Scientists report that the world's mountain glaciers continue to melt at an accelerating rate. As we hear from VOA's David McAlary in Washington, global warming could cause most to disappear in a few decades.

There are more than 67,000 glaciers around the world in many different kinds of frigid landscapes. New data from 30 key glaciers in nine mountain ranges show that they are shrinking at ever faster rates, confirming the two-and-a-half-decade-old trend of accelerated ice loss.

"Glaciers in the mountain areas are the clearest natural indicator of climate change," said Wilfried Haeberli, director of the World Glacier Monitoring Service in Zurich, Switzerland, which has issued the latest glacier data jointly with the United Nations Environment Program.

"If we look at the mountains, we see the changes going on and accelerating," he said. "We especially also see equilibrium conditions that are being disturbed. We go more and more away from conditions we have known from the past and we enter new conditions that really are rather unknown to us and very, very difficult to foresee."

The latest glacier findings are based on measurements taken in 2005. They reveal that the 30 reference glaciers have lost an average of about two thirds of a meter thickness per year since 2000.

The World Glacier Monitoring Service says this is about 1.5 times the rate of thinning that occurred during the 1990s and three times the rate of the 1980s. The total average thickness loss of these long mountain ice flows has been nearly 10 meters since 1980.

Glaciers are Earth's biggest reservoir of fresh water and second only to the oceans in the amount of water they contain. They feed many rivers, and the U.N. Environment Program says their decline reduces the amount of fresh water for drinking, farming, and industrial purposes. Their shrinkage also contributes to sea level rise with the potential to threaten coastal and island regions.

Haeberli says the figures from 2006 are not yet available, but since it was one of the warmest years in many parts of the world, he expects them to show that the trend in glacier melt will continue.

"The glaciers we measure are relatively small and may disappear within a few decades," said Haeberli.

The glacier information is among the environmental data considered by the United Nations Intergovernmental Panel on Climate Change, now meeting in Paris before it issues its latest global warming predictions on Friday.