Younger Dryas

The Younger Dryas was an abrupt cold reversal during the last deglaciation, roughly 12,900 to 11,700 years ago, that interrupted the warming out of the last glacial period. Greenland temperatures dropped by up to about 10 degrees C within decades. The leading explanation is a freshwater pulse, plausibly from glacial Lake Agassiz or Arctic routing, that capped North Atlantic Deep Water formation and weakened the AMOC, cutting the northward ocean heat transport. The termination near 11,700 years ago was equally sharp and marks the start of the Holocene.