A reconstruction of an extreme warm period shows the sensitivity of the climate system to changes in carbon dioxide (CO2) levels as well as the strong influence of ocean temperatures, heat transport from equatorial regions, and greenhouse gases on Earth's temperature.
The researchers say the new data allow for more accurate predictions of future climate and improved understanding of today's warming because past warm periods provide insight into climate change and are natural laboratories for understanding the global climate system.
Scientists from the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) group, led by the U.S. Geological Survey, examined fossils from 3.3 to 3.0 million years ago, known as the mid-Pliocene warm period.