Our planet has seen big climate changes over millions of years, moving between very cold and warm states. Scientists have often pointed to shifts in atmospheric carbon dioxide as a primary cause. Recently, however, new research shows that the link between carbon and climate is much more complicated than we thought.
One key player in this complexity is Earth’s tectonic activity. Most people might think that carbon mostly comes from volcanic eruptions at tectonic plate boundaries. While that is true, it turns out that tectonic plates moving apart, like at mid-ocean ridges, also play a deciding role in shaping climate patterns.
In a recent study published in Communications, Earth and Environment, researchers discovered fascinating insights about how tectonic movements contribute to carbon cycles over the past 540 million years. The study suggests that when tectonic plates pull apart, they release carbon that has been locked in rocks. This means areas where tectonic plates diverge are just as important, if not more so, than volcanic arcs in terms of carbon dioxide release.
The oceans serve as massive reservoirs for carbon dioxide, storing it in carbon-rich rocks on the seafloor. Over time, waves of tectonic activity transport these rocks to subduction zones, where they release carbon back into the atmosphere. This ongoing cycle is known as the “deep carbon cycle.”
The research shows that throughout Earth’s history, greenhouse periods—when the planet is warmer—were times when more carbon was released into the atmosphere than could be absorbed by sediments. In contrast, during ice ages, the oceans pulled more carbon dioxide from the air, helping to cool the Earth.
A critical point in the study was the role of deep-sea sediments. These sediments are vital for regulating atmospheric carbon levels. As tectonic plates shift, they carry these carbon-rich sediments deep into the Earth, affecting the balance of greenhouse and icehouse climates.
Historically, volcanic arcs were thought to be leading contributors to increasing atmospheric carbon dioxide. But this study highlights that this view only became prominent in the last 120 million years due to tiny marine organisms called planktic calcifiers. These organisms helped sequester carbon into the seafloor sediment, shifting the sources of atmospheric carbon emissions.
Today, understanding how these tectonic processes work will aid in creating more accurate climate models. Given rising carbon dioxide levels, this knowledge is vital in anticipating future climate scenarios and addressing the impacts of human activity on our planet’s climate.
In conclusion, the delicate dance of our tectonic plates has a lasting impact on Earth’s climate. By recognizing this complexity, we can better prepare for the future and understand how to protect our planet. For more insights on climate change, visit The Conversation.
