"Increasing global temperatures in the coming century will cause continued widespread melting of glaciers, which contain 70 percent of the world's fresh water reserves," it warned in a new study.

"An overall rise of temperature of four degrees Celsius before the end of the century would eliminate almost all of them," it said.

Average temperatures have risen between 0.6 and 0.7 degrees Celsius since 1860, according to WWF, which urged countries to curb emissions of carbon dioxide to ensure the increase stays well below a threshold of two degrees.

The Switzerland-based conservation group released its study on climate change and global glacier decline in Milan where more than 180 countries are due to gather from December 1-12 for the UN Climate Change Convention to assess progress in addressing problems concerning global warming.

"The melting of glaciers will lead to water shortages for billions of people, as well as sea levels rising and destroying coastal communities worldwide," WWF said.

Ecuador, Peru and Bolivia, where major cities rely on glaciers as their main source of water during dry seasons, would be worst affected, it predicted.

In the Himalayas, there was a grave danger of flooding, the group said, noting that glacier-fed rivers in the region supply water to one third of the world's population.

"Glacial meltdown is a clear sign that we must act now to fight global warming and stop the melting," said Jennifer Morgan, director of WWF's climate change programme.

The environmental organisation called on the ministers who will attend the Milan conference to act faster to combat global warming, urging those from developing nations in particular to demonstrate their will to tackle the issue.

WWF wants strong rules governing the use of forests, which play a vital role in absorbing carbon dioxide.

The group also asked governments to ensure Russia ratifies the 1997 Kyoto Protocol, which establishes a set of goals to reduce greenhouse gas emissions.

Already ratified by 119 countries, the text just needs a commitment from Moscow to become international law, it said.

On Tuesday, Italian officials said the European Union has pledged 390 million dollars (325 million euros) a year to help developing countries from 2005 fight the damaging effects of climate change.

In 2001, 20 countries including the 15 EU members pledged to provide 410 million dollars annually to poorer countries until 2005.

SPACE.WIRE