Melting glaciers, changing climate

Published: October 29, 2014

Meena Menon

The HinduSCALING NEW HEIGHTS: Glaciology is not for the faint-hearted. Picture shows Mohd Soheb, a glaciology researcher, checking the precipitation gauge at the JNU base camp .Photo: By Special Arrangement

Though studies point to an increase in the pace of glacier wastage in the western Himalayas, long-term monitoring is required to study glacier evolution and its relation to the climate

At dawn, Mohd Soheb begins an arduous trek to the high camp at Chhota Shigri glacier in the Pir Panjal range in Spiti valley, Himachal Pradesh. From the PWD guesthouse at Chota Dara, he walks down to the Chandra river where he travels across in a small iron crate using an ingenious system of pulleys to the base camp at about 3,850 metres set up by the Jawaharlal Nehru University’s (JNU) School of Environmental Sciences.

From the camp, the snout of the glacier located at about 4,050 metres, looks deceptively close but actually requires a two hour climb over moraine. Covered by a sheet of dirty ice, it is almost blocked by stones but has a clear stream flowing from it which meets the river downstream at Chota Dara. Soheb will go ahead to 4,800 metres, to the high camp from where he will be carrying out studies. Steam drills are carried all the way up to dig into the snow and ice to place bamboo stakes up to 10 metres deep for measuring melting at intervals after the snout of the glacier. About 100 km from Manali, the glacier is relatively accessible, but for students like Soheb doing his M.Phil in glacier studies, the hardest part is getting there. The five-hour drive from Manali over non-existent roads is bone crushing and then the climbing over moraine filled with giant boulders. What is more challenging is measuring the winter snow accumulation, also called winter balance, just when the snow starts melting in late May, Soheb says. Last year he, along with other researchers, walked 30 km to reach the glacier since the area was snowed under and the roads were not open.

Glaciology, therefore, is not for the faint-hearted. JNU solved the issue of trained human resources by launching a programme from 2013 under a Department of Science and Technology (DST)- Indo-Swiss capacity building programme for budding glaciologists, training nearly 30 persons for advanced research in Himalayan glaciology. Chhota Shigri is one of the earliest glaciers in the country to be studied since 1986 as part of the Himalayan Glaciology Research Programme by DST. This was discontinued in 1989.

Mass balance study

Dr. Pottakkal George Jose, scientist at JNU and now part of the DST’s renewed project on Chhota Shigri glacier, says the idea of starting mass balance studies, which is the most accurate way of measuring glacier melt, was mooted in 2002. He explains that it is a benchmark glacier and is among the very few in the country that are being studied on a long-term basis with data on mass balance. Mass balance is the difference between the amount of ice gained by a glacier in winter and the amount lost in summer. A glacier which is gaining mass has a positive mass balance: more ice is added in the winter than is lost in the summer. A negative mass balance indicates that the glacier is losing mass. Chhota Shigri glacier met most of the benchmark requirements for the study.

“Studies on select glaciers have been carried out by the Geological Survey of India and the snout of the Chhota Shigri glacier has been found retreating”

A Status Report on the Chhota Shigri glacier in 2011 says that, “Apart from helping us to unravel the past climate, understanding the dynamics of Himalayan glaciers has their applicability in the environmental appraisal and mitigation of hazards like avalanches, lake outbursts, etc. in high altitude regions of the Himalayas.” Glacier snout position is the simplest indicator of glacier advance or retreat over a period of time which generally happens due to climatic fluctuations. Studies on Machoi, Sonapani, Bara Shigri and Chhota Shigri have been carried out by the Geological Survey of India (GSI), the Report says and the snout of the Chhota Shigri glacier has been found retreating in recent times.

Dr. A.L. Ramanathan, professor, JNU School of Environmental Sciences, says the mass balance studies on Chhota Shigri glacier have become a Bible of sorts for glacier studies and it uses standard field methodology. Since 2002 the glacier has the longest running series of mass balance measurements in the Himalaya range, he adds. A 2013 paper on the Chhota Shigri glacier by C. Vincent, Professor Ramanathan, Dr. Jose and others (in The Cryosphere 7, 569-582), points to the sparse field data on glaciers, adding that the study of the Chhota Shigri fills a gap in the knowledge of Western Himalayan glacier mass balance. However, the representativeness of the Chhota Shigri glacier cannot be extended to the rest of the Western Himalaya. It also stressed the need to develop ground based mass balance studies on benchmark glaciers in the Himalaya.

An inventory brought out by the Geological Survey of India (GSI) in 2009 shows that there are 9, 575 glaciers in the India administered part of the Himalaya, belonging to various climate regimes and only a sample reflecting certain benchmark properties can be taken up for study. In 2000, DST assigned Survey of India to prepare an inventory of major glaciers in Indian Himalayas which identified 327 major valley glaciers - 60 in Jammu and Kashmir, 85 in Himachal Pradesh, 162 in the Uttar Pradesh hills and 20 from Sikkim.

Poor sampling

A paper by Patrick Wagnon, A.L. Ramanathan and others on the Chhota Shigri glacier published in the Journal of Glaciology, Volume 53, No.183, 2007 says the Himalaya is the largest mountain range of the Hindu Kush Himalaya region but its glaciers are very poorly sampled in the field. One of the most recent and comprehensive global inventories includes only eight glaciers in India and three in Nepal with mass balance measured for at least a year, except Dokriani glacier in the Garhwal Himalaya which has mass balance surveyed over six years (1992-2000). With few long term studies ground measurements are needed for calibration and validation since mass balance cannot be measured from space, the paper says. The four-year study and remote sensing data indicate an increase in the pace of glacier wastage in the western Himalaya, probably related to global warming but long- term monitoring of Chhota Shigri glacier is needed to study the evolution of glaciers and their relation to the climate.

In an overview of the glacier status in Himachal Pradesh, Dr S. S. Randhawa, senior scientific officer of the Himachal Pradesh State Centre on Climate Change, says that glaciers are direct indicators of global warming and satellite data analysis of glaciers in Himachal shows retreat in glacier snouts, variation in snow cover extent and formation of moraine dammed lakes. The Himalayan ecosystem has 51 million people who practice hill agriculture and whose vulnerability is expected to increase on account of climate change. He notes an overall reduction in glacier area from 2077 sq.km. to 1628 sq.km. from 1962-2001 in the Chenab, Parbati and Baspa Basins, and overall de-glaciation of 21 per cent of total area in these basins. Studies by GSI of prominent glaciers in Himachal Pradesh shows a retreat in four glaciers including Chhota Shigri.

The Intergovernmental Panel on Climate Change (IPCC) underscores the need for glacier studies and says, “The water contained in glaciers and ice caps (excluding the ice sheets of Antarctica and Greenland) is equivalent to about 0.5 m of global sea level. Glaciers and ice caps are rather sensitive to climate change; rapid changes in their mass are possible, and are capable of producing an important contribution to the rate of sea level rise. To evaluate this contribution, we need to know the rate of change of total glacier mass. Unfortunately, sufficient measurements exist to determine the mass balance for only a small minority of the world’s 105 glaciers.”

With the new government’s announcement of a Centre for Himalayan Studies and DST support for research on nine benchmark glaciers in Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh, there is some hope that at least the need for such data is being taken seriously.

meena.menon@thehindu.co.in

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