A carbon sink is a natural or artificial reservoir that stores carbon-containing chemical compounds for a long period. Carbon sinks absorb more carbon than they release.
A forest, ocean, or other natural environments produce surplus carbon. Carbon sinks are very important in our environment. They can be natural or man-made. Soil, ocean, forest and the atmosphere all store carbon and this carbon moves in a continuous cycle. The largest carbon sinks become swamps, bogs, and eventually coal measures.