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|November 21, 2017|
Another factor figures in global warming
RIVERSIDE – (INT) - A natural global warming event that took place 56 million years ago was triggered almost entirely by volcanic eruptions. That is the theory of an international team of researchers including one from UC Riverside.
The findings, published online in Nature, refute the more commonly favored explanation that the event, called the Palaeocene-Eocene Thermal Maximum (PETM), was caused by the release of carbon from sedimentary reservoirs such as frozen methane.
“While it has long been suggested that the PETM was caused by injection of carbon into the atmosphere and ocean, the mechanism has remained elusive until now,” UCR Professor of Earth Sciences Andy Ridgwell said. “By combining geochemical measurements and a global climate model that my group has been developing for over a decade, we have shown that this event was caused almost entirely by carbon emissions from the Earth’s interior.”
Scientists are interested in studying ancient warming events to understand how the Earth behaves when the climate system is dramatically perturbed.
During the PETM, atmospheric carbon dioxide more than doubled and global temperatures rose by 5 degrees Celsius, an increase that is comparable with the change that may occur by later next century on modern Earth.
While there was significant ecological disruption during the PETM, most species were able to avoid extinction via adaptation or migration. However, the rate of carbon addition during the onset of the PETM lasted for several thousand years, whereas current climate change is occurring on a century time-scale.
Story Date: September 14, 2017