Overview
- Researchers report that dissolved calcium in seawater has fallen by more than half since the start of the Cenozoic.
- The team estimates that this shift contributed to a long-term global temperature drop of roughly 15–20°C.
- Chemical analyses of fossilized foraminifera yield a detailed record connecting ocean ion changes to atmospheric CO2 levels.
- Carbon-cycle modeling indicates calcium concentrations influence how marine organisms produce and bury calcium carbonate, altering long-term carbon storage.
- The decline in calcium coincides with a slowdown in seafloor spreading, linking tectonic processes to changes in ocean chemistry and climate.