The physical carbon pump is most efficient in colder sea water. This is because the colder water can absorb more CO2 and because it is denser than warmer water. The solute CO2 is pulled into the ocean depths along with the sinking surface water, and stays “sunk” until the deeper water naturally returns to the surface in the future.
The biological pump is similar to the physical carbon pump in that the CO2 sinks to the ocean depths. However, in the biological pump, the CO2 is consumed by algae and is bound in their cells when the algae die. The algae die when there is an overabundance of them in a certain area, therefore limiting the nutrient supply and therefore starving to death. This biological process only cares for a small amount of organic carbon; however, it is very significant for the fact that it keeps the carbon out of circulation for hundreds to thousands of years.