Ocean Carbon Cycle

Carbon dioxide is produced by organisms during respiration, as well as by burning fossil fuels, like coal. Having too much carbon dioxide in the atmosphere causes global warming by trapping heat in between Earth's surface and the atmosphere.

Phytoplankton use carbon dioxide and sunlight to make food, exactly like plants on land. In fact, phytoplankton capture as much carbon as land plants do every year!

Phytoplankton are a major food source for larger organisms. In turn, the waste from those larger organisms provides the nutrients that encourage phytoplankton growth.

Waste and dead organisms will decompose and sink. The carbon released in that process becomes part of the deep sea carbon sink. Other organic matter is eaten by other deep sea organisms or settles onto the sediment on the sea floor. 

In places where water is pushed away from the shore, upwelling occurs. Upwelling is where cold, carbon rich water from the deep ocean is brought to the surface. This usually leads to highly productive areas with lots of life!