Beginning around 12,900 years before the present, temperatures across the Northern Hemisphere dropped sharply, glaciers re-advanced, and the relatively mild conditions that had been developing across the Fertile Crescent were replaced by cold, dry, and harsh conditions that would have significantly stressed human communities adapted to the warmer post-glacial world.

The Younger Dryas lasted until approximately 11,700 years before the present, when temperatures warmed again relatively rapidly, initiating the stable warm conditions of the Holocene.

The communities that lived through the Younger Dryas were not simple or unprepared people.

The Natufian culture, which flourished in the Levant during the period before and during the Younger Dryas, represents one of the most sophisticated pre-agricultural societies known from the archaeological record.

Natufian communities built substantial semi-permanent settlements, had elaborate mortuary practices, produced ground stone tools for processing plant foods, and maintained rich symbolic and artistic traditions.