How to Make a Seashell - Just Add Water

The video explains how sea creatures like cocolithophores and snails build shells using calcium carbonate. Near the ocean surface, water is saturated with calcium and carbonate, making shell formation easy. However, at greater depths, shells dissolve more readily due to lower saturation. This creates a feedback loop where dissolved shells add calcium carbonate back to the water. Atmospheric CO2 affects ocean chemistry by reducing carbonate availability, complicating shell building. If CO2 levels rise too quickly, the ocean's balancing act may fail, leading to widespread shell dissolution and impacting marine life.

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