Since there has been life on Earth for billions of years, Susan Brantley, Evan Pugh University Professor and Barnes Professor of Geosciences at Penn State, said, “We know Earth’s temperature has been stable enough for there to be liquid water and to support life.” Although no one has ever truly agreed on the thermostat’s temperature sensitivity, silicate rock weathering is thought to function as one.
The scientists noted that it has been difficult to generate global estimates of how weathering responds to temperature changes from the results of laboratory research alone because there are many elements that go into weathering.
To better understand how the primary rock types on Earth weather, the researchers coupled laboratory measurements with soil analyses from 45 soil sites around the world and numerous watersheds. They then used their findings to develop an estimate of how weathering responds to temperature on a global scale.
According to Brantley, “you get different values when you do research in the laboratory vs obtaining samples from dirt or a river.” “In this study, we wanted to understand how we can make sense of all the data geochemists around the world have been accumulating about weathering on the planet by looking across those multiple spatial scales. And this study serves as an example of how to achieve that.
The balancing act of carbon dioxide in the Earth’s atmosphere is partially represented by weathering. Throughout Earth’s history, volcanoes have released a lot of carbon dioxide, but weathering instead of converting the world into a hot house slowly absorb the greenhouse gas.
Rain removes carbon dioxide from the atmosphere, generating a weak acid that falls to the surface of the Earth and erodes silicate minerals. According to experts, the leftovers are transported by streams and rivers to the ocean, where the carbon is eventually trapped in sedimentary rocks.
It has long been believed that the equilibrium between the amount of carbon dioxide that volcanoes release into the atmosphere and the amount that is removed by weathering over millions of years keeps the planet’s temperature essentially constant, according to Brantley. The crucial point is that as the earth warms and carbon dioxide levels rise, weathering accelerates and draws out more carbon dioxide. Weathering also takes longer when the globe is cooler.
However, a lot is still unknown regarding how sensitive weathering is to temperature changes, in part because to the extensive time and space scales involved.
According to Brantley, the study of crucial zones, which includes everything from the tallest flora to the deepest groundwater, has improved our understanding of the intricate relationships that affect weathering.
For instance, water needs to enter fissures in rocks for the materials to begin degrading. In order for that to occur, the rock must have significant exposed surface areas, which is less likely to occur where the soil is deeper.
Brantley claimed that you can only begin to recognise what is truly significant when you begin spanning spatial and temporal scales. Surface area is quite significant. You can measure all the rate constants you want for that solution in the lab, but you will never be able to predict the actual system until you can explain to me how surface area forms in the natural system.
“The researchers said in the journal Science that their study’s estimations of soil and river temperature sensitivity were lower than those obtained from laboratory temperature sensitivity studies. They upscaled these findings to predict the weathering’s dependence on the average world temperature using observations from the lab and field sites.
Their model may be useful for predicting how weathering will respond to future climate change and for assessing human-made initiatives to accelerate weathering in order to remove more carbon dioxide from the atmosphere, such as carbon sequestration.
One suggestion has been to speed up weathering by excavating a lot of rock, processing it, moving it, and then leaving it in the fields to deteriorate naturally, according to Brantley. “And that will work; in fact, it already is. The process is quite slow, which is the issue.
Although warming would hasten weathering, the scientists warned that it might take thousands or even millions of years to remove all the carbon dioxide that people have added to the atmosphere.
Understand how the “Earth’s Thermostat” helps regulate climate and keep things balanced! Learn more to discover the incredible power of nature.