Over 500 Glaciers Lost in Bhutan in 50 Years, Raising Alarm for Sikkim and Arunachal

A new scientific study has revealed that Bhutan has lost more than 500 small glaciers over the last five decades, highlighting the accelerating impact of climate change on the eastern Himalayas. The findings have also triggered serious concerns for neighbouring Indian regions such as Sikkim and Arunachal Pradesh, which share similar Himalayan geography and climatic conditions.

The study, published in the journal Remote Sensing, analysed glacier changes in the Bhutanese Himalaya between 1976 and 2024 using satellite imagery and historical glacier inventories. Researchers found that 524 glaciers completely disappeared during this period. Alarmingly, glacier loss intensified after 1998, with over 83 per cent of the extinctions occurring between 1998 and 2024. During this later phase, nearly 16 glaciers vanished every year, compared to about four annually in the earlier decades.

Scientists noted that smaller glaciers, especially those under five square kilometres, were the most vulnerable to rising temperatures and changing snowfall patterns. Glacier loss was also uneven, with southern Bhutan—bordering India—recording higher extinction rates than the northern region.

Experts warned that similar glacier retreat may already be underway in India’s eastern Himalayan states. A separate 2025 study had earlier reported the disappearance of 110 glaciers in Arunachal Pradesh over 32 years, reinforcing fears of widespread ice loss across the region.

Rapid glacier retreat poses serious risks to water security, river flow stability, and natural hazards.

Himalayan glaciers play a vital role in sustaining rivers during dry seasons. The study also pointed to the growing influence of glacial lakes, which accelerate ice melting and increase the risk of floods, further threatening downstream communities in Bhutan and India.