Researchers from the University of Bristol have released a study that documents the rate of environmental change that is occurring today and claims that the pace has never been seen before in the Earth's history.
The study examines a global environmental change event that took place approximately 120 million years ago and reconstructs the changes in atmospheric carbon dioxide (pCO2) that occurred during the event. The data points to increased pCO2 levels in response to volcanic outgassing at this time - these levels remained high for around 1.5 to 2 million years until they returned to normal levels due to increases in the burial of organic matter in the oxygen-deprived ocean.
"Past records of climate change must be well characterized if we want to understand how it affected or will affect ecosystems. It has been suggested that the event we studied is a suitable analogue to what is happening today due to human activity and that a rapid increase in pCO2 caused ocean acidification and a biological crisis amongst a group of calcifying marine algae," David Naafs, lead author of the study, said in a press release.
"Our work confirms that there was a large increase in pCO2. The change, however, appears to have been far slower than that of today, taking place over hundreds of thousands of years, rather than the centuries over which human activity is increasing atmospheric carbon dioxide levels," he added. "So despite earlier claims, our research indicates that it is extremely unlikely that widespread surface ocean acidification occurred during this event."
The data points to a rapid geological event in the past that occurred thousands of times slower than today, and Naff and his team believe that his drastic difference in environmental change is not connected to surface ocean acidification.
"This is another example that the current rate of environmental change has few if any precedents in Earth history, and this has big implications for thinking about both past and future change," said Daniela Schmidt, co-author of the study.
The findings were published in the Jan. 4 issue of Nature Geoscience.
