At Rohtang Pass, the world changes. The green hills of Himachal Pradesh’s Kullu district have vanished somewhere in the steep climb from –Manali. At this time of year, the mountains are clad in snow and the winds icy, making the sun’s warmth particularly welcome. At 13,000 feet above sea level, Rohtang is the doorway to a colder, harsher realm. Winter temperatures often fall below -10°C.

Beyond the pass, the river Chandra guides visitors like a shepherd to the Lahaul valley. The metaphor is appropriate as large herds of sheep and goats are a frequent traffic snag. They are bound for winter quarters.

We are bound for Batal, a hub and base camp for treks into the freezing wilderness. The road is bumpy, particularly bad from Chatru via Chhota Dhara to Batal. At times the river bed becomes the road. Bouncing as if it’s on a spring mattress, the four-wheel vehicle enters Batal, where the cold wind greets us like a slap in the face.

Surrounded by snow-clad mountains, Batal is a tiny settlement on the banks of the Chandra. The only cemented building here is the Public Works Department guesthouse. Chacha and Chachi run a small teashop next to the bridge on the river. They have been here for more than 14 years. Their temporary shelter has saved many lives in times of crises; as a result the government has installed a satellite phone in their shop.

“Jule, jule (Welcome, welcome),” Chachi greets us with a warm smile that seems to somewhat lessen the frosts. As we enter their yellow-roofed shack, we are taken aback to find it overflowing with chocolates and biscuits. “We have spent the last 14 summers here, comforting travellers who cross this bridge to go to Spiti. We have seen the violent side of nature many times. But it also provides for the needs of all life on earth.”

Chacha smiles while narrating memorable but uncanny incidents from his life in Batal. His stories accompany us as we wade into the strong winds, at the start of a one-and-a-half hour trek to the Batal glacier.

I am with a team of scientists monitoring the glacier. We start out in bright sunshine but fierce winds. The gusts are particularly strong and do not allow people to remain at the glacier for too long.

“High wind speeds and the swirling effect at the snout make it difficult to move around the glacier after noon,” our cautious tour guide Pritam tells me. “So I have to ensure that the team leaves the area before the winds become stronger.” Fair enough; his major concern is the people entrusted to his care, though the mothering can be irksome.

We are walking in a dry, barren landscape. There is no sign of life here, neither plant nor animal. The terrain is rugged and grey, with stones and pebbles scattered everywhere. The wind is an ever-present companion. At this altitude, in the thin air, the lungs ache from the effort of drawing in enough oxygen. We are often reduced to breathing through open mouths, but the sound of our laboured breath is camouflaged by the howling wind. We get there eventually, stumbling along the ridges and moraines made by the glacier.

The first glimpse of the Batal glacier is a bit of a disappointment. It’s a dark, dirty grey, covered with debris, and even the snow is discoloured.

People think glaciers are white, covered with snow, but the truth is that most of them are covered with debris.

“People think glaciers are white, covered with snow, but the truth is that most of them are covered with debris,” says Dr Sunil Dhar of PG College, Dharamshala. He is studying the paleo-geomorphology of glaciated regions. “The debris comprises mostly the rocks that fall on the glacier from its very walls,” he adds. “But take a closer look. See the ice beneath all that muck? That will tell you this is a glacier.”

It’s been a year since they were here last, and Dhar and his team are looking for geomorphological changes in the glacier. Batal is a part of the study they’ve been conducting on the glaciers of the Chandra river basin for the last 15 years. Of the 150 typical glaciers in the area, they have chosen some benchmark examples such as Sissu nala, Chhatru nala, Samudra Tapu, and Chhota Shigri to study.

They are here this day to check and confirm rather than get into a long-term study. The data they have from remote sensing and earlier field studies have already been mapped. Now they want to see the glacier with their own eyes, to check the satellite data against real measurements on the ground.

We spend about two hours at the glacier. We’re warmly clad but the wind searches out every crevice in our clothing.

It’s hard to stand even a few minutes without shivering, but Dhar and his disciples seem oblivious to the wind and the freezing cold. The team measures the longitude and the latitude of the features visible on the satellite images.

They also mark the position of the snout on the satellite images. Changes in position will help gauge deglaciation, if any. The main aim is to match the features visible in the satellite imagery to that on the ground. The details will be used in the lab for geo-referencing.

The group has been here about a week, taking readings of the thickness of the glacier with the help of a ground penetrating radar or GPR. It provides fine details of the thickness and the materials present in the glacier. On an average working day at Batal, they spend three to four hours regardless of the weather. They have to return before noon because of the rising winds, so they have to rise early for the daily trek.

After they go back, the team will continue to monitor the glacier by satellite. They will return only next September to check the ground reality again.

Dhar explains, “We use satellite imagery to identify the changes in the field. We orient ourselves using the satellite images and pinpoint certain features so that we can geo-reference them in the lab. In a year one cannot observe much, so I cannot say what has happened in the last one year. We look for any recessional features (a sign that the glacier is losing ice faster than usual) or moraine deposits.”

Another scientist, who has visited Batal glacier many times, calls it “the most beautiful glacier with still the least changes even though it is near the road”. Milap Chand Sharma, Professor at the Centre for the Study of Regional Development, has been working on the Ganga basin for the past two decades and he is puzzled.

“I do not know how nature works. Batal is a glacier close to the road but has seen slight changes. It has reduced about three metres, which can be compensated any year if there is a good snowfall,” he says.

***

In India, glaciology became a hot field of research after the 2007 report on climate change by the Intergovernmental Panel on Climate Change (IPCC) predicted Himalayan glaciers would disappear by 2035.

The IPCC Fourth Assessment Report: Climate Change 2007 said: “Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the earth keeps warming at the current rate. Its total area will likely shrink from the present 500,000 square kilometres to 100,000 square kilometres by the year 2035 (WWF, 2005).”

Rajinder Kumar Ganjoo, director of the Institute of Himalayan Glaciology, has been working on glaciers since 1994. In the last two decades, the institute has studied five to six glaciers starting from Himachal Pradesh. Now the focus has shifted to Ladakh. The objective of the study is to find out how glaciers behave in terms of their increase or decrease in both volume and length.

He acknowledges the debt to the IPCC’s erroneous information, which in its report mentioned 2035 as year of the great doom when it meant 2135. “There were very few people working on glaciers till the IPCC report came out but now many more scientists are working on it. We realise that the change in climate has an impact on the glacier.”

In Ladakh, the glaciers are not showing any retreat in length or volume as compared to Himachal Pradesh or Uttarakhand. We are monitoring four glaciers in Ladakh and they have not shown any typical sign of decrease in length and volume.

Glaciologists across the board agree that there is a visible impact but they also say there’s no need to push the alarm button. Ganjoo explains, “In Ladakh, the glaciers are not showing any retreat in length or volume as compared to Himachal Pradesh or Uttarakhand. We are monitoring four glaciers in Ladakh and they have not shown any typical sign of decrease in length and volume”, as yet.

For instance, Ganjoo’s team monitoring the Kangriz glacier, has looked at records over the last 100 years and it has not moved an inch. There are glaciers which are at a standstill. But some are showing wide retreat: Siachen, for example. It is receding about 60 to 70 centimetres every year but looking at its length of over 70 kilometres, some scientists feel it is a negligible rate of retreat.

“It is not an alarming situation as has been predicted,” Ganjoo says. “As far as Ladakh is concerned, nothing will happen for another 200 years. The data coming out of Himachal Pradesh and Uttarakhand also show a trend of reversal, that is the rate of retreat has come down. In all the four glaciers we monitor in Ladakh there is no alarming
situation.”

Echoing the same line of thought, Dhar says, “We have seen an overall recession in the glaciers but it is not at the rate which has been predicted. It is not that the glaciers will vanish in a few decades. The situation is not so grim.”

While glacial studies have picked up markedly, there is a serious shortage of sorely-needed equipment. Despite working in state-of-the-art institutions, scientists do not, for instance, have automatic weather loggers which can take readings even in the dead of winter when living at such heights is impossible. These machines cost Rs. 3 lakh to Rs. 5 lakh, and now many institutions are beginning to procure them.

Sharma is happy to note that “we are getting an automated weather station very soon. We are strengthening infrastructure and instrumentation. Looking at the size of the country and priority there are small hiccups but they are being overcome.”

India suffers in a comparison with the state of glacial science in other countries, especially China. Our northern neighbour has had a dedicated institute working on glaciers for the last 50 years.

This is Ganjoo’s lament. “Even when we agree that it is essential to study glaciers, we don’t have an institute for it. I feel that the time has come, the government should realise that it is an important issue.”

One crucial obstacle to research is the difficulty in getting access to information. Satellite imagery is crucial to follow glacial fluctuations but it is difficult to obtain and the costs are extremely high.

V. K. Raina, former director of the Geological Survey of India and a member of the Expert Committee on Climate Change, complains, “One image costs me around Rs. 30,000 to Rs. 40,000 and it is not easy to acquire, especially for individuals who are not a part of any institution.”

Data collection has been a cause of concern for years. Weather stations in the higher regions enable scientists to collect data related to temperature, precipitation, solar radiation, and depth of the snow in a season. But with so few stations in place, reliable data from different locations is simply not available, giving rise to speculation.

This means, Sharma points out, “we are not confident about the predictions that are made. We are trying to get the data and how can the [insufficient] data prove what is happening? Till we have it, we are just guessing.”

The Indian Meteorological Department provides data mostly from the plains, as most of its infrastructure is in these areas. Hence, there is no authentic data about high altitude weather systems.

Raina says, “There are no weather stations to measure the claims of some scientists that winter precipitation has reduced. All is being said on the basis of interviews with locals or some odd observations in Delhi. We have been requesting the government to have weather stations on the Himalayas to measure the snowfall.”

According to meteorologists, at high altitudes their science is quite different from the low altitude or plains area studies. The weather systems that operate at low altitudes or in the plains differ from those at higher altitudes. There is no relation between the two.

“If Mumbai temperatures are going up, it is not necessary that temperatures at 4,000 metres and above will also be going up,” Ganjoo says. “We need 30 years of data to draw a good inference. Five-year-old data will give some information about the weather systems there. It is in a young state; the data is still to come.”

Though the few automatic weather stations installed at high altitudes provide pitifully inadequate data, given that the Himalayan system is gigantic, the meagre returns do provide a glimpse of what is going on.

The contradictions in glacial studies are pushing scientists to believe that there is more than meets the eye. They are beginning to see regional topography and climatic conditions as crucial factors in glacial retreat.

The contradictions in glacial studies are pushing scientists to believe that there is more than meets the eye. They are beginning to see regional topography and climatic conditions as crucial factors in glacial retreat.

Sharma and his department at the Jawaharlal Nehru University (JNU) have done a paper on a decade’s fluctuation in the Himalayan glaciers, some 1,800 of them. The paper uses photographic and satellite imagery from 2001 and 2011.

“We used the same data source and found that 87 per cent glaciers are stable. Twelve per cent are retreating. Roughly one per cent are showing advances in the Karakoram range. So it is interesting that the majority are stable as per decadal fluctuations,” Sharma muses.

Explaining the phenomenon observed in Karakoram, associate professor A. P. Dimri from the School of Environmental Sciences, JNU, says, “Since Karakoram is a cold desert the temperature is not increasing. The glacial dynamics remains the same so the glacial mass is not changing. In the central and north-eastern Himalayas, there is a change in climatic patterns and these are noted changes in the climate. Henceforth it will be cascading to the fluctuations of the glacial mass and glacial dynamics per se.”

A paper in The Geographical Journal of September 2013 says that in the Turgen Mountains of north-eastern Mongolia, the ice in the upper glaciated zones above 3,500 metres appears to have changed very little in the last 100 years.

The extent of coverage and thickness of the Turgen ice cap is almost identical between 1910 and 2010.

In Pakistan, there is no bad news as a recent paper on Nanga Parbat says glaciers are gaining mass. There is no problem in Tibet as it is 4,500 metres above sea level where the temperature is always low.”

Scientists believe that regional patterns are crucial to the glacial mass. Dimri points out the difference. “The western Himalayan glaciers are much drier than the eastern Himalayan glaciers. North-east glaciers have a large-scale monsoonal flow in the summer and most of the precipitation is received in the summer from the monsoon, whereas the western Himalayan glaciers receive winter precipitation, which is drier. So the regional climate fluctuations for individual glaciers may not be the same as the internal dynamics of glacial mass.”

Associate Professor Jayant K. Tripathi from the School of Environmental Sciences, JNU, explains the phenomenon of Argentina’s Patagonian glacier receding at a faster pace than normal. “Melting has to do with the spin of the earth. The oceanic currents and other factors work on these glaciers. If ocean temperature is high, the evaporation and subsequent precipitation will be higher and will lead to melting.”

The health of a glacier has many parameters that need to be determined before a judgment can be made. Ganjoo explains: “We try to look for change in parameters like sunshine, temperature variation, and snow precipitation. We use the data provided by weather stations to infer how different parameters affect the glacier.”

Scientists also try to build a history for the glaciers by looking at the geology. It helps them to go back in time as far as they can; in some areas about 20,000 years’ worth is available. It helps them understand the size and volume of that glacier. Based on the past and present, they calculate a rate of retreat.

“If we have good data on past and the present we draw a future model,” Ganjoo says. “We see if there is any relation between the changing health of the glacier and these parameters.”

The inferences can be complex. For instance, more sunshine does not mean glaciers will melt or even that rising temperatures will melt a glacier. There are many other variables: whether it is a clean or dirty glacier; whether it has a layer of debris or is free of debris. If there is less sunshine, then too glaciers could melt as surrounding dust can absorb heat and retain it. If the glacier is clean and has no dust or debris, it reflects sunlight as the albedo is high: the proportion of the incident light or radiation reflected by a surface, typically that of a planet.

The amount of energy that is radiated back into space depends on the surface. The temperature difference between a clean ice surface and one with debris is almost 6°. Debris sometimes melts the glaciers but sometimes also shelters it.

Sharma explains, “The energy absorbed in the glacier surface ultimately percolates down to the glacier fluxes within the glacier mass or glacier layer and if this does not happen, then the metamorphism within the glacial body will be different than the surface energy received.” In other words, you need specific and reliable data for accurate predictions.

There is evidence that the earth was once a giant snowball. There have been five known ice ages in the earth’s history. Within the ice ages, there have been glacial periods and temperate periods called interglacial periods. If we take a time span of 20,000 years, the glaciers have retreated and advanced as well.

Raina points out, “It is a cycle called the glacial and interglacial cycle. The temperatures become colder and help in the growth of the glacier and there are some cycles when it is warmer and the glaciers starts showing a retreat. According to one scientific theory, every 30 years glaciers either advance or retreat. If we look at the glaciers here, they fit into this model.’

So how do scientists explain global warming and its impact on glaciers?

Sharma feels global warming is more political than scientific. “There are many papers that claim warming is stabilised but they are not being talked about. It has to do with geopolitical factors.”

Ganjoo says, “The Himalayas are punctuated by about 6,000 glaciers (9,000 glaciers as per the latest inventory). Only 20 to 30 glaciers throughout the Himalayas have been studied in detail and monitored on a regular basis. The meagre data generated with respect to the vastness of the Himalayas needs to be projected with caution. It is rather more than premature to talk about the effects of global warming on the Himalayan glaciers on the basis of data from the study and monitoring of barely 20 to 30 glaciers.”

If for a moment one assumes that global warming will melt all the glaciers, will we see a great change in the planetary albedo? The planetary albedo is 30 per cent and it depends on the regional vegetation, water and ice in different places.

Dimri says, “It is too hypothetical to say that if all the glaciers melt, albedo will change. Melting of glaciers will not affect the planet as they are a small part of the planet. But if ice melts off then there will be a great change on the planet and there will be oceanic change.”

The threat to glaciers is deemed to be dire, but studies in the last few years point to a less bleak scenario. Even IPCC in its present report agrees that glaciers continue to shrink and lose mass globally, but that there are notable regional exceptions to these trends.