What is the role of the ocean in the global carbon cycle?

The ocean plays a crucial role in the global carbon cycle, absorbing and storing large amounts of carbon dioxide (CO2) from the atmosphere. This process, known as the ocean carbon sink, helps to regulate the amount of CO2 in the atmosphere, mitigating the impact of human-induced climate change.

When CO2 is dissolved in seawater, it reacts with water molecules to form carbonic acid, which can then break down into hydrogen ions and bicarbonate ions. This process increases the acidity of the water and reduces the availability of carbonate ions, which many marine organisms use to build their shells and skeletons.

The ocean carbon sink is largely driven by the biological pump, which involves the uptake of carbon by marine organisms through photosynthesis and the subsequent transfer of carbon to the deep ocean through sinking particles and vertical mixing. The physical pump, which involves the mixing of surface waters with deeper waters, also plays a role in transporting carbon to the deep ocean.