An international expedition has tested whether an intense global warming episode 56 million years ago was caused by unusual volcanic activity in the North Atlantic has been launched by the University of Birmingham. Findings from the research are now being analysed.
If the theory is correct, it could offer scientists a step-change improvement in understanding how Earth responds to huge and rapid carbon emissions, and guide our approaches to the climate change challenges we currently face.
In May 2021 the team set sail from Galway, Ireland for the month-long PoRo-Clim expedition, which measured Earth's crust along four transects in a remote area of the Atlantic Ocean between Ireland and the southern tip of Greenland.
They aim to test a theory developed at the University, which suggested that greenhouse gas emissions released by volcanic activity could be capable of creating massive global warming events. This process, they argue, could have been responsible for the Paleocene-Eocene Thermal Maximum (PETM) – the largest temporary global warming event of the past 65 million years.
Dr Steve Jones, of the School of Geography, Earth and Environmental Sciences, headed up the expedition. “The PETM is the closest natural analogue to the climate change we are currently experiencing,” he said. “If we can start to understand how the PETM happened, and how the Earth managed to get back to normal temperatures following that event, we could learn some really valuable lessons to guide our approach now.”
Using geophysical imaging techniques, the team measured part of the Earth's crust that was forming during the PETM climate change event. They are investigating the crustal signature of an unusually hot pulse deep within the Earth's mantle interior, hypothesised to have caused a rapid outburst of magma at the time of the PETM, to provide the first physical evidence to corroborate their theory.
Matthew Allison, a PhD student at the University of Birmingham, is a co-researcher on the expedition. He said: “By the end of this expedition, we should know for sure whether the basic mechanism we proposed is correct and also how big a part it might have played in the PETM climate change event.”
The expedition was been organised in collaboration with scientists from the Dublin Institute for Advanced Science, and the Geological Survey of Denmark and Greenland, with support from the Irish Marine Institute and the EU Eurofleets+ programme.