Self-Healing Earth: Volcanoes Regulate Carbon Emissions in Atmosphere, Global Temperatures; Possible Answer to Climate Change

While volcanoes have long been held to be an inevitable cause of disaster from the Earth's moving plates, a new study reveals how they help the Earth regulate atmospheric carbon dioxide and, in turn, stabilize global temperatures.

The new study was done by researchers from the University of Southampton, colleagues from the Australian National University, the University of Sydney, the University of Ottawa in Canada, and the University of Leeds in England.

Together, they examined different physical processes on solid Earth, oceans, and atmosphere in the past 400 million years. They discovered that long chains of volcanoes are involved in the emission and the reabsorption from the atmosphere of carbon dioxide, regulating it and the temperature in the process.

Results of their study and an explanation of the newly-discovered role of volcanoes are presented in the Nature Geoscience journal. The report titled "Global Chemical Weathering Dominated by Continental Arcs Since the Mid-Palaeozoic," was published on August 23.

Volcanoes Encouraged Chemical Weathering Processes

The researchers explained in their paper that the Earth's plate tectonic activities regulate the carbon dioxide content through processes such as volcanic outgassing and weathering of various silica.

According to National Geographic, naturally occurring rocks at the Earth's surface start to break down and dissolve in a process called chemical weathering. Byproducts of chemical weathering result in heavy metals and other elements like calcium and magnesium, being eroded and flushed through running water like rivers down to larger bodies of water, like oceans.

Once these minerals are deposited into the sea, they form minerals that capture carbon dioxide. This transfer of minerals is the feedback mechanism that helps regulate atmospheric carbon dioxide and global climate in the long run.

In a news release from Leeds University, Dr. Tom Gernon said, "In this respect, weathering of the Earth's surface serves as a geological thermostat." Gernon is the lead author of the study, Associate Professor in Earth Science at the University of Southampton, and a Fellow of the Turing Institute. The study author added that the underlying controls are difficult to determine due to a host of other contributing factors.

Eelco Rohling, a co-author of the study and a Professor in Ocean and Climate Change at ANU, noted that several of Earth's processes are interlinked and that there might be significant time in between the effects of each process are felt.

Understanding How Earth's Processes Regulate Carbon Dioxide Emissions

To better understand this complex network of processes covering the surface of the Earth, the oceans, and the atmosphere, researchers devised a so-called 'Earth network,' which was built on machine learning algorithms and reconstructions of plate tectonic models.

Their developed Earth network allowed them to pinpoint which processes are more dominant compared to the others and how they responded through time. It led to the discovery that extended networks of volcanoes, formally known as continental volcanic arcs, were among the most critical factors in chemical weathering processes.

These continental arcs are long strings of volcanoes found in the length of the Andes in South America and the Cascades in the US, for example. Because the volcanoes are continuously breaking down and causing chemical weathering at a faster rate than other environments, they play a key role in the regulation of carbon dioxide and temperatures.