The health of the Himalayas: We ignore glacial melt at our own peril

Satellite images shared by the Indian Space Research Organisation (ISRO) a month ago warn of Himalayan glaciers melting much faster, resulting in glacial lakes doubling.

This report reminds us of a fatal morning in 2021.

On 6 February, around 10.30 a.m., a chunk broke off from the silver glacier crowning the Nanda Devi range and fell into the Rishi Ganga river. Naturally, the fall of such a massive chunk from such a height caused a sudden rise in water levels.

The small power plant located in Raini village, near the well-known Valley of Flowers, was washed away in no time at all. The repercussions were visible up to 5 kilometres away, in the Dhauli Ganga, where the NTPC hydel power project was heavily damaged. Several bridges were swept away and communication between villages snapped.

It is worth noting that the residents of Raini village had approached the high court in 2019, questioning the wisdom of setting up a hydel power plant in such a sensitive ecological zone. The matter stayed unheard and tragedy inevitably struck.

The incident underlined the urgent need for rigorous research and systematic evaluation of using glaciers as a source of fresh water.

Glaciers on the Himalayan snow peaks are three feet thick and two kilometres long on average, formed where snowfall exceeds snowmelt. The Himalayan region hosts an astonishing 18,065 glaciers, none of them less than three kilometres long. Dragged down by their own weight, they move extremely slowly—hence the term ‘glacial pace’—barely 4–5 inches in 24 hours.

Another unique feature about the Himalayan glacial region is that it receives intense sunshine at least 300 days a year, for at least eight hours a day.

Snowmelt is thus an expected outcome.

While glacial melt is a natural process, increasing commercial activities and concretisation have also contributed. The unchecked emission of carbon dioxide and other greenhouse gases has adversely affected the temperature of glaciers.

With the advent and rapid spread of industrialisation, the natural rate of glacial melt has accelerated over the past 200 years. Even as existing lakes expand, new lakes are formed.

While these glacial lakes are the source of life-sustaining rivers, their overflow, or Glacial Lake Outburst Floods (GLOFs), can be devastating.

The ISRO report was extremely disturbing not just because the Ganga–Yamuna river system (recognised as India’s lifeline) flows through this region, but also because of the role its glaciers play in maintaining temperatures and ensuring good monsoons.

The ISRO satellite images show a 178 per cent increase in the area of the Ghepan Ghat glacial lake (4,068 metres high) from 36.49 hectares in 1989 to 101.30 hectares in 2022. This means an average gain of 1.96 hectares annually.

The report notes that 676 of the 2,431 Himalayan glacial lakes have expanded by 10 hectares or more between 1984 and 2016–17. The report elaborates that 601 of the 676 lakes have doubled in area; 65 have increased 1.5 times; and 10 have increased by 1.5–2 times their original size.

It is a matter of concern that 130 of the 676 glacial lakes that have expanded substantially are located within India.

One might reflect on the fact that 296 lakes formed by glacial melt are located above 5,000 metres; 14 between 4,000 and 5,000 metres.

One might recall the massive overflow of the South Lhonak glacial lake—located at an elevation of over 5,181 metres in northwestern Sikkim—last October. The consequent floods resulted in 40 deaths and 76 missing persons.

Himachal suffered a similar fate a few years ago due to the overflow of the Parechu lake.

The third largest accumulator of ice after Antarctica and the Arctic Circle, the Himalayas are referred to as the 'Third Pole'. This vast mountainous region spread over 2,000 km is estimated to contain 600 billion tonnes of ice, which caters to the water requirements of 75 crore South Asians.

Between 1975 and 2000, an average of 4 billion tonnes of ice melted annually. This doubled to 8 billion tonnes annually between 2000 and 2016.

The Himalayas are the prime source of water for the Indian subcontinent.

If we go by the 2018 water security report issued by the science and technology department of the Government of India, it notes a 60 per cent drop in the volume of water in rivers originating in the Himalayas. The concern over climate change and its adverse impact is no longer limited to environmental specialists.

Other aspects are being discussed too.

The full meltdown of Himalayan glaciers will lead to a massive rise in the volume of river water, thereby inundating many cities and villages.

On the other hand, increasing temperatures caused by the destruction of the glacial umbrella will result in terrifying cycles of drought, flood and heat.

Human life will definitely be threatened.

The Himalayan ranges of Uttarakhand contain 1,439 small and large glaciers, covering 20 per cent of the state’s area; the sole source of drinking water as well as the needs of agriculture, industry, hydel power and tourism. Any changes to the glaciers can only endanger the entire country’s environmental, social, economic and strategic well-being.

This self-evident fact led then-chief minister of Uttarakhand, Ramesh Pokhriyal Nishank, to propose in 2010 the establishment of the Snow and Glaciers Authority (SGA). Nishank invited ISRO to oversee this process with the cooperation of the Snow and Avalanche Studies Establishment (SASE), Chandigarh, and the Wadia Institute of Himalayan Geology, Dehradun.

Incidentally, he did not continue as chief minister much longer, and the project went into cold storage.

A decade ago, the International Panel for Climate Change (IPCC) predicted that the Himalayas will be bereft of glaciers by 2035. They cited the example of the Kolahoi glacier in Kashmir receding by 20 metres annually, even as a smaller glacier disappeared entirely.

Jairam Ramesh, then union environment minister, constituted a panel of scientists under the leadership of V.K. Raina.

This group studied the movement of 25 major glaciers over the past 150 years and found the incidence of glaciers moving or receding is fairly old—and has not escalated significantly in recent times.

In fact, 230 glaciers in the Hindukush and Karakoram ranges in the western Himalayas are growing. Similarly, glaciers on K2 in Pakistan and the Nanda Devi mountains are also advancing. Both the Gangri and Drang-Drung glaciers in the Ladakh region have not moved an inch over the past 100 years. Even the Gangotri glacier is receding at a much slower rate since 2000.

The group concluded that fears about glaciers disappearing are baseless. The IPCC neither contradicted these findings nor issued clarifications.

Professor R.K. Ganju of the University of Jammu & Kashmir also asserted that glaciers did not melt due to rising temperatures. If that were the case, he said, glaciers in the northwestern Himalayas would melt faster than those in the northeastern Himalayas.

As it happens, the exact opposite is true.

Glaciers are akin to children: even minor needling results in their withdrawal. Human interventions do cause glaciers to shift and shrink.

Consider that since 1953, over 3,000 mountaineers have hoisted their flags on Mt Everest. Several thousand mountaineers have climbed umpteen other less daunting Himalayan peaks, leaving behind piles of garbage. Disturbances that may be attributed to ‘local’ rather than ‘global’ warming also occur.

When there is a significant difference in the temperature between the top and bottom layers of a glacier, there are chances of big chunks shifting or slipping down. When two massive glacial chunks on the move collide, they wreak havoc—as happened in Raini village.

A study by the Wadia Institute of Himalayan Geology states that the Gangotri glacier, source of the Ganga, has of late been receding by 22 metres annually instead of the average 10 metres.

A report by the Central Pollution Control Board, titled ‘Biological Health of River Ganga’, states that the rate of glacial melt has increased with a 1-degree average increase in temperatures.

Either way, there is no doubt that glaciers are as vital to us as air and water. And that our dwindling river systems are a direct result of construction and explosions modifying the natural form of our precious glacial terrain.

It behoves us, then, to take stock and exercise caution.