Living on Earth is a bit like winning the lottery as its cozy atmosphere stands in stark contrast to the many uninhabitable planets that surround us. For a long time, its environmental temperature stayed pretty stable, and now new research has provided novel evidence for a system that may be responsible for helping to claw the planet’s climate back from the brink.
The bad news? It takes hundreds of thousands of years to kick in. With the Anthropocene speeding up the rate of warming to an unprecedented degree, it could be that Earth’s self-stabilizing mechanisms won’t have time to take effect.
One way in which this self-stabilizing mechanism may work is something called silicate weathering, in which carbon dioxide is sucked out of the atmosphere by chemical reactions occurring on certain rocks. The mechanism has received fresh support as a climate stabilizing mechanism by a new study that used mathematical modeling to study the Earth’s historic climate fluctuations, both on a small and large timescale.
Their models revealed a system spanning hundreds of thousands of years during which time temperature fluctuations would wax and wane but don’t grow beyond a certain point. The researchers noted that the time taken to do so was in line with the process of silicate weathering, which is thought to take around 100,000 years to kick in.
“We suggest that this is strong observational evidence for the importance of silicate weathering as a climate stabilizer,” write the authors. “Through this, it further supports the widely used steady-state assumption, existing models of the long-term effects of anthropogenic CO2 emissions, and the idea that the weathering feedback should play a key role in planetary habitability.”
While silicate weathering has long been considered a potential driver for Earth’s stability, this new research is the first of its kind in bringing hard data to the idea. The discovery is bittersweet, demonstrating that left to its own devices, the planet has a few tricks up its sleeve for returning to a habitable state. However, unless humankind slows its environmental impact, these tricks might become redundant.
“On the one hand, it's good because we know that today's global warming will eventually be canceled out through this stabilizing feedback," lead author Constantin Arnscheidt, a graduate student in MIT's Department of Earth, Atmospheric, and Planetary Sciences, told Phys.org. "But on the other hand, it will take hundreds of thousands of years to happen, so not fast enough to solve our present-day issues."
The study was published in Science Advances.