Earth’s thermostat appears to be breaking due to climate change

Rocks, rain and carbon dioxide helped control the Earth’s climate for thousands of years, just like a thermostatthrough a process called erosion. A new study that has just been published in the journal Sciencedirected by Penn State University scientistsprovides a better understanding of how this thermostat reacts to temperature changes.

“Life has been present on this planet for billions of years, so we know that the Earth’s temperature has remained constant enough that there is water to make sustainable living -explain Susan Brantley, a professor at Evan Pugh University and a geoscientist at Penn State’s Barnes Laboratory. The idea is that the weathering of silicate rocks is this thermostat, but no one really agrees on its temperature sensitivity.”

Because so many factors go into weathering, it has been difficult to use only the results of laboratory experiments to create overall estimates of how weathering responds to changes in temperature, the scientists explained in their new item. The combined team of laboratory medicines and analysis of only 45 sites of todo el mundo and muchas hidrográficas cuencas to better understand the meteorization of the main types of rocks in the Tierra and use these hallazgos to create an overall estimate of how the misma responds to temperature.

“When you do experiments in the lab instead of taking samples from soil or from a river, you get different values,” Brantley said. So what we’re trying to do in this research is look at these different spatial scales and figure out how we can make sense of all this data that geochemists around the world have accumulated about the weathering of the planet . And this study is a model of how we can do that. a natural balance

The weathering represents part of a balancing act of carbon dioxide in the Earth’s atmosphere. Volcanoes emitted large amounts of carbon dioxide throughout the planet’s history, but instead of turning it into a greenhouse, the gases are slowly being removed by time. The rain absorbs carbon dioxide from the atmosphere and creates a weak acid which falls to Earth and wears away the silicate rocks on the surface. The byproducts are transported by streams and rivers to the ocean, where the carbon is ultimately stored in sedimentary rocks.

“It has long been hypothesized that the balance between carbon dioxide entering the atmosphere through volcanoes and carbon dioxide removed by erosion over millions of years keeps the temperature of the planet relatively constant” , Brantley said. The key can be detected when there is more carbon dioxide in the atmosphere and the planet is warming, weathering is faster and extracting more carbon dioxide. And when the planet is colder, the weather slows down.”

But much remains to be known about weathering’s sensitivity to temperature changes, in part because of the long spatial and temporal scales involved. “In a soil profile, what you see is an image where the camera shutter was open, sometimes, for a million years: there are embedded processes happening during that time, and so we have tried to try and compare that with two year-long experience,” Brantley explained.

She said the field of hotspot science, which examines landscapes from the highest vegetation to the deepest groundwater, has helped scientists better understand the complex interactions that influence weathering. For example, they now know that rocks must fracture for water to enter the cracks and begin to break down materials. For this to happen, the rock must have large exposed surfaces, and this is less likely to happen in regions with deeper soil. “It’s only when you start moving across spatial and temporal scales that you start to see what’s really important,” Brantley said.

“Acreage is really valuable. You can measure all the rate constants to analyze in the lab, but until you can tell me how the surface forms in the natural system, you can never predict the real system.” The scientists reported that the measurements Laboratory temperature sensitivity were lower than estimates for soils and rivers in their study. Using laboratory and field observations, they extended their findings to estimate the dependence of global temperature on weathering. Their model may be useful for understanding how weathering will respond to future climate change and for evaluating human attempts to increase weathering to extract more carbon dioxide from the atmosphere, such as with carbon footprinting.

“One idea was to improve the weathering by digging up lots of rocks, crushing them, transporting them and putting them in fields to allow the weathering to happen,” Brantley explained. And it already works. But it is a very slow process. Although warming may accelerate weathering, removing all the carbon dioxide from the atmosphere that humans have added could take thousands or hundreds of thousands of years, the scientists concluded. Other Penn State researchers involved in the study included Andrew Shaughnessy, a doctoral student in the Department of Geosciences, and Marina Lebedeva and Victor Balashov, both senior scientists at the Earth and Environmental Systems Institute.

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