The retreat of Himalayan glaciers will never stop; what we can only hope for is to slow the decline

The Himalayas are reaching a critical point where fragile mountains with unstable slopes, and rapidly retreating glaciers are triggering disasters to become increasingly frequent and severe. Since the 2013 Kedarnath tragedy, catastrophic events have become more common, yet action plans at the policy levels to mitigate disasters are still missing despite plenty of scientific studies and reports.

The Himalayas are the youngest mountains in the world. The young and fragile mountains are naturally prone to landslides, while extreme weather events such as rising temperatures, erratic rainfall, and cloudbursts trigger floods and debris flows. Illegal human activities like unplanned construction, deforestation, and road widening further weaken the slopes. Above all, melting glaciers are creating unstable lakes that heighten the risk of sudden outburst floods, turning the Himalayas into one of the most disaster-prone regions in the world.

For thousands of years, the Himalayas, covered with glaciers and snow, have maintained a natural balance of water and ecology. But today, accelerated glacier retreat is disturbing this balance, making downstream communities more vulnerable.

In the Western Himalayas, until the 2000s, many of the glaciers were retreating while others were advancing. However, glacier retreat has become the dominant characteristic climate change impacted feature in the Western Himalayas, especially since the 2000s especially high in Sikkim and Arunachal Pradesh. Until recently, scientists and policy makers did not have enough data from these regions. However, it has been found that there are more than 150 glacial lakes in Arunachal Pradesh.

What is also worrying is that Glacial Lake Outburst Floods (GLOFs) are becoming more common in the Himalayas as retreating glaciers leave behind unstable lakes held by weak moraine dams that generally protect glacial lakes. Even small triggers such as heavy rainfall, avalanches, or landslides can unleash sudden and destructive floods to downstream communities. At the same time, we are also beginning to see signals of permafrost melt (thaw) in the higher Himalayas, an area with significant data and research gaps that needs to be addressed. Permafrost, which means ground frozen for at least two years, develops an “active layer” that melts and refreezes seasonally. Variations in this layer can lead to thawing like what we observe in the Arctic and other glaciated regions. This process loosens rocks, destabilises slopes, and increases landslide and rockfall risks. Together, GLOFs and permafrost thaw illustrate how rising temperatures are reshaping the fragile Himalayan landscape and amplifying disaster risks for vulnerable mountain communities.

As a scientist, I primarily rely on remote sensing data to study Himalayan glaciers, from historical, present and forthcoming satellite products. Our results show that glacier loss since 2000 is almost four times higher than in the previous century. We also conduct field campaigns to validate these findings, where we observe real-time signals such as clear moraine imprints marking past glacier extents, expanding glacial melt ponds, and uneven debris cover that accelerates retreat. During these visits, our primary source of information is Indigenous Knowledge from the local communities. When I visited Badarinath in the Chamoli district in Uttarakhand recently, I interacted with the people there. They told me that when they were kids, they could see a glacier from their house, and now it has retreated by kilometres. The loss of solid precipitation is not something to celebrate, as we need it for restoring glacier health These changes are strong indicators of climate change, in line with Intergovernmental Panel on Climate Change (IPCC). The IPCC 6th Assessment Report has reported that if the global temperature exceeds above 1.5°C, then the Himalayan glaciers will rapidly melt and will be in peril affecting more than 2 billion people directly and indirectly Studying glaciers on the ground, however, is extremely logistically challenging due to the high elevations, harsh climate, and difficult terrain, which restrict detailed studies to only a few sites. This is why better satellite-based monitoring, with regular temporal coverage and a comprehensive regional database of potentially dangerous glaciated zones, is urgently needed to guide adaptation and mitigation strategies. We also need to have better data sharing policies in place for scientists.

We all know climate change is real, and the frequent disasters in the Himalayas are a living proof of it.  Even if we take strong climate action now, glaciers will continue to retreat for decades because warming is irreversible. The glacier retreat cannot stop but what we can hope for is to slow the rate of loss, stabilise remaining glacier systems, and give both people and ecosystems more time to adjust.

Enough awareness has been raised. What we need now are concrete action plans. The first step for the Himalayas is to move toward sustainable development, ensuring careful planning of roads, hydropower stations, and tourism, while also strengthening disaster preparedness and early warning systems. Protecting forests, restoring watersheds, and integrating indigenous knowledge with modern science will also help communities adapt. We need to encourage community climate leaders locally.

If we do not act quickly, the future holds greater risks for mountain communities. Scientists, policymakers, and local people must work together combining indigenous knowledge with modern science to build resilience and reduce these impacts.

Remya SN is Assistant Professor at the School of Climate Change and Sustainability, Azim Premji University, Bangalore

Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth