By Anna Pujol-Mazzini

LONDON, Sept 14 (Thomson Reuters Foundation) - Asian glaciers are set to shrink by at least a third by 2100 due to climate change, researchers said on Thursday, threatening millions who depend on their meltwaters for drinking, farming and hydro-electricity.

The scientists' prediction is based on an assumption the world will limit global temperature rises to 1.5 degrees Celsius above pre-industrial levels - although many expect Earth will be much hotter than this by the end of the century.

"As we have already considerably warmed the earth since the industrial era, we have caused an imbalance of the glaciers," said Philip Kraaijenbrink, the study's author and a geography researcher at Utrecht University in the Netherlands.

"We observe their retreat almost everywhere on the globe. Even if we (do) not warm the climate any more at all, starting today, 14 percent of the ice will be lost," he told the Thomson Reuters Foundation.

Under the Paris climate accord, countries pledged to keep the rise in average global temperatures below 2 degrees Celsius above pre-industrial levels to stave off the worst effects of climate change.

But scientists say there is a 90 percent chance this target will not be met as temperatures are already 1.2 degrees Celsius above pre-industrial times, according to the World Meteorological Organization.

More than one billion people across Asia depend on rivers like the Yangtze, Ganges and Mekong, which are fed by Himalayan glaciers. Snowfall provides moisture for farms and pastures and melts into rivers and streams.

If limited efforts are made to prevent climate change and the world reaches a 4 degree Celsius rise, the glaciers could shrink by as much as two-thirds by 2100, the study found.

For each degree of global warming avoided, 7 percent of ice in Asian glaciers would be saved, researchers said.

Asian glaciers are warming faster than the rest of the planet and are already about 2 degree Celsius above pre-industrial levels, they said.

(Reporting by Anna Pujol-Mazzini @annapmzn, Editing by Katy Migiro. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters that covers humanitarian news, women's rights, trafficking, property rights, climate change and resilience. Visit http://news.trust.org)