Younger Dryas: Rapid Climate Reversal 12,900 Years Ago Resumed Glacial Conditions. Younger Dryas was a severe climate catastrophe affecting the Northern Hemisphere Began approximately 12,900 years ago Interrupted the post-glacial warming period that had begun after the last glacial maximum

About 12,900 years ago, the Younger Dryas slammed the Northern Hemisphere with a severe climate catastrophe, abruptly halting post-glacial warming that had begun after the last glacial maximum. Associated with rapid meltwater pulses, sea levels fluctuated dramatically — dropping up to 400-500 feet during glacial periods then rising rapidly during deglaciation, sometimes exceeding present levels. ❄️🌊

Key Facts

  • Younger Dryas was a severe climate catastrophe affecting the Northern Hemisphere
  • Began approximately 12,900 years ago
  • Interrupted the post-glacial warming period that had begun after the last glacial maximum
  • Associated with rapid meltwater pulses including Meltwater Pulse 1A and Meltwater Pulse 1B
  • Sea levels dropped up to 400-500 feet during glacial periods
  • Sea levels rose rapidly during deglaciation, sometimes to levels higher than present day
  • The Younger Dryas effect on human populations will be addressed in upcoming episodes