Map of Evidence (IMAGE) Ohio State University Caption The locations of ice cores and evidence for abrupt climate change approximately 5,000 years ago discussed in the research are shown, along with areas of large-scale ice retreat. Credit Courtesy of Lonnie Thompson, Ohio State University. Usage Restrictions News media only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.