An Ancient Carbon Mystery.

The article focuses on the climate event, the Paleocene-Eocene Thermal Maximum (PETM) which occurred 55 million years ago. The convergence of isotopic and sedimentological data suggests that the atmospheric carbon dioxide was the main greenhouse gas driving the PETM. Biological responses to the global warming during the PETM brought changes in the ecology of marine organisms, a mass extinction of benthic foraminifera and a global expansion of subtropical dinoflagellats at the earliest onset of the event.