Water and climate security at risk due to low snow levels in Hindu Kush region

A recent report noted a sharp decline in snow levels across the Hindu Kush Himalaya (HKH), raising serious concerns about water and climate security for over two billion people in the region. 

According to a recent report by the International Centre for Integrated Mountain Development (ICIMOD), the snow level in the HKH plummeted to a record 23.6 per cent low in the winter of 2024-2025.

Let’s understand what the report says and how organisations like ICIMOD play a significant role in supporting evidence-based policymaking in South Asia.

Melting cryosphere of HKH draws global concern 

The HKH is rightly termed as the ‘Third Pole’ of the world due to its vast ice reserves. Significantly, the region has the largest deposit of snow and ice beyond the two Polar Regions (the Arctic around the North Pole and the Antarctic around the South Pole). 

When it melts in summer, the snow from the mountains contributes about a fourth of the run-off of the 12 major rivers in the region, including the Ganga, Indus, Brahmaputra, Mekong and Amu Darya. This makes the cryosphere zones of the HKH not only significant for the climatic stability of South Asia, but of the entire planet. 

Despite its vastness, the cryosphere in the HKH has been under-studied. However, growing concern over the degradation of its various components as well as the unprecedented melting of the glaciers therein have drawn global attention towards it. 

These threats have prompted an increased push towards knowledge generation, regional assessments and state-sponsored research to produce more data and inform policy decisions. 

Shrinking snow cover raises red flags

ICIMOD, headquartered in Kathmandu, is one of the oldest inter-governmental organisations representing the interests of the HKH region. Its eight member-nations – India, Pakistan, Nepal, Bhutan, Bangladesh, Afghanistan, China and Myanmar – engage in collective knowledge generation, communication and application for the sustainable management of this sensitive high-altitude landscape. 

Since its establishment in 1983, ICIMOD has made significant contributions in generating useful knowledge for the common benefit of all member nations. In the domain of Himalayan cryosphere, it has been publishing annual Snow Update reports since 2003 that monitor seasonal snow anomalies and provide year-by-year assessments of snow persistence.  

Snow persistence is an important indicator of cryosphere health. It is measured as the fraction of time snow remains on the ground after snowfall. Shorter duration of snow cover indicates rising temperatures in the atmosphere and higher rates of snowmelt. 

Key findings of 2025 Snow Update report

— Since 2020, four winters have witnessed below-normal snow persistence levels in the region.

— The mean snow persistence in the 2024-2025 winter season evidenced a historically low snow persistence at -23.6%. This has been the lowest recorded in the past 23 years. 

— The snow persistence has been negative for all twelve major river basins. 

— However, it was alarmingly lowest in River Mekong at -51.9% and Salween at -48.3% and the lowest in Amu Darya at (-18.8%) and Indus (-16%). 

Snow is an important component of the cryosphere. Snow meltwater contributes 23% of water (on average) to total river runoff in the Hindu Kush Himalayan region.

In some states of India, such as Himachal Pradesh, snow supplies more than half water used for irrigation. Therefore, the decline in snow persistence, triggering early melting across the region, albeit at different rates, raises serious concerns.

Shrinking snow cover: Impact on water security and biodiversity

A persistent below-normal snowfall accompanied by an early melting away of snow may have several negative implications on water, biodiversity and society in the region. Some of them are – water availability, river flow and disruptions, impact on agriculture and allied sectors, and energy shortage. 

Water availability 

Because of the early melting of snow during the snowfall months of November to March (winter season), water availability in the spring and summer months may be reduced, affecting the water security of over two billion people across river basins in the HKH region. 

Due to intense developmental activities taking place across the HKH –– construction of tunnels, widening of roads, hydro-power and urban-infrastructure projects –– water demand is at an all-time high. 

High water demand, compounded by high ground-water extraction, may cause the ground water reserves, springs, aquifers to face extinction. Both of these –– reduced water flow and high water requirement –– potentially increase the risk of droughts across the region. During summer, water availability downstream could become a huge problem. 

River flow and disruptions

Snow mass and glaciers play a crucial role in regulating a river’s hydrological regime. The depletion of glaciers is leading to a significant decline in streamflows, especially in summer. 

Some scientists note that summer streamflows in certain rivers increased until the mid-90s due to increased melting, but have since reduced after reaching a tipping point. This suggests that many of the Himalayan perennial rivers are at risk of becoming seasonal in the future. 

Moreover, changes in river flow – quantity of water, the intensity of the stream, route of the flow – will drastically impact the nearby biodiversity, human activities dependent on river water and other ecological components such as soil fertility, forest cover and availability of water downstream. 

Impact on agriculture and allied sectors

Snow is particularly important for agricultural productivity. Adequate snowfall benefits both rabi and kharif seasons by ensuring sufficient water availability and leading to an increased cropped area. This extends to fruit crops, vegetables, and other horticultural crops. 

As snow declines, risks of worsening droughts and crop failures may increase. This poses a severe threat to agriculture and allied activities in the Indo-Gangetic plains – one of the world’s important breadbaskets.

Energy shortage

Hydro-electricity projects across the HKH are expanding, making it one of the world’s most dam-dense regions due to its abundant water resources and ideal topography. This topography – charactersied by fast-flowing water descending from a higher altitude to a lower altitude – is ideal for hydropower generation. 

However, disruptions in the speed, quantity and direction of streamflow could affect existing and upcoming hydroelectric projects. In this context, declining snow cover and shrinking glaciers in the HKH could severely affect renewable energy generation and pose challenges to India’s energy security goals.

Adaptation strategies

As a result, countries like India need to take into account assessments such as the recent Snow Update report and plan adaptation strategies accordingly. Some of the suggested measures are water management and drought preparedness, basin-level targeted actions, and national-level preparedness.

Water management and drought preparedness 

These include several components such as management of water demand and use by various groups, allocation of water to priority sectors, regulation of water usage, reducing water wastage and promotion of reuse and repurposing of used water; installing warning systems for possible water shortages and instating drought response strategies. 

Basin-level targeted actions 

Since snow persistence levels differ across different basins with the lowest snow-persistence levels in the eastern part of the HKH, and comparatively better trend in the western, different strategies catering separately to each basin will be helpful. 

National-level preparedness

National-level accounting of various water-availability scenarios and strategies for the various scenarios will be crucial. These include regulation of economic sectors such as industries, infrastructure and urban development across the Himalayan region; a paradigmatic shift in food systems, choice of crops, etc.; installing energy resilient systems such as hybrid solar-hydro or micro-hydro-solar-battery plants, community-owned micro-hydro projects, etc. 

To sum up, snow remains one of the least understood components of the HKH region. It governs the stability of the region and has far-reaching global consequences. As a result, snow assessments such as the recent report by ICIMOD, play a crucial role in promoting scientific, pragmatic, evidence-backed decision-making.

Post Read Questions

Why is snow considered one of the least understood yet critical components of the HKH region’s climate system?

What could be the broader environmental and social consequences of a continued decline in snow persistence across all 12 major rivers in the region?

What role do organisations like International Centre for Integrated Mountain Development (ICIMOD) play in supporting evidence-based policymaking in South Asia?

In what ways might the agricultural and irrigation sectors in snow-fed states like Himachal Pradesh be affected by early snowmelt?

What national-level strategies should India adopt to ensure long-term water and energy security in the Himalayan context?

(Aishwarya Sanas is a doctoral researcher at Shiv Nadar Institution of Eminence, Delhi NCR.)

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