Climate Change: Concern Spikes Over Lack of Snowfall in Hindu Kush Himalaya Region

Patna/Kathmandu: Climate change is real in the Hindu Kush Himalaya (HKH) region and its impact worries scientists. After 2023 recorded the hottest global temperatures, scientists’ latest concern is that this winter has been very unusual, with little or no snowfall throughout the region.

The lack of snowfall is bound to cause adverse ecological impacts in the region, including water, agriculture and agroforestry.

According to scientists of the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), mountain peaks in the HKH region – usually capped in a white blanket of snow in the winter – remain noticeably bare this year, particularly in the western Himalayas.

They have pointed out that temperatures have been warmer than average this season – a likely reason for the below-normal snow cover. “Even if there is significant snowfall in February and March as temperatures start to rise, it will probably be too little, too late to make up for the existing deficit,” Sher Muhammad, cryosphere expert at ICIMOD, said.

An ICIMOD’s release titled “Record low snowfall sounds alarm for water security in the HKH” categorically made it clear that lack of sufficient snow accumulation means that when the snow melts later in the year, there will be less ‘runoff’ – excess water which flows across the surface of the land and into nearby water bodies. With fewer snowfall events, there will be less snow on the ground, with decreased snow depth. This means less melted snow will run into rivers and streams when the weather warms up. So, less snowfall over time could substantially reduce water for agriculture when it is needed most.

Scientists said snow typically begins accumulating in October or November and continues until March, particularly in the western HKH region. 

Snow cover usually acts as an insulating blanket, shielding dormant crops, allowing root growth, preventing frost penetration, and protecting soil from erosion. Reduced snowfall and erratic rains across the Himalayan region can potentially cause adverse ecological impacts, including on water and agroforestry.

Global heating, a major facet of the climate crisis, is influencing various weather phenomena on both regional and global scales. Although the precise physical mechanisms are not fully understood, it is believed to be contributing to prolonged and more intense La Niña – El Niño conditions. These disruptions in normal weather patterns, in turn, impact the ‘Western Disturbance,’ a meteorological phenomenon with a significant influence on the hydrological regime of the Hindu Kush Himalaya. Consequently, this dynamic interplay affects the water security of the region’s population, scientists highlighted.

“An exceptionally dry winter could mean heavy snowfall in spring, which could bring catastrophes like avalanches and flash floods. We are moving headfirst into the reality of 1.5 degrees global temperature; what we are experiencing here is just a snippet of what is to unfold. Urgent action is required to build the resilience of Himalayan communities in the face of snow drought and its cascading impacts,” said Arun Shrestha, Senior climate change specialist at ICIMOD.

Low snowfall also has a direct and severe impact on agriculture. This is particularly acute for the HKH region, which is heavily dependent on agriculture.

Mountain communities already face numerous challenges, including crop failure, livestock deaths, fodder shortages, loss of life and property due to disasters, and psychological distress. The extremely dry winter follows years of below-average snowpack accumulation and is expected to strain water resources further this spring and summer. 

With rivers fed by mountain runoff potentially running dangerously low, farmers may be unable to irrigate fields or sustain livestock. Food insecurity, economic losses, and migration could intensify without adequate adaptation measures.

Arshini Saikia, Atmosphere Scientist, ICIMOD, said that temperature anomalies in 2023 have weakened and delayed the Western Disturbance, affecting winter precipitation, crop production, and snowfall in the western Himalayan region. “The consequences of the temperature anomaly in 2023 were observed in many parts of the HKH region. What we are experiencing is the reality of what 1.5 degrees means for the HKH,” Saikia said.

The Western Disturbance serves as the main source of snowfall that nourishes the HKH glaciers, particularly glaciers in the western part of the region; for eastern Himalayan glaciers, summer precipitation is the main source. These glaciers play a crucial role in feeding major rivers such as the Ganges, Indus, and Brahmaputra, as well as numerous mountain springs and rivulets.

The 2023 annual climate summary report, as presented in the monthly Climate Bulletin of the European Centre for Medium-Range Weather Forecasts (ECMWF) in January 2024, summarises how El Niño – La Niña and Western Disturbance contributed to below-normal precipitation in the northern parts of India, Afghanistan, and Pakistan.

On average, annual snowmelt contributes approximately 23% of the flow of the 12 major river basins that originate high in the HKH and flow downstream to farmlands and cities, with snowmelt runoff from individual basins varying from 5% to 77%. 

The combination of seasonal snowmelt and glacial melt plays a key role in river hydrology and people’s daily life downstream.

In addition, snow helps sustain glaciers, while snow cover helps regulate the temperature of the earth’s surface, and variations in snow cover can affect regional weather patterns. 

The cooling associated with moist spring soils and a heavy snowpack in Eurasia is believed to shift the arrival of the summer monsoon season and influence its strength and duration.

ICIMOD’s scientists said the region overall has been experiencing extended monsoons in recent years, characterised by high and intense rainfall. The 2023 monsoon in eastern Himalaya (east Nepal, Sikkim in India, Bhutan) resulted in disastrous flooding, accompanied by numerous landslides. Further north, noticeable changes have been occurring, including a shift in precipitation phases. Areas that traditionally experienced snowfall are now seeing more frequent rain.

While the data gap is still a major concern for the region, it has become paramount to make the most of existing data and expedite the uptake of adaptive measures to mitigate future risks. Decisions on water management need to be swift in adjusting to manage flood risk as well as water needs. 

To reduce future water stress and risk, adaptive measures must focus on optimising food production and enhancing irrigation networks while promoting regional Disaster Risk Reduction strategies and leveraging the trade-off between water and food security needs.