THIMPHU: At more than 5,000 metres above sea level, Wakila in Laya is where Dorji herds his yaks across vast alpine pastures, following a way of life passed down through generations.
For centuries, these high-altitude grasslands have served as a summer refuge for yak herders like Dorji and other highlanders, who migrate to the cooler pastures to escape the warmer valleys below.
The cold, open landscapes of Wakila have long provided reliable grazing grounds that sustain both their yaks and their traditional way of life.
But the mountains that shaped this traditional way of life are changing. Rising temperatures and shifting landscapes are disrupting seasonal cycles, forcing yak herders to adapt as centuries-old migration patterns begin to change.
“I started herding yaks when I was 15 years old, and I have seen how the mountains have changed,” said Dorji, who is now 36. “Earlier, yak herders would move to Wakila in July, when temperatures in Laya became uncomfortable for yaks. Today, we leave as early as June because Laya itself has become warmer.”
The return journey has also shifted.
Previously, families would descend to Laya in September. Now, they often remain in Wakila until October.
“Even in Wakila, during the summer months, we no longer need the heavy layers of clothing or thick coats that the biting cold once demanded,” Dorji said.
For him, the future is uncertain. If warming continues, he fears yak herders may have to search for new pasturelands further north in the future.
The changes Dorji describes are consistent with scientific findings on Bhutan’s changing climate.
A warming mountain
Bhutan has warmed by around 0.3°C to 0.5°C in recent decades, while rainfall patterns have become increasingly unpredictable, according to the country’s first Climate Atlas covering the period from 1996 to 2025.
The warming trend is part of a broader global change.
According to the World Meteorological Organisation’s (WMO) State of the Global Climate 2025 report, the global mean near-surface temperature in 2025 was around 1.44°C above the 1850–1900 baseline. The WMO’s analysis of eight global datasets found that 2025 ranked among the warmest years in recorded history.
In the Himalayas, where glaciers exist close to the threshold between freezing and melting, even small increases in temperature can have significant consequences.
Bhutan’s latest scientific assessments show that the country’s glaciers are continuing to retreat.
The Bhutan Glacier Inventory 2026, the third comprehensive national assessment of the country’s glacier resources, identified 673 glaciers covering 571.86 square kilometres across the northern mountains.
Compared with the Bhutan Glacier Inventory 2018, which recorded 700 glaciers covering 629.55 square kilometres, Bhutan has lost 27 glaciers and 57.69 square kilometres of glacier area over nine years.
This represents a 9.16 per cent reduction in glacier area between 2016 and 2025.
Tracking the disappearing ice
The latest inventory uses advances in satellite technology and artificial intelligence to map Bhutan’s glaciers more accurately.
The results show that glacier loss is occurring across most of the country’s major river systems.
The majority of the country’s glacier area remains concentrated between 5,000 and 5,700 metres above sea level, similar to previous assessments. However, the overall trend is clear, ice mass is declining.
A separate recent assessment of Bhutan’s glacial lakes also highlights the growing importance of monitoring high-altitude water bodies formed as glaciers retreat.
As glaciers melt, water can accumulate behind unstable natural barriers of rock, sediment and ice, creating risks of glacial lake outburst floods.
For communities living downstream, disappearing ice is not only an environmental concern. It is also a question of safety, water security and livelihoods.
The rivers that begin with ice
Bhutan’s glaciers are natural reservoirs. They store water in the form of snow and ice, releasing it gradually into rivers that support agriculture, ecosystems and hydropower generation.
The glaciers mapped in the 2026 inventory are distributed across three major river basins: Wangchhu, Punatsangchhu and Manas, divided into nine sub-basins.
The Punatsangchhu basin remains the country’s most glacier-rich basin, containing 328 glaciers covering 336.23 square kilometres.
The Phochhu sub-basin alone contains 200 glaciers covering 232.49 square kilometres, the highest glacier concentration in the country.
These glaciers are closely connected with communities in the highlands and valleys below. Rivers originating in these mountains provide water for farming, settlements and hydropower projects.
However, the relationship between glaciers and water is changing.
In the short term, faster melting can increase river flows. But as glaciers continue to lose mass, the long-term availability of glacier-fed water becomes uncertain.
For farmers, this could mean changes in irrigation patterns and increasing pressure on water resources. For hydropower, which depends on reliable river flows, changing water availability presents another challenge.
Changes across the country’s river basins
The Manas basin is the second most glacierised basin, with 302 glaciers covering 204.85 square kilometres.
It includes the Mangdechhu, Chamkharchhu, Kurichhu and Dangmechhu sub-basins.
Mangdechhu contains the largest glacier in the basin, covering 40.32 square kilometres.
Interestingly, the latest inventory recorded an increase in the number of glaciers in Mangdechhu. However, researchers explain that this does not indicate glacier growth. Instead, larger glaciers are breaking apart into smaller ice bodies as they thin and retreat.
The Wangchhu basin contains fewer glaciers, with 43 glaciers covering 30.79 square kilometres, but its rivers are important for some of the country’s most populated areas.
Pachhu contains the largest share of glaciers in the basin, including the Jichudrake glacier, which covers nearly nine square kilometres.
A future shaped by adaptation
For generations, Bhutanese communities have lived according to the natural cycles of nature. Yak herders followed seasonal routes, farmers understood rainfall patterns, and communities relied on rivers that flowed according to familiar cycles.
However, changing climate is disrupting these relationships.
In Wakila, Dorji’s shift in the timing of seasonal migration is a response to a wider challenge facing Himalayan communities, as warmer temperatures alter pasturelands and traditional ways of life.
These changes extend beyond remote highlands, affecting rivers, agriculture, hydropower and the safety of those living downstream.
The Bhutan Glacier Inventory 2026 provides a scientific baseline for understanding how glaciers are changing across the country. Combined with glacier monitoring, climate data and local knowledge, it helps reveal the scale of these changes and the challenges ahead.
For Dorji, however, these changes are not just figures on a report. The shrinking ice around Wakila is a landscape he has watched transform over a lifetime, a memory disappearing before his eyes. - Kuensel/ANN
