One of the most rapid periods of warming in Earth’s history, the Palaeocene/Eocene Thermal Maximum (PETM), occurred as Greenland pulled away from Europe. However, details of the quantities of carbon dioxide behind the warming and where it came from had remained unclear. However, carbon dioxide from the different sources would have a very different impact on carbon isotope ratios. What’s more, while volcanic eruptions gradually release carbon dioxide over time, gases from methane deposits or sediments are released rapidly. But, says Gutjahr, the study does not rule out the possibility of some very short, sudden releases of methane and other carbon sources.

Source: The Guardian August 30, 2017 18:33 UTC