Centennial-scale holocene climate variability revealed by a high-resolution speleothem delta O-18 record from SW Ireland

Evaluating the significance of Holocene submillennial delta O-18 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 delta O-18 variations that correlate with subtle delta O-18 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 delta O-18 at this ocean margin site. (Author)