Some science requires generational amounts of time. And some science requires eons worth of time. Such is the case with scientists trying to understand an event known as the ‘Palaeocene-Eocene Thermal Maximum’ or PETM, which occurred about 56 million years ago. During this time, the planet warmed by five to eight degrees Celsius, resulting in the extinction of numerous deep-sea organisms.

Now, in a new paper to be published in Nature Geoscience, scientists analyze cores taken from around the North Atlantic and found substantial evidence that the final stages of Greenland and Europe rifting apart released massive amounts of carbon from the mantle. The evidence shows that this period of intense volcanic activity lasted over 200,000 years, which makes it a close match to the 170,000 years of the PETM. Lead author Tom Gernon explains: This finding is significant because we know that parts of the continental mantle in this region are enriched in carbonates, a major source of carbon. This rapid increase in mantle melting likely released a very large volume of carbon – certainly more than we had previously expected.

Because the PETM resulted in a distinct global warming event, scientists are using it as an analog for the current climate change, despite the difference in mechanism. They’re interested in the cause, but they are also interested in the biological outcome. A mass extinction event changes the course of evolution on Earth, and that seems to be where we are currently headed.

More Information

University of Southampton press release

“Transient mobilization of subcrustal carbon coincident with Palaeocene–Eocene Thermal Maximum,” Thomas M. Gernon et al., 2022 June 23, Nature Geoscience