The most comprehensive survey of glaciers on the Tibetan plateau and the surrounding areas in the Himalaya, Karakoram, Pamir, and Qilian mountain ranges has found, based on study of satellite data and field measurements, that the majority of glaciers there are in rapid retreat—and over the past 30 years the rate has been increasing.
However, as previous studies have shown, there is significant regional variability, with glaciers in part of the region advancing (in the western part of the region) while others (in the central and eastern part) are retreating.The cited reasoning is similar to previous research. It comes down to local weather conditions:
“Temperature rise is important,” says Yao [Tandong]. “But its effects on glaciers also depend on climate regimes.” In places dominated by the westerlies, such as the Karakoram and the Pamir plateau, glaciers gain their mass mostly from winter snow, and so are less affected by warming because temperatures in winter are still below zero. In the eastern and central Himalayas, however, it snows mainly during monsoon season, and a slight increase in summer temperatures can affect glaciers drastically.
In the past few decades, the Indian monsoon has been getting weaker. By contrast, the westerlies are getting stronger. “This explains why most glaciers that are either stable or advancing are in the Karakoram or the Pamir plateau,” says Yao. (Nature)
Read the research: Nature Climate Change