RENO, NEVADA—An international team of scientists has analyzed more than 20 ice cores from Greenland and Antarctica and reconstructed the climate timeline for the first millennium. “Ice-core timescales had been misdated previously by five to ten years during the first millennium leading to inconsistencies in the proposed timing of volcanic eruptions relative to written documentary and tree-ring evidence recording the climatic responses to the same eruptions,” Francis Ludlow of the Yale Climate & Energy Institute told The Telegraph. The new study of ice cores, combined with historic records from around the world, suggests that two huge volcanic eruptions in North America could have caused the sixth-century dust clouds that led to widespread famine and disease in Europe, and even the fall of the Roman Empire. “Our new dating allowed us to clarify long-standing debates concerning the origin and consequences of the severe and global climate anomalies which began with the mystery cloud in A.D. 536 observed in the Mediterranean basin,” said Michael Sigl of the Desert Research Institute and the Paul Scherrer Institute.