The Cores Tell the Story (image) Brown University Caption Sedimentary cores taken from the ocean floor in four locations show that climate patterns in the tropics have mirrored Ice Age cycles for the last 2.7 million years and that carbon dioxide has played the leading role in determining global climate patterns. Cores from site 806 were used as controls. Credit Timothy Herbert, Brown University Usage Restrictions None 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.