They reveal what caused one of the most drastic climate changes in Earth history

London. A team of international scientists has come up with the cause behind one of the fastest and most drastic cases of climate change in Earth’s history, which occurred 55 million years ago.

The study, published Tuesday in the journal Nature Communications, indicates that high levels of mercury triggered the Paleocene-Eocene thermal maximum (PETM), an extreme global warming that lasted until around 150,000 years and which led to significant increases in temperature.

The researchers found that the amounts of mercury, detected in well-preserved samples of North Sea sedimentary nuclei, decreased during the early stages of abrupt climate change, suggesting that some other carbon deposit emitted significant greenhouse gases as the phenomenon progressed.

These gases were released by large volcanic eruptions, also responsible for the dispersion of mercury, so scientists set out to measure mercury and carbon in sediment nuclei to detect any ancient volcanism.

“The surprise was that we did not find a simple relationship of increased volcanism during the release of greenhouse gases,” said in a statement the co-author of the study Sev Kender, of the University of Exeter, which points to the hypothesis that a second source of gas existed after volcanic activity.

According to scientists, the research, which has also involved experts from the British Geological Survey, Oxford University, Heriot-Watt University and the University of California at Riverside, could open up new perspectives for study on how modern climate change will affect the Earth in the coming centuries.