Scientists at the University of Southampton found that extensive chains of volcanoes are responsible for emitting and removing atmospheric carbon dioxide (CO2). This feature allowed them to conclude that they were the main factors in stabilizing the temperature on the Earth’s surface, in the last 400 million years.
Researchers from the University of Sydney, the Australian National University (ANU), the University of Ottawa and the University of Leeds sought to discuss the hypothesis that the Earth’s climate stability over hundreds of millions of years is due to a balance between the seabed and continental interiors.
“The idea of a tug of war between the landmasses and the seabed is not supported by the data.”said the study’s lead author, Tom Gernon, associate professor of Earth Sciences at the University of Southampton and a fellow at the Turing Institute.
Volcanoes, regulators of the Earth’s temperature
The natural decomposition and dissolution of rocks in the surface of the earth is called chemical weathering. This mechanism is crucial because the products of weathering (elements such as calcium and magnesium) travel through rivers to the oceans, where they form minerals that they retain CO2.
The feedback procedure regulates atmospheric CO2 levels it’s your turn, the global climate, over geological time.
“In this sense, the wear of the earth’s surface works like a thermostat”said Gernon. “Many processes on Earth are interconnected and there are some significant delays between processes and their effects,” explained Eelco Rohling, co-author of the study.
Algorithms and tectonic plates
To handle the complex study, the team built a new “terrestrial network”, incorporating machine learning algorithms and tectonic plate reconstructions. This allowed them to capture the dominant interactions within the Earth system and see how they evolved over time.
Thus, they discovered that volcanic arcs were important in weathering for the last 400 million years.
Martin Palmer, professor of geochemistry at the University of Southampton and co-author of the study, said: “It’s a balancing act. On the one hand, these volcanoes pumped large amounts of CO2 that increased atmospheric CO2 levels. On the other hand, these same volcanoes helped to remove this carbon through rapid weathering reactions. “
Today, continental arcs are formed by chains of volcanoes, for example, in the Andes in South America and in Cascades in the United States.
A solution to climate change?
Atmospheric CO2 levels are higher than at any other time in the last 3 million years, and anthropogenic emissions are some 150 times bigger than volcanic CO2 emissions, the researchers explain.
“Unfortunately, the results do not mean that nature alone will save us from climate change”, Gernon emphasizes.
“Although volcanic arcs seem to have saved the planet in the past, they are not on the scale needed to help contain current CO2 emissions,” explained Gernon.
Although, The team’s findings provide crucial information on how society can manage the climate crisis. Artificially enhanced rock weathering, where rocks are pulverized and scattered across the earth to speed up chemical reaction rates, could play a key role in safely removing CO2 from the atmosphere.
Such schemes can be optimally implemented using calc-alkaline volcanic materials (those containing calcium, potassium and sodium), such as those found in continental arc environments.