Claims › Younger Dryas & the 12,000-year cycle › An abrupt cold snap, the Younger Dryas, hit about 12,900 years ago
An abrupt cold snap, the Younger Dryas, hit about 12,900 years ago
The claim: As the last Ice Age was ending, the Northern Hemisphere plunged back into near-glacial cold for about 1,200 years, then warmed abruptly 11,700 years ago.
Why this label: Recorded in Greenland ice cores, lake sediments and cave deposits worldwide. The end of the Younger Dryas defines the start of the Holocene, formally dated to 11,700 years before 2000 CE (±99 years). The cause is debated; the event is not.
Background
Sea level was rising fast as ice sheets melted, with a pulse of 40 mm a year or more about 14,500–14,000 years ago. The rise paused during the Younger Dryas, then resumed. Göbekli Tepe was built soon after the cold ended. The mainstream explanation for the cooling is a slowdown of Atlantic ocean circulation after meltwater floods; alternatives include a volcanic trigger and a cosmic impact.
What has been measured
Dates, measurements and documented findings, kept separate from interpretation.
Evidence and arguments for
- Independent ice-core, lake and cave records agree on timing and abruptness. [1]
Evidence and arguments against, or limits
- Not disputed as an event; regional size and exact onset timing vary between records. [1]
Open questions & what would change the label
What triggered the cooling.
Sites
Related claims
Sources
- Walker, M. et al. (2009). Formal definition and dating of the GSSP for the base of the Holocene using the Greenland NGRIP ice core. Journal of Quaternary Science 24. doi:10.1002/jqs.1227 data
- Lambeck, K. et al. (2014). Sea level and global ice volumes from the Last Glacial Maximum to the Holocene. PNAS 111. doi:10.1073/pnas.1411762111 data
More in this section: Younger Dryas & the 12,000-year cycle.
Sources checked against Crossref and publisher pages on 2026-10-22. Labels describe the claim, not the people who hold it. Methodology.