"It is amazing what huge masses of ice have been lost," he told Reuters in a telephone interview. "Every hiker in the Alps knows about it: the changes in recent years have been dramatic."

While Swiss glaciers shrank a meager one percent in the 12 years to 1985, they lost some 18 percent of their area in the 1985-2000 period, the research showed.

This suggests they are melting faster than earlier estimates which put the loss at 30 percent between 1980 and 2025.

Paul says that while a pattern of advancing and retreating glaciers was normal, temperature increases over the 1990s have stripped away swathes of ice which are needed to retain water, and in turn support plant and animal life in the mountains.

Last year's European summer heatwave, which caused deaths and droughts across the continent, capped more than a decade of rapid melting.

"Summer 2003 was the death blow for many small glaciers," Paul said.

"When glaciers are in the retreating phase they normally lose about 30 centimeters of snow and ice a year. In the 1990s they lost about 70 centimeters a year; in 2003, they lost 3 meters," Paul said.

Mountainous regions will become more hazardous, Paul said, because the heavy summer thunderstorms symptomatic of climate change will fall on craggy mountainsides rather than insulating layers of snow and ice, likely causing more flash floods.

Over the past 150 years, Paul said air temperatures in the Alps have warmed up by 1.2 degrees -- and could gain as much as 2-4 degrees more by the year 2100.

Many scientists blame rising global temperatures on the greenhouse effect, in which certain gases in the atmosphere, including man-made pollutants, trap heat.

The changes could also impact tourism, a crucial pillar of the Swiss economy, as the country's scenic glacial valleys become barren and rocky. Summer glacier skiing -- a popular trend particularly over recent years -- could become unfeasible, while the winter ski season shrinks along with the snow line.

"The major glaciers will probably be OK for the next 10, 20 years or so, but the real change is in the smaller, inaccessible ones and we can already see the impact," said Paul.