India's glaciers, including one that feeds Ganga, are melting

Hyderabad: Almost all of India’s glaciers — the ice reservoirs built over tens of thousands of years – in the Himalayas are melting, according to the central government. Acknowledging the “increasing threats posed by the climate change” in the Himalayan region, the ministry of Jal Shakti on Thursday said a “majority of Himalayan glaciers are observed to be melting or retreating at various rates in different regions.”

It further said “as glaciers retreat, the long-term reduction in melt-water will likely lead to decreased flow in rivers during the dry seasons. The Himalayas serve as a critical water source for major river systems like the Ganga, Brahmaputra, and Indus,” the ministry said.

According to Union minister of state for Jal Shakti Raj Bhushan Choudhary, India has 9,575 glaciers, small and big, with the highest number of 5,262 in Ladakh, Jammu & Kashmir, while the fewest, 161, are in the Himalayas in Arunachal Pradesh.

Among the glaciers that are melting, and at a fairly rapid rate, is Gangotri in Uttarakhand, which the minister said in a reply to a question from Asaduddin Owaisi, the Lok Sabha member from Hyderabad who sought to know the status of India’s glaciers, and impact of any changes in them. The Ministry said that as per a study of glacial melt between 1935 and 1996, by Geological Survey of India, Gangotri glacier has been melting at a rate of 18.8 metres.

Later research by scientists studying Himalayan ecology in their study, “Frontal Changes of Gangotri Glacier, Garhwal Himalaya, between 1935 and 2022”, established that Gangotri’s melt rate has increased and by 2022, it has been losing around 34 metres of its length every year. Another glacier, Satopanth, which along with Gangotri is the primary contributor of ice melt water of Ganga river, too has been facing increasing melt rates, other studies have found.

The minister said initially, glacial melt may cause increased water flow, but as glaciers shrink, this contribution declines, leading to shortages, especially in the summer months.

One of the major immediate impacts are glacial lake outburst floods (GLOFs) that occur when glacial lakes, formed by the melting water, break and cause severe, sudden floods in downstream areas. It may be recalled that one such GLOF incident in Uttarakhand in 2021 after a glacial lake formed by the melting Nandadevi glacier, destroyed the under construction Tapovan hydro electric station resulting in the death of around 150 workers, and forced the government to take up intensive monitoring of glacial lakes, and some immediate glacial ecology in Uttarakhand

Reduced glacier melt impacts freshwater ecosystems by changing river flow patterns, temperature, and sediment load. These in turn, affect aquatic species' habitats and can lead to shifts in biodiversity. Choudhary also said long-term impacts may include migration or shifts in livelihoods.

“Many Himalayan communities have deep spiritual connections to glaciers, rivers, and mountains, and the retreat of glaciers can have profound cultural and religious consequences from the cascading effect of glacial retreat,” he said.

Important Information

Some glaciers and their retreat rates

Dokriani Glacier in the Bhagirathi Basin: 15-20 meters per year since 1995;

Chorabari Glacier in the Alaknanda Basin: 9-11 meters per year between 2003 and 2016;

Pensilungpa Glacier in the Western Himalayas: Lost around 2,941 meters, averaging 5.6 meters per year, from the Little Ice Age (between 14th and 19th centuries) until 2019;

DurungDrung Glacier in Ladakh: 12 metres per year between 1971 and 2019.

Parkachik Glacier in Ladakh: 4.21 meters per year between 1971 and 2021.

India’s glaciers

State – Number – Area*

Jammu & Kashmir/Ladakh – 5,262 – 29,163

Himachal Pradesh – 2,735 – 4,516

Uttarakhand – 968 – 2,857

Sikkim – 449 – 706

Arunachal Pradesh – 161 – 223

*in sq km