Even if the most ambitious Paris Agreement goal of limiting global warming to 1.5 degrees Celsius is achieved, one-third of the glaciers would go, according to the Hindu Kush Himalaya Assessment.
Five years in the making, the 650-page report was published by the International Centre for Integrated Mountain Development in Nepal, one of eight countries on the front line.
"This is the climate crisis you haven't heard of" said Philippus Wester, one of the scientists involved in the report.
"Global warming is on track to transform the frigid, glacier-covered mountain peaks... cutting across eight countries to bare rocks in a little less than a century" he said in a statement.
Speaking to RFI, he explains that "what we're seeing around the world in mountains is that it gets hotter faster than the global average. So even 1,5 degrees, a very ambitous target if we achieve that, it will still be too hot in these moutains, because two degrees is the climate threshold."
Glaciers vital life source
Glaciers in the Hindu Kush-Himalaya region are a critical water source for some 250 million people in the mountains as well as to 1.65 billion others in the river valleys below, the report says.
The glaciers feed 10 of the world's most important river systems, including the Ganges, Indus, Yellow, Mekong and Irrawaddy, and directly or indirectly supply billions of people with food, energy, clean air and income.
Impacts on people from their melting will range from worsened air pollution to more extreme weather.
Lower pre-monsoon river flows will throw urban water systems and food and energy production off-kilter, the study warns.