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Ocean Chemistry Shift Linked to Earth's Cooling Climate

1/24/2026

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Summary

Story summary

From the University of Southampton, scientists identify a key driver in Earth's transition from a warm tropical climate to the cooler, ice-covered world.
Ocean calcium concentrations fell by more than 50% over the past 66 million years.
The drop increased ocean carbon storage and reduced atmospheric CO2, cooling the planet by 15–20°C.
The study links seawater chemistry changes to seafloor spreading, suggesting oceans can drive climate change.

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Story summary

From the University of Southampton, scientists identify a key driver in Earth's transition from a warm tropical climate to the cooler, ice-covered world.
Ocean calcium concentrations fell by more than 50% over the past 66 million years.
The drop increased ocean carbon storage and reduced atmospheric CO2, cooling the planet by 15–20°C.
The study links seawater chemistry changes to seafloor spreading, suggesting oceans can drive climate change.