Stretching of the continents 56 million years ago is likely to have caused one of the most extreme episodes of global warming in Earth’s history, new research suggests.
During this time, the planet experienced an increase in temperature of 5-8°C (9-14°F), culminating in the Paleocene-Eocene Thermal Maximum (PETM), which lasted about 170,000 years.
It caused the extinction of many deep-sea organisms and reshaped the course of evolution of life on Earth.
Scientists studied the effects of global tectonic forces and volcanic eruptions during the period of environmental change almost 60 million years ago.
They believe that the extensive stretching of the continental plates in the northern hemisphere – rather like the pulling of a toffee bar that thins and eventually separates – massively reduced the pressures in the Earth’s deep interior.
This then drove intense, but short-lived melting in the mantle – a layer of sticky, molten rock just below the planet’s crust.
The team, including experts from the universities of Southampton, Edinburgh and Leeds, suggests that the resulting volcanic activity coincided with, and likely caused, a massive burst of carbon release into the atmosphere linked to PETM warming.
!['Stretching' of the continents 56 million years ago is likely to have caused one of the most extreme episodes of global warming in Earth's history, new research suggests. Pictured is a false colour satellite image of the Faroe Islands - one of the locations studied by scientists](https://i.dailymail.co.uk/1s/2022/06/23/15/59436711-10945953-image-a-13_1655994767729.jpg)
‘Stretching’ of the continents 56 million years ago is likely to have caused one of the most extreme episodes of global warming in Earth’s history, new research suggests. Pictured is a false colour satellite image of the Faroe Islands – one of the locations studied by scientists
![The team studied volcanic ash layers and lavas in the laboratories of the Integrated Ocean Drilling Program’s (IODP) Bremen Core Repository, Germany](https://i.dailymail.co.uk/1s/2022/06/23/15/59436709-10945953-image-a-16_1655994777660.jpg)
The team studied volcanic ash layers and lavas in the laboratories of the Integrated Ocean Drilling Program’s (IODP) Bremen Core Repository, Germany
![Scientists found that intense episodes of volcanism were likely responsible for rapid warming during the Paleocene-Eocene Thermal Maximum warming event. Pictured is a volcano in Montserrat, West Indies](https://i.dailymail.co.uk/1s/2022/06/23/15/59436705-10945953-image-a-14_1655994769650.jpg)
Scientists found that intense episodes of volcanism were likely responsible for rapid warming during the Paleocene-Eocene Thermal Maximum warming event. Pictured is a volcano in Montserrat, West Indies
Dr Tom Gernon, an associate professor of Earth science at the University of Southampton and lead author of the study, said: ‘Despite the importance and wider relevance of the PETM to global change today, the underlying cause is highly debated.
‘It’s generally agreed that a sudden and massive release of the greenhouse gas, carbon, from the Earth’s interior must have driven this event, yet the scale and pace of warming is very hard to explain by conventional volcanic processes.’
The scientists found evidence from rock drilled from the seafloor for a widespread episode volcanic activity lasting 200,000 years, which coincided with the PETM.
Using archives of rock drilled beneath the seafloor near the edge of the Atlantic Ocean, the team found evidence of an abrupt and widespread episode of volcanic activity across the North Atlantic Ocean that lasted just over 200,000 years, strikingly similar to the duration of the PETM.
This finding prompted the researchers to investigate a broader expanse of the North Atlantic region, including Greenland and the Faroe Islands.
Here, they found that kilometre-thick piles of lava that started to erupt just before the PETM show unusual compositions that point to a significant increase in the amount of melting of the uppermost solid part of Earth’s mantle beneath the continent.
Dr Gernon said this would have led to a rapid increase of carbon being released, which would have led to the global warming.
![Fragments of lava from the Atlantic are pictured here under a microscope](https://i.dailymail.co.uk/1s/2022/06/23/15/59436701-10945953-image-a-15_1655994774170.jpg)
Fragments of lava from the Atlantic are pictured here under a microscope
![The volcanism occurred as the North Atlantic region was in the final stages of rifting, or breaking apart, in some ways similar to the geological processes occurring today in the East African Rift Valley, pictured](https://i.dailymail.co.uk/1s/2022/06/23/15/59436703-10945953-image-a-18_1655994785161.jpg)
The volcanism occurred as the North Atlantic region was in the final stages of rifting, or breaking apart, in some ways similar to the geological processes occurring today in the East African Rift Valley, pictured
The intense volcanic activity occurred just as the continental landmass that united Greenland and Europe was most intensely stretched by plate tectonic forces.
Eventually, North America and Greenland finally separated from Europe, leading to the birth of the North Atlantic Ocean.
Scientists believe it was this final phase of stretching that brought about substantial melting in the Earth’s mantle, leading to massive carbon release, and in-turn, global warming.
Dr Thea Hincks, senior research fellow at the University of Southampton and co-author on the study, said: ‘Using physically realistic estimates of the key characteristics of these volcanic systems, we show that the amount of carbon needed to drive warming could have been attained by enhanced melting.’
Dr Gernon added: ‘Such rapid events cause a fundamental reorganisation of Earth’s surface environment, altering vast ecosystems.’
The study has been published in the journal Nature Geoscience.