New research argues that tectonic plate motions at mid-ocean ridges and continental rifts can drive large swings in Earth’s atmospheric carbon dioxide over deep time, shaping icehouse and greenhouse climate states across the last ~540 million years. The studies emphasize carbon released along divergent plate boundaries as a sustained, planet-scale “background” flux, rather than attributing most long-term climate shifts primarily to volcanoes. If confirmed, the idea offers a more unified way to connect seafloor spreading, the long carbon cycle, and climate history—helpful for improving how scientists interpret Earth’s past climate changes.

Highlights:

• Divergent boundaries: The work highlights mid-ocean ridges and continental rifts as key places where carbon can enter the ocean-atmosphere system through tectonic processes, potentially pacing long-term CO₂ changes even when obvious volcanic activity is not the main factor.
• Beyond eruptions: By focusing on steady emissions tied to plate separation, the researchers argue that the climate influence of the solid Earth may be dominated by persistent tectonic degassing rather than sporadic, high-profile eruptions.
• Climate framework: The proposed mechanism is presented as a way to explain alternations between icehouse and greenhouse intervals by linking changes in plate-boundary activity to shifts in carbon inputs on geologic timescales.
• Interpretation shift: The articles frame the results as a challenge to the common narrative that volcanoes are the primary long-term driver of atmospheric carbon swings, instead elevating plate-tectonic setting as the central control.

Perspectives:

• Study authors (as summarized by Sci.News): The research interpretation is that plate-tectonic processes at mid-ocean ridges and continental rifts, rather than volcanic eruptions, drove major atmospheric carbon swings over hundreds of millions of years. (Sci.News)
• ScienceAlert coverage: The ScienceAlert write-up emphasizes that a deep-crust carbon cycle linked to how Earth’s surface moves may affect climate more than previously appreciated, and that the story is not just about volcanoes. (ScienceAlert)

Sources:

• A Cycle Deep Within Earth's Crust May Affect Climate More Than We Thought - sciencealert.com
• Tectonic Plate Movements, Not Volcanoes, Drove Major Climate Shifts Over 540 Million Years - sci.news
• A Cycle Deep Within Earth's Crust May Affect Climate More Than We Thought - ScienceAlert - google.com