PARIS — The possibility of controlling the Earth’s temperature has long led to various experiments by inquisitive scientists, but without great results. Now a recent study found proof for the first time ever of a natural thermostat that helps regulate the planet during extreme temperature swings.
British scientists say they’ve discovered that the preeminent mechanism that allows the Earth to recover from global cooling events is linked to the weathering of rocks. Rocks dissolve by rain and river water during the weathering process, and carbon dioxide is taken from the atmosphere to carbon-rich rocks in nearby waterways. When weathering runs its course, there’s a decrease in carbon dioxide on our planet.
The researchers examined rocks from about 445 million years ago, which matches out to the second largest extinction period in the planet’s history. Using samples from Canada and Scotland, the rocks showed that the global chemical weathering rate declined, which meant less carbon dioxide was removed and the climate was able to recover from the cool temperature.
“From looking at the relative abundance of lithium isotopes in ocean-derived rocks, we were able to confirm that chemical weathering is the driver of the Earth’s natural thermostat,” explains lead scientist, Dr. Philip Pogge von Strandmann, in a news release. “When there is a warmer climate, there is more weathering, and when it is cooler there is less weathering: this is what you would expect, given that chemical reactions go faster with increasing temperature.”
The researchers had discovered evidence in earlier studies that showed weathering played a significant part in the Earth cooling down during periods of extreme heat, but the latest study proved just the opposite — when the planet experiences major cold spells, weathering slows and the “natural thermostat” allows the world to warm back up.
“This is the process that has allowed life to survive on Earth for around 4 billion years,” says Pogge von Strandman.
This study’s findings were published in the June 2017 edition of the peer-reviewed journal Geochemical Perspectives Letters.