ITS collapse was so violent that it was picked up by earthquake monitors 150 miles away - a thundering warning to the world that the Arctic was heating up faster than scientists had imagined.
A giant ice shelf, covering 41 square miles, had broken off from the Canadian mainland and floated off into the sea.
This handout photo provided by NASA shows a Modis (Moderate Resolution Imaging Spectroradiometer) Image showing the Ayles Ice Shelf collapse, center, in the early afternoon of Aug. 13, 2005. Within days of breaking free, the Ayles Ice Shelf drifted about 30 miles offshore before freezing into the sea ice.
Yet for 16 months, experts were unaware that the Ayles ice shelf - just one of six remaining in the Canadian Arctic - had drifted off until a scientist began examining old satellite images.
Yesterday, scientists said the dramatic discovery capped a year of new studies, which have revealed that the world is heating up faster than had been thought.
From the slowing Gulf Stream, to the warmest British summer on record, to unusually warm water in the Caribbean, researchers have mapped our rapidly changing climate.
Scientists were yesterday still coming to terms with the im-portance of the Ayles ice shelf collapse.
"This is a dramatic and disturbing event," said Dr Warwick Vincent, an Arctic ice expert at Laval University in Quebec.
"It shows we are losing remarkable features of the Canadian North that have been in place for many thousands of years. We are crossing climate thresholds and these may signal the onset of accelerated change ahead."
Dr Vincent added that he had never seen such a dramatic loss of sea ice, a chunk the size of the Hebridean island of Rum or 11,000 football pitches, in a decade's study of the Arctic.
He said: "It is consistent with climate change. We're not able to connect all the dots, but unusually warm temperatures definitely played a major role."
The Canadian view was backed by Dr Ian Moffatt, a Stirling University climate-change expert, who warned that the Earth appeared to be warming faster than had been thought.
Dr Moffatt called for a massive international effort to develop new, green energy sources before it was too late.
Dr Moffatt said that the Intergovernmental Panel on Climate Change (IPCC) had predicted an increase of one to five deg C over the next 50 to 100 years, but it was beginning to appear that temperature change was at the upper end of the IPCC predictions.
"This ice loss is a serious problem, because it's indicating a bigger breakdown than was predicted," Dr Moffatt said.
But there are solutions, Dr Moffatt stressed: "The key feature is we start looking at alternative energy sources, rather than just talking about it."
Dr Moffatt said the cost of developing cleaner energy could be high, but not as high as once feared. And he warned: "If we don't pay these costs, it will cost us the Earth."
Extensive ice loss could also lead to the extinction of animals such as the polar bear, Dr Moffatt predicted.
And he said that global warming could plunge Scotland into a deep freeze, because huge amounts of fresh water trapped in ice could melt into the Atlantic and kill off the Gulf Stream, which passes past the UK and Ireland and keeps the land temperature up.
Dr Moffatt explained: "If we get a large quantity of ice going into the North Atlantic and it begins to melt, salinity is reduced, it cools the sea and turns off the great ocean currents.
"We could see Edinburgh, which is on the same latitude as Moscow, becoming very cold."
Duncan McLaren, the chief executive of Friends of the Earth Scotland, said the future of the planet looked bleak - but he pointed to rays of hope in 2006.
He said: "This year will go down as the year that the vast majority of people woke up to climate change. People are now seeing the reality of climate change."
THE HEAT IS ON AS ICE MELTS AND ISLANDS VANISH
GLOBAL problems attributed to climate change in 2006 include:
INDIA: Lohachara in the Bay of Bengal, submerged by rising sea levels, was the first inhabited island to be wiped out by global warming.
UK: Britain notched up its highest average temperature since records began in 1659.
EUROPE: The skiing industry in the Alps looks bleak after the warmest successive period for 500 years.
AFRICA: The Sahara desert continues to expand, turning farmland into sand and fuelling civil war in Darfur, Sudan.
US VIRGIN ISLANDS: The Caribbean island group lost nearly half the coral reefs in study sites.
GREENLAND: Glaciers are melting, with a 250 per cent loss of ice.
AUSTRALIA: The bushfire season is starting earlier and burning more fiercely.
Copyright © 2006 The Scotsman