
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...