
The film "The Day After Tomorrow" was all good fiction when it came out in 2004, but now scientists are finding eerie truths to the possibilities of sudden temperature swings.
Looking ahead to the future, there is no reason why such a freeze shouldn't happen again - and in ironic fashion it could be precipitated if ongoing changes in climate force the Greenland ice sheet to suddenly melt, scientists say.
Starting roughly 12,800 years ago, the Northern Hemisphere was gripped by a chill that lasted some 1,300 years. Known by scientists as the Younger Dryas and nicknamed the "Big Freeze," geological evidence suggests it was brought on when a vast pulse of fresh water - a greater volume than all of North America's Great Lakes combined - poured into the Atlantic and Arctic Oceans.
This abrupt influx, caused when the glacial Lake Agassiz in North America burst its banks, diluted the circulation of warmer water in the North Atlantic, bringing this "conveyer belt" to a halt. Without this warming influence, evidence shows that temperatures across the Northern Hemisphere plummeted.
Comment: We can add this to the growing body of data pointing to the very real prospect of a sudden onset ice age:
Fire and Ice: The Day After Tomorow