In a warming world, what could cause temperatures to suddenly plummet across the Northern Hemisphere? Scientists have tried to answer this question for decades, ever since they discovered geological and biological evidence for the “Big Freeze.”
Now, a new study points to an armada of icebergs or meltwater from Greenland as a possible cause for the sudden climate change called the Younger Dryas, or the Big Freeze. The findings were published online July 10 in the journal Earth and Planetary Science Letters.
Starting roughly 12,900 years ago, the Big Freeze halted the Northern Hemisphere’s transition from an Ice Age to today’s relatively warm, interglacial period. In just a decade, glacial cold returned to the northern latitudes. The tropics shifted more slowly, with changes in monsoon intensity and the amount of rainfall they received. Only Antarctica went untouched.