Glaciers across the Asian highlands are disappearing at an alarming rate, losing more than 22 gigatons of ice annually, equivalent to the volume of 9 million Olympic-sized swimming pools.

While scientists have long linked this loss to global temperature rise, new research from the University of Utah and the University of Virginia shows that changes in seasonal weather patterns also play a significant role.

The study, which provided the first clear evidence that shifts in rainfall and snowfall caused by the South Asian monsoon accelerate ice melt, found that regions such as the central, western, and eastern Himalayas are particularly at risk.

Sonam Sherpa, assistant professor at the University of Utah and lead author of the study, warned that continued changes in the timing and intensity of the monsoon could speed up ice loss and threaten water supplies for millions along the river basin.

The region, often called the “Third Pole,” contains the largest frozen ice reserve outside the North and South Poles. Its glaciers feed rivers and lakes that provide fresh water to over 1.4 billion people in South and Central Asia, supporting agriculture, hydropower, and essential drinking water.

In the central Himalayas, many glaciers gain mass during the summer monsoon rather than winter. At high altitudes, cold air turns heavy rainfall into snow that preserves the ice. But global warming disrupts this balance by reducing snowfall and shortening the precipitation season, sometimes turning snow into rain. With less accumulation and more melting, glaciers are retreating at an accelerated pace.

Researcher Susanna Wirth, assistant professor at the University of Virginia Tech and co-author of the study, warned that the rapid retreat of mountain glaciers will shift the main river flow source from ice melt to rainfall, increasing drought risk along the river basin in coming generations.

The risks are not limited to long-term water loss; faster melting also raises the danger of glacial lake outburst floods, which have become more common in mountainous areas as glaciers retreat under warming climates.

These sudden floods can trigger cascading hazards such as landslides and river floods, potentially destroying nearby communities.

Scientists relied on satellite data from NASA’s GRACE mission, which tracks changes in Earth’s gravity field to detect ice mass loss. They found that glaciers in the central and western Himalayas lose ice due to increased rainfall, while in the east, reduced snowfall plays a bigger role.

The study also identified melt cycles of 3 to 8 years linked to natural monsoon variability, raising concerns about how future climate shifts will affect glacier stability.