Glaciers on the Tibetan plateau, which are the source of water for millions in Asia, are retreating as the temperatures on the plateau have become warmer in the past five decades than anytime in the last 2,000 years, Chinese scientists say.

And the trend is expected to continue, they say, as predicted ongoing warming through this century will see them pull back even more, leaving desert conditions in their wake.

"Over the past 50 years, the rate of temperature rise has been double the average global level," a report from the Chinese Academy of Sciences' Institute of Tibetan Plateau Research said.

Chinese scientist reported that during the last 30 years Tibetan glaciers have shrunk about 3,100 square miles, or 15 percent of their previous coverage.

If the retreat continues, water supplies in a number of Asia's major rivers -- the Yangtze and Yellow in China, the Brahmaputra in India, the Mekong of Southeast Asia -- could be threatened, the scientists said.

Around two billion people living in more than a dozen countries, almost a third of the globe's population, depend on glacier-fed rivers originating in the plateau region.

The rivers are a lifeline for some of the world's most densely populated areas.

Locals say they have witnessed the changes brought about by the retreating glaciers.

"This all used to be ice ten years ago," Tibetan farmer Jia Son says of the glacier near his village of Mingyong. "The beast is sick and wasting away. Our sacred glacier cannot survive, how can we?"

Rising temperatures along with human activity in the region could increase flooding and the possibility of landslides or avalanches, researchers say.

The Tibetan Plateau, the largest on Earth with an area larger than that of Western Europe, and its surrounding mountains are covered in the largest volume of ice found outside of the polar regions.

Glaciers are everywhere on the plateau, the highest in the world at an average altitude of above two miles. There are almost 37,000 separate glaciers flowing down Chinese side of the plateau alone.

Although the state of the plateau's glaciers remains a concern, there is some indication the region's warming temperatures have been a boost to some local ecosystems, researchers said.

Their report notes that China plans to complete dams and an accompanying hydropower system by 2020 that will support its burgeoning population, and that India has similar plans for the Brahmaputra River.