In a voice that carries the weight of the Himalayas, Naveen Juyal is hoping that it is a transient response to climate change. He is referring to snow disappearing from Om Parvat.

Om Parvat is in the Vyash valley of Pithoragarh district in Uttarakhand, at an altitude of 5,900 metres, on the borders of India, China and Nepal. People revere and worship the mountain because snow falling on it settles in the symbol Om. Actually, it accumulates in a cavity in the shape of the symbol Om and lasts through the year. For the first time this year in living memory, the snow melted in August. Tourists and pilgrims started flocking to the mountain after a road was constructed in 2019 to Lipulekh near the China border.

Juyal, a retired geologist from the Physical Research Lab in Ahmadabad, knows the mountain. While in Ahmadabad he worked on understanding long-term climate variability, impact of sea level changes, and dune dynamics. His research broadened into understanding river systems and glaciers. After his retirement in 2018, he has been working on glaciers, glacial lakes, glacier recession, permafrost areas with an emphasis on extreme hydro meteorological events, their causes and impacts.

Juyal explains that Om Parvat’s cavity was carved by glacial processes. In that area, he studied how the glacial lake formed and what caused it to recede. All the evidence was preserved in the sediments.

More recently, the Kali river valley underwent many changes. The river is the boundary between India (Uttarakhand) and Nepal and comes from Lipu lake and is on the Kailash-Manasarovar route. For instance, Garbyang village, known as the sinking village, was a thriving community on the Indo-Tibetan route, prior to the China war in 1962. It fell into ruins after the war.

Juyal says that when people lived there, the village was maintained well. But once trade was disrupted, these people were given the status of a tribe; they had money and they migrated.

“A lot of villages in the Himalayas are like that,” he says.

The particular depression on Om Parvat gets filled with snow in winter. After winter, it disappears from the area surrounding the mountain. But the Om-shaped snow lingers as the elevation of Om Parvat is high enough, even if quantity varies. The snow melted this time.

“That is an indication that Himalayan glaciers are melting at an alarming rate,” Juyal says. As per the Kathmandu-based International Centre for Integrated Mountain Development(ICIMOD) report, the Hindu Kush Himalayan glaciers have lost 65 per cent of their glacial mass.

“The Hindu Kush Himalayan (HKH) region, covering more than 4.2 million sq km, encompasses the highest mountain ranges in the world and contains the largest volume of ice on Earth outside the polar regions, as well as large expanses of snow. Spanning some 3,500 km from Afghanistan in the west to Myanmar in the east, and covering parts or all of Pakistan, India, China, Nepal, Bhutan, and Bangladesh, the HKH is home to unique cultures, highly diverse landscapes, and all of the world’s peaks above 7,000 metres.”

The HKH cryosphere—glaciers, snow, permafrost—is undergoing unprecedented and largely irreversible changes over human timescales, primarily driven by climate change.

The impacts are becoming increasingly clear, with increased warming at higher elevations, accelerated melting of glaciers, increasing permafrost thaw, declining snow cover, and more erratic snowfall patterns. The “water towers” of the HKH, critical for downstream regions, are some of the most vulnerable to these changes in the world, the ICIMOD report says. The Karakoram range, which was believed to be holding well till recently, is also showing loss of glacial mass.

“Glacier mass changes between the 1970s and 2019 in most areas of the HKH have now been quantified with increased accuracy. The rate of glacier mass loss increased by 65 per cent, from an average of –0.17 metres water equivalent (m w.e.) per year for the period 2000–2009 to –0.28 m w.e. per year for 2010–2019,” as per the report.

Furthermore, “there has been a significant decrease in seasonal snow cover during the summer and winter months, as well as a decline from mid-spring through mid-fall, indicating a seasonal shift.” The report also notes decrease in permafrost.

The High Himalayas are especially vulnerable to warming and climate change, Juyal says. “It’s called elevation-dependent warming.”

If the temperature rises in the plains by, say, one degree, in the High Himalaya, above 4,000 metres or so, it may rise by 1.5 degrees. That’s because snow has a very high albedo, which means around 90 per cent of solar radiation which falls on the snow is reflected. However, with increased warming, snow melts, exposing rocks, which absorb radiation.

“Solar radiation is going to get absorbed by those barren surfaces. The local heating will subsequently hit the surroundings, and this will have a cascading effect on the snow cover,” Juyal says.

The continual tourist influx is adding to the problem. India’s road projects for Char Dham have injected further instability and losses on the region. Power projects have already destabilised the mountains and rivers. Landslides have increased by 70 per cent.

Juyal has termed Om Parvat losing snow as a transient response to climate change at this point of time. Why transient? The response could be to some localised temperature rise in the area. This would have affected the amount of snowfall in the area. Less precipitation and more wild fires too.

Juyal flags the danger of winter temperatures rising.

According to this study, there is a change in “the long-term (1991–2015) and short-term (1991–2000 and 2001–2015) trends in winter temperature and precipitation over the Northwestern Himalaya (NWH) along with its constituents, i.e. Lower Himalaya (LH), Greater Himalaya (GH) and Karakoram Himalaya (KH). An overall warming signature was observed over NWH since maximum, minimum and mean temperatures followed rising trends with a total increase of 0.9 degrees C,0.19 degrees C and 0.65 degrees C, respectively, in 25 years.”

“It’s not just the summer temperature. It’s the winter temperature which is rising, and that is the major culprit for reducing the snowfall.”