SYDNEY, July 26 (Xinhua) -- A new study led by Australia's Curtin University has found that mass extinction events caused by supervolcanoes throughout history were the result of a sudden release of carbon dioxide (CO2), adding new weight to CO2's impact on the climate.
The study, published in the Proceedings of the National Academy of Sciences on Tuesday, analyzed historic volcanoes throughout the Earth's history and the climatic shifts that followed them.
Contributing author, Hugo Olierook from Curtin's School of Earth and Planetary Sciences, told Xinhua on Tuesday that it wasn't the size of the volcanic eruption that led to climatic shifts, but the amount of CO2 they released.
"We started looking at the size of these things and comparing it to how disastrous they were towards life and climate on Earth. The initial hypothesis was bigger equals deadlier but that certainly wasn't the case."
The team was able to estimate how much CO2 major volcanic events were released by analyzing droplets of magma from volcanic rock dredged from the ocean floor.
One of the larger eruptions from a supervolcano situated on the Kerguelen Plateau in the Indian Ocean some 540 million years ago released five times less than smaller eruptions that triggered mass extinction events.
Alarmingly, the team found that in the present day industrial activity is releasing carbon dioxide at a rate 200 times faster than these supervolcanoes.
Emissions since the industrial revolution have increased CO2 levels in the atmosphere by about 50 percent.
He said while the volcano changed the climate over thousands and thousands of years, it showed we were on an unsustainable trajectory.
However, on the positive side, he said processes such as natural absorption of CO2 into soil and plant life shows that the Earth has the ability to regulate levels if given a chance.
"If we're able to slow down our CO2, then we should hopefully see a relatively minor effect on our climate and on our life our planet." ■
