Thirty reference glaciers monitored by the Swiss-based World Glacier Monitoring Service lost about 66 centimetres (two feet) in thickness on average in 2005, the UN Environment Programme said in a statement.

"The new data confirms the trend in accelerated loss during the past two and a half decades," it added.

The set of glaciers located around the world have thinned by about 10.5 metres (34.6 feet) on average since 1980, according to the data supplied by the Monitoring Service in Zurich.

They melted on average about 1.6 times faster annually this decade compared with the 1990s, and about six times faster than in the 1980s.

The glacier surface area is also much smaller than in the 1980s, said Michael Zemp, a glaciologist at the Monitoring Service.

"The recent increase in the rates of ice loss over reducing glacier surface areas leaves no doubt about the accelerated change in climatic conditions," Zemp added.

UNEP Executive Director Achim Steiner said: "The findings confirm the science of human-induced climate change."

Steiner said the data from glaciers provided "confirmation that will be further underlined when the Intergovernmental Panel on Climate Change unveil their next report on February 2."

The world's top climate experts began a four-day meeting of the UN panel on Monday in Paris, where they are set to launch a long-awaited update about the scientific evidence for global warming later this week.

The melting of the mountain ice floes is expected to show up in 2006 data because it was one of the warmest years in many parts of the world, UNEP said.

"These findings should strengthen the resolve of governments to act now to reduce greenhouse gas emissions and put in place the medium to longer term strategies necessary to avert dangerous climate change," Steiner said.

The UN's environmental chief underlined the importance of glaciers for human life in many regions.

"Glaciers across the globe are important sources of water for many rivers -- rivers upon which people depend for drinking water, agriculture and industrial purposes," he said.

The preliminary 2005 data was based on readings from 30 of the 80 monitored glaciers, which have had continuous measurements since the 1980s.

The average annual ice loss since 2000, repeated in 2005, was about 0.6 metres of water equivalent, a scientific measurement used by glaciologists. On average, one metre water equivalent corresponds to ice about 1.1 metres thick, according to the statement.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.