Coupling of CO 2 and Ice Sheet Stability Over Major Climate Transitions of the Last 20 Million Years

• Published in: Science
• Main Authors: Tripati, Aradhna K., Roberts, Christopher D., Eagle, Robert A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2009
• Subjects: Ice Sheet; Planktonic foraminifera
• Online Access: http://dx.doi.org/10.1126/science.1178296; https://www.science.org/doi/pdf/10.1126/science.1178296

CO 2 and Miocene Climate Change Atmospheric carbon dioxide is a powerful greenhouse gas believed to be one of the most important determinants of climate. Ice cores provide a detailed and direct record of CO 2 concentrations over the past 800,000 years, but not earlier. Tripati et al. (p. 1394 , published online 8 October) report B/Ca measurements of planktonic foraminifera, from which they can infer atmospheric CO 2 concentrations, for the past 20 million years. The concentration of atmospheric CO 2 was similar to preindustrial values for the past 10 millions years, but between 15 and 20 million years ago, during the warm lower Miocene epoch, CO 2 was more abundant, and major climate transitions toward cooler conditions occurred when CO 2 decreased substantially.