Study finds volcanoes are the planet’s thermostat

They scare, they tremble, they make people tremble and they also pollute. However, scientists at the University of Southampton, UK, have found that in addition to causing so many problems, Volcanoes play an essential role in regulating climate change: they are the Earth’s thermostat, they stabilize the temperature on the planet’s surface.

Together with fellow compatriots from the University of Leeds and other Australian colleagues from the University of Sydney and the Australian National University (ANU), as well as Canadians from the University of Ottawa, the British de Southamptron studied the combined impact of the processes on the Earth’s environment. soil, oceans and atmosphere over the past 400 million years in the Paleozoic. And they found out that vast volcanic chains were responsible for both the emission and removal of carbon dioxide (CO2) from the atmosphere.

The findings of these seven scientists have been published in the journal Geosciences of nature and oppose the previous vision: “These are the volcanic arches in geological time, which stabilized the temperatures on the Earth’s surface, and it was not thanks to a delicate balance between the seabed and the interior of the continent ”, clarify it abstract of the publication.

Volcanoes as a thermostat

The natural dissolution of rocks on the Earth’s surface is called erosion chemistry. This decomposition process causes calcium and magnesium from rocks to reach rivers, which eventually carry them to the oceans. Once in salt water, they form minerals “soft drink“which trap carbon dioxide. This feedback mechanism regulates atmospheric carbon dioxide levels, and in turn the global climate, over geological time.

“In this sense, the erosion of the Earth’s surface works like a geological thermostat “, says lead author Dr Tom Gernon, professor of earth sciences at the University of Southampton and fellow of the Turing Institute.

Martin Palmer, professor of geochemistry at the University of Southampton and co-author of the study, stipulate that volcanoes maintain the balance of nature. “On the one hand, these volcanoes pumped out large amounts of carbon dioxide which increased atmospheric levels of carbon dioxide. On the other hand, these same volcanoes helped remove this carbon through rapid weathering reactions.”

“Many processes on Earth are interdependent and there are significant time lags between the processes and their effects”, explains Eelco Rohling, professor of ocean and climate change at ANU and co-author of the study.

To partially untangle the complexity of these processes, the researchers have constructed a novel “terrestrial network“, integrating tectonic plate reconstruction algorithms. This allowed them to identify the dominant interactions in the Earth system and their evolution over time.

This is how they discovered that continental volcanic arcs have been the most important factor in the intensity of weathering over the past 400 million years. They were particularly interested in the Andes in South America and the Cascades in the United States, which are home to some of the tallest and most eroded volcanoes on the planet. Because volcanic rocks are fragmented and chemically reactive, they erode quickly and reach the oceans.

“The idea of a geological standoff between land masses and the seabed as the dominant driver of alteration of the Earth’s surface is not supported by the data “, says Dr Gernon a Europe Press.

More volcanoes for a fresher planet

Unfortunately, Ihe results do not mean that nature saves us from climate change – adds Gernon -. Today, atmospheric levels of carbon dioxide are higher than at any time in the past 3 million years, and human-made emissions are approximately 150 times greater than volcanic emissions from carbon dioxide. The continental arcs that seem to have saved the planet in the distant past are not present at the necessary scale to help counter current emissions of carbon dioxide“.

However, the observation of the university team offers an alternative to fight against climate change: artificial weathering of limestone rocks . If their spraying could be speeded up to spread them over the soil, it would also speed up the chemical reaction which would result in more calcium, potassium and sodium, which could play a key role in the safe removal of the soil. carbon dioxide of atmosphere.

“This is not a silver bullet to the climate crisis at all: we urgently need to reduce CO2 emissions in line with the IPCC mitigation pathways, period,” Gernon says, just in case. As a spokesperson for the team, he argues his discovery may help design aging plans on a large scale, an additional contribution to counter global climate change.

mm / ds