It took just six months for a warm and sunny Europe to be engulfed in ice, according to new research.
Previous studies have suggested the arrival of the last Ice Age nearly 13 000 years ago took about a decade – but now scientists believe the process was up to 20 times as fast.
In scenes reminiscent of the Hollywood blockbuster The day After Tomorrow, the Northern Hemisphere was frozen by a sudden slowdown of the Gulf Stream, which allowed ice to spread hundreds of miles southwards from the Arctic.
Geological sciences professor William Patterson, who led the research, said: “It would have been very sudden for those alive at the time. It would be the equivalent of taking Britain and moving it to the Arctic over the space of a few months.”
Professor Patterson’s findings emerged from one of the most painstaking studies of climate changes ever attempted and reinforce the theory that the earth’s climate is unstable and can switch between warm and cold incredibly quickly.
His conclusions, published in New Scientist, are based on a study of mud deposits extracted from a lake in Western Ireland, Lough Monreagh – a region he describes as having the ‘best mud in the world in scientific terms’.
Professor Patterson used a precision robotic scalpel to scrape off layers of mud just 0.5mm thick. Each layer represented three months of sediment deposition, so variations between them could be used to measure changes in temperature over very short periods.
He found that temperatures had plummeted, with the lake’s plants and animals rapidly dying over just a few months.
The subsequent mini Ice Age lasted for 1 300 years and was probably caused by the sudden emptying of Lake Agassiz in Canada, which burst its banks and poured freezing freshwater into the North Atlantic and Arctic Oceans.
That would have disrupted the Gulf Stream – the flows of which depend on variations in saline levels and temperature – and allowed the ice to take hold.
Some scientists believe that if the Greenland ice cap melts it could disrupt the world’s ocean currents and have a similarly dramatic effect. –
via News – Science: Last Ice Age took just six months to arrive.