life on a drip
Declining snowfall and receding glaciers in the Himalayas are a major concern not only for the hill states but those downstream too,  as they could be hit alternately by floods and dry periods.
By Rakesh Lohumi
A fallout of climate change, the melting of glaciers and the receding seasonal snow cover is emerging as one of the most important immediate environmental challenges for scientists and policy-makers. The implications are serious, and at stake is the very survival of life on this planet.

The retreat in Himachal raises the alarm
Affected by all the ills of development, Himachal is a particularly bad state for glaciers. The increase in construction activity, pollution and population are major areas of concern. One immediate threat to habitations in the hills is the threat from glacier lake outburst floods (GLOFs) caused by moraine-dammed lakes.

prime concern: CLIMATE CHANGE
As glaciers melt, life on a drip
Declining snowfall and receding glaciers in the Himalayas are a major concern not only for the hill states but those downstream too, as they could be hit alternately by floods and dry periods.
By Rakesh Lohumi

A glacier in the Karakoram range. Photo courtesy SASE

A fallout of climate change, the melting of glaciers and the receding seasonal snow cover is emerging as one of the most important immediate environmental challenges for scientists and policy-makers. The implications are serious, and at stake is the very survival of life on this planet.

The impact is not only more severe in the ecologically fragile Himalayan region but also of great consequence, as the river systems emanating from the towering mountain ranges cater to the largest chunk of human population on the globe. With the third largest deposits of snow and ice after the two poles, the Himalayas are often referred to as the “third pole”. The perennial snow deposits at the lofty heights serve as virtual water banks, ensuring a regular flow in the numerous streams that constitute the Himalayan river system.

The scientific community has become more circumspect after the faux pas committed by the Intergovernmental Panel on Climate Change (IPCC) by releasing a report predicting disappearance of glaciers by 2035. It now underlines the need for more extensive research and studies to generate authentic data regarding melting of glaciers and investigating its causes. However, all recent studies provide concrete evidence that glaciers and snowfields are retreating at an accelerated pace and barring a few, almost all of them have been showing a negative mass balance with ablation (loss) exceeding accumulation of snow.

It will not only disturb the eco-system but also affect the availability of water and food, without which life cannot be sustained. Any consequent alteration in the dynamics of the Himalayan rivers will put a question mark over the future of the hydroelectric projects already in operation and proposed to be set up. Food security and energy security is irrevocably linked to the availability of water and effective strategies will have to be put in place to at least slow down the process of melting, if it cannot be reversed completely.

However, it is easier said than done, given the complexity of the problem and its scientific, socio-economic and political dimensions.

Aerosols a culprit

Scientific investigations have shown that global warming caused by greenhouse gases (GHG) is not the only reason for melting of glaciers. Aerosols — suspended particles ranging from 0.01micron to 100 micron in size (1 micron = 1/1,000 millimetre) — are also contributing to the process in a significant manner through the process of “radiative forcing”. Unlike the greenhouse gases that warm up both the earth’s surface and atmosphere, aerosols heat up the atmosphere but cool down the surface. The black carbon in the Atmospheric Brown Cloud (ABC) formed by aerosols of varying sizes interact with the terrestrial and solar radiation, leading to back scattering, reflection and absorption, which has a dimming effect on the radiation reaching the ground and as a result it has a cooling effect. The Indo-Gangetic Plain is among the five regional ABC hot spots, the others being East Asia, Indonesia, Southern Africa and the Amazon basin in South America.

The black carbon in aerosols absorbs both incoming and outgoing radiation and causes more energy to accumulate in the upper atmosphere, which gets heated up. Thus, the net impact of ABC is warming up of atmosphere, explains V.K. Jain, Vice-Chancellor of Doon University, Dehradun, and an authority on air pollution. The impact of the ABC is maximum in the altitudinal limits of 3-5 km, and as such it has the most significant fallout for glaciers and snowfields. The scattering and absorption properties of individual particles depend on the particle shape, size, refractive index and wavelength of incident radiation. In effect, ABCs modify the radiation budget of Earth, leading to changes in the atmospheric system, which in turn has a bearing on temperature and precipitation. The greenhouse gases on the other hand trap the infrared radiation, which results in warming up of the ground surface and the atmosphere.

The black-soot aerosols falling on the glaciers darken their surface, reducing snow albedo (reflection of sunlight) and hasten melting. The only way out, asserts Jain, is to reduce the sources of black carbon (BC), which is contributed mainly by domestic fuel, transport and burning of agriculture residue. Globally, 20 per cent annual emissions of BC are contributed by bio-fuels, 40 per cent by fossil fuels and 40 per cent by biomass burning. A switchover from wood and cow dung to cleaner and more efficient fuels is an imperative.

Glacier inventory

As per the updated “Glacier Inventory of Indian Himalaya”, prepared by the Geological Survey of India (GSI), there are 9,575 glaciers, out of which 7,997 glaciers are distributed in the Indus catchment, and the remaining 1,578 are contained in the Ganga (968) and Brahmaputra (610) watersheds.

The studies carried out by the GSI have revealed that the majority of glaciers of the Himalayan region are passing through a phase of recession, as has been the case with the glaciers located in other parts of the world. The rate of recession is different in various climatic zones due to factors like morphology, macroclimate, orography (relief of mountains) and size of the glacier. The ones located north of the Pir Panjal range in Lahaul region show less retreat compared to those in the south in the watersheds of the Ravi, Beas and Sutlej. The higher retreat of glaciers of the Sutlej basin is attributed to the fact that they fall under the moisture shadow region of the Pir Panjal range.

Studies carried out by the State for Climate Change (SCCC), which monitored the behaviour of 250 glaciers to estimate the retreat, revealed that 5 per cent of the area was lost between 1962 and 1993 (including gain in some glaciers), 2 per cent between 1993 and 2001 and an alarming 12 per cent loss happened between 2001 and 2007. About 13 per cent deglaciation has occurred between 2001 and 2007 and a marginal loss of area, 0.44 per cent, between 1993-2001.

The total glacier area of 188 glaciers based on aerial size has reduced to 230.84 sq km in 2001 from 311.13 sq km in 1962, indicating an overall reduction of 25.8 per cent glacier area from 1962 to 2001.

While comparing the glaciers based on their aerial size, it has been found that maximum retreat of about 65 per cent has taken place in case of glaciers where area is more than 10 sq km between 1962 and 2001, followed by about 38 per cent area loss in 5-10 sq km glacier size range, 30 per cent in case of 3-5 sq km size range and 13 per cent in 1-3 sq km range. The number and the total area of small sized glaciers, less than 1 sq km, has increased to the fragmentation of large and medium sized glaciers during this period.

What is a glacier

A glacier is a large mass of ice gathered in places where the accumulation of snow exceeds its ablation (loss from melting and sublimation) over many years, often centuries. Glaciers gradually deform and flow due to stresses caused by their weight, creating crevasses, seracs, and other distinguishing features.

The problem

Global warming caused by greenhouse gases, along with tiny carbon particles suspended in the atmosphere from pollution, is causing glaciers to melt. These act as a bank of water, released gradually through annual melt. Their fast melting is likely to cause flash floods or reduced discharge of water in rivers subsequently.

The solution

Halting global warming is too big a goal to achieve. But slowing down its progress can be hoped for through reduced human activity. For glaciers, increased pollution and reduced green cover in the surrounding hills is also harmful. Construction in the hills, thus, needs to be reduced.

The retreat in Himachal raises the alarm

Tourist and construction activity, coupled with automotive pollution, affects glaciers too. A glacier in Kinner Kailash hills.

Affected by all the ills of development, Himachal is a particularly bad state for glaciers. The increase in construction activity, pollution and population are major areas of concern.

One immediate threat to habitations in the hills is the threat from glacier lake outburst floods (GLOFs) caused by moraine-dammed lakes. (Moraine is debris collected by the movement of a glacier)

With glaciers melting at an increasing pace, there is an increase in the number and size of moraine-dammed lakes, which could cause floods. The bursting of such a lake increases the discharge in its stream, causing flash floods in the downstream areas with huge loss of life and property. A total of 38 lakes have been mapped in the Sutlej basin — 14 are in Himachal and the remaining in Tibet — and 55 in the Chenab basin by the SCCC.

The GSI has identified one such lake located at an altitude of over 14,000 ft uphill of Shishu village in Lahaul as a potential threat. It has observed that the snout of the Gepang Gath glacier at an altitude is calving into a large proglacial lake, which is increasing in size due to the continued retreat of the glacier. Its size has more than doubled to over 0.66 sq km and it could give way in the event of a landslide or earthquake, causing flash floods in the downstream areas. It has advised the government to go for controlled release of water from the glacial lake to avoid a Parechu lake-like situation in view of its fast increasing size.

Receding seasonal snow cover

More than the melting of glaciers, the declining snowfall and receding seasonal snow cover during winter is a cause of concern and its impact is already visible in depleting water sources. Studies conducted by the Snow and Avalanche Study Establishment (SASE) reveal that the quantum of snow at Dhundi (close to Rohtang pass) at an altitude of 3,050 m has declined from about 1,400 mm to 800 mm and that of rain gone up from 200 mm to 800 mm over the 1989-2009 period. The number of days for which the snow cover lasted has come down from 138 to 110.

It is hardly surprising that the snow-covered Rohtang pass, which used to open around second week of June in the 1980s, is nowadays thrown open towards the end of April. More than climate change, the ever increasing human activity in the upper Kullu valley, particularly Manali, Solang Nullah, Marhi and Rohtang, is responsible for the declining snow. Unregulated tourism is indeed taking a heavy toll of the most sensitive high-altitude environment. Thousands of vehicles daily carrying tourists to Rohtang during peak season not only cause traffic jams but also pollute the rare atmosphere. The numerous hydro-electric projects are also causing environmental degradation in high-altitude areas.

Heavy urbanisation

Haphazard and unbridled urbanisation is also causing environmental degradation, leading to significant changes in micro-climates. The popular hill station of Shimla provides a classic example of how fast the destruction of green cover and expansion of concrete jungle can affect the weather. A study conducted by two meteorologists, SC Bhan and Manmohan Singh, has brought out that the quantum of snow has come down and most of the precipitation is in the form of rain and the snow season is shirking at the rate of 11 days per decade. The seasonal total precipitation and snow showed a decrease of 90 mm (1991-2001) and 57 mm (2001-11) per decade.

Instead of taking corrective measures, successive governments have made things worse by allowing builders to construct multi-storeyed apartments, making a mockery of Section 118 of the Land Reforms and Tenancy Act which debars non-agriculturists from purchasing land in the state. Consequently, green hills are being transformed into a veritable concrete jungle at a faster rate than ever before. It is the same story across the state and huge real estate projects are coming up in rural areas without any requirement.

Private universities are coming up by the dozen, including three in one panchayat, and most of them have been procuring water in tankers. The problem of water shortage has been further aggravated as a result in most part of Solan and some parts Shimla district.

Remedial measures

Besides switching over to cleaner and more efficient fuels and clean technologies in all sectors in a big way, long-term policy intervention is needed to keep the human activity to bare minimum in the highly eco-sensitive middle and high hill ranges. The government must realise that ecologically fragile hills are not meant for real estate business as they do not have the carrying capacity to support a large population. Any policy to combat climate change must recognise the fact that eco-sensitivity increases with altitude.

The apartment act needs to be scrapped — as recommended by the Select Committee of the Vidhan Sabha — and effective steps are needed to regulate tourism and prevent haphazard urbanisation to mitigate the local factors accentuating the process of climate change. RL

In the Alps

The Great Aletsch Glacier in Switzerland is the largest glacier in the Alps. It is about 23 km long, with an area of 120 sq km. The Aletsch Glacier is composed of three smaller glaciers converging at Concordia, where its thickness is estimated to be near 1 km. It continues towards the Rhone valley, melting into the Massa river. The Aletsch Glacier receded by 100 m (330 ft) between 2005 and 2006, a phenomenon affecting glaciers all over the world.

Height of loss

Glaciers located around an altitude of 5,000 m have shown 24% loss, as compared to 14% in those above 5,400 m. In addition, in the month of December and January snow melting was observed at altitudes as high as 4,800 m, which will have a profound effect on the stream runoff pattern of many glaciers and snow-fed streams.