The oceans influence the climate by absorbing and storing carbon dioxide.
Plankton influence the exchange of gases between the atmosphere and the sea.
In any given region, the relative amounts of CO2 contained in the atmosphere and dissolved in the ocean's surface layer determine whether the ocean-water emits or absorbs gas. Phytoplankton activity occurs mostly within the first 50 metres of the surface and, although oceanographers don't fully understand why, varies widely according to the season and location. Some areas of the ocean do not receive enough light or are too cold. Rather like a pump, plankton transport gases and nutrients from the ocean surface to the deep. Instead, ocean life absorbs CO2 during photosynthesis and, while most of the gas escapes within about a year, some of it is transported down into the deep ocean via dead plants, body parts, faeces, and other sinking materials.