Centennial-Scale Holocene Climate Variability Revealed by a High-Resolution Speleothem δ ¹⁸ O Record from SW Ireland

Abstract

Evaluating the significance of Holocene submillennial delta18O variability in the Greenland ice cores is crucial for understanding how natural climate oscillations may modulate future anthropogenic warming. A high-resolution oxygen isotope record from a speleothem in southwestern Ireland provides evidence for centennial-scale delta18O variations that correlate with subtle delta18O changes in the Greenland ice cores, indicating regionally coherent variability in the early Holocene. Evidence for previously undetected early Holocene cooling events is presented, but mid- to late-Holocene ice rafting in the North Atlantic appears to have had little impact on delta18O at this ocean margin site.