SciencePrehistoricGreenlandhigh confidence

Greenland ice-core samples indicate that temperatures increased by up to 10 °C (18 °F) in just a few decades at the end of the Younger Dryas.

Notes on verification

Confirmed by NOAA paleoclimatology data, Alley (2000) primary study, and corroborating peer-reviewed sources (ScienceDirect 2021, 2022). Minor variation in exact figures (5-10°C, ~12°C) across studies but core claim of abrupt ~10°C warming in a few decades is well supported. [tier=gold indep_score=0.983 clusters=3 claim_tier=notable]

Sources