Glaciers melting at Zanskar valley could havealarming impact on climate change: LU study

Lucknow: The mighty glaciers of the Zanskar Himalaya, Ladakh, Durung-Drung (DDG) and Pensilungpa (PG), are retreating at an alarming pace, painting a stark picture of climate change in India's high mountains.

A recent study conducted jointly by the Wadia Institute of Himalayan Geology and Lucknow University has tracked these glaciers between 2015 and 2023, revealing a significant loss of ice mass and an expansion of glacial lakes that threaten both ecosystems and human settlements downstream. The research highlights that the retreat rate of these glaciers has doubled in the last eight years and was recently published in the peer-reviewed international journal Environmental Monitoring and Assessment.

The Durung-Drung Glacier, stretching nearly 23 kilometers long, has retreated by about 165 meters in just eight years. This translates to an average retreat rate of 21 meters per year, almost double the 12 meters per year recorded before 2015. Scientists also found that the glacier was once 350 meters thicker, as indicated by ancient moraine deposits now exposed along its flanks.

Similarly, the Pensilungpa Glacier has retreated by around 80 meters between 2015 and 2023, with its retreat rate nearly doubling from 5–6 meters to about 10 meters per year. Geological evidence suggests that this glacier was previously 170 meters thicker than its current state.

As the glaciers shrink, nearby lakes are expanding rapidly. Proglacial lakes in front of DDG have grown by 164% in area and 190% in water volume between 2004 and 2023, while periglacial lakes near Pensila Pass have expanded by 6.5% in area and 7% in volume. This rapid swelling of glacial lakes raises serious concerns about the potential for glacial lake outburst floods (GLOFs), sudden, catastrophic events that can devastate downstream valleys.

Experts attribute this accelerated melting to a combination of factors, including rising temperatures, declining snowfall, and longer summers in high-altitude zones. Dust and soot deposits from vehicles and industrial emissions darken glacier surfaces, increasing heat absorption. Changing precipitation patterns, where rain increasingly replaces snow, are hastening the melting process.

According to Vinit Kumar, associate professor, department of geology, Lucknow University, who also worked as scientist at the Wadia Institute of Himalayan Geology, Dehradun, and part of the research team, said, "What we are witnessing in Zanskar is not an isolated event. It's part of a broader Himalayan trend. Without immediate mitigation, the loss of these glaciers will have cascading effects on water availability, agriculture, and disaster vulnerability."

Researchers recommend urgent measures such as reducing pollution and vehicular emissions, continuous glacier monitoring through satellite and field studies, and installing early warning systems to detect potential lake outburst floods. Engaging local communities in conservation and awareness initiatives is also essential to mitigate future risks.