New research into the geological record provides documentation that the environment is changing more rapidly now than it ever has before at any point in the Earth’s history. A new analysis of atmospheric carbon levels over time illustrates the prevailing climate science theory that the current rate of environmental changes is the highest of all time. This study reinforces the dire situation we find ourselves in, further bolstering the argument that urgent action is needed to reduce the effects of climate change and that the current increase in global temperature is not just a natural fluctuation.
A study conducted at the University of Bristol Cabot Institute, published this week, offers new evidence of the unprecedented rate of environmental change, compared to those which occurred during natural events. Researchers reconstructed the changes in atmospheric carbon dioxide (pCO2) during a global environmental change event that occurred about 120 million years ago. This was possible thanks to new geochemical data that provides evidence that pCO2 increased in response to volcanic outgassing and remained high for around 1.5-2 million years, until enhanced organic matter buried in an oxygen-poor ocean caused a return to original levels.
“Past records of climate change must be well characterised if we want to understand how it affected or will affect ecosystems,” writes lead author Dr David Naafs. “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. Our work confirms that there was a large increase in pCO2.”
The geological record – the name for all of the layers of the Earth’s strata – is often used in research on climate change issues. “For example, determining the sensitivity of Earth’s temperature to higher CO2 levels,” according to Senior Author and Director of the University’s Cabot Institute, Professor Rich Pancost. “But testing the risks associated with the pace of modern environmental change is proving problematic, due to a lack of similar rapid changes in the geological past. Consequently, these risks, in this case to the marine ecosystems on which so many of us depend, remain associated with profound uncertainty. Decreasing CO2 emissions, as recently agreed in Paris, will be necessary to avoid these risks.”
The research was published January 4 in Nature Geosciences.