TROMSOE (Norway) - NOBEL prize climate champion and former US vice-president Al Gore called Tuesday for rapid action to prevent the potentially irreversible melting of the planet's ice, just months before a UN climate summit.

'This conference is a global wake-up call,' Mr Gore said, adding: 'The scientific evidence for action in Copenhagen in December is continuing to build up week by week.' He explained why the melting ice posed such a threat to the planet.

'Ice is important through the ecological system of the Earth for many reasons, but one of them has to do with its reflexivity,' he said.

Ice reflects 90 per cent of the sun's radiation back into the atmosphere. If the ice were to melt, the dark water would not reflect the heat but instead absorb it, thereby accentuating the effect of global warming.

'As it disappears we have to keep in mind that it can come back only if we act fairly quickly,' said Mr Gore, who shared the 2007 Nobel Peace Prize with the UN's Intergovernmental Panel on Climate Change.

He explained that 'if we keep turning the temperature of the Earth up, then the heat will go to lower depths of the Arctic Ocean and it will be impossible for the ice to come back.'

The Arctic ice cap measured 4.13 million sq km in September 2007, its smallest size ever. It is also thinner than ever, making it more susceptible to rapid melting.

Ice melting in the Antarctic and Greenland as well as on the world's glaciers will also have dramatic consequences, Mr Gore said, warning that each one-metre rise of water levels will cause 100 million people to become climate refugees.

Melting snow in the Himalayan mountain range, dubbed 'the third pole', will meanwhile lead to flooding, then droughts, for 40 per cent of the planet's population which depends on that water for survival. -- AFP