MORE . . . The global carbon cycle Land-use change emissions reflect the net releases of carbon that can be attributed to purposeful human action. This includes both the release of carbon from deforestation and absorption through afforestation of agricultural land.
Terrestrial sinks refer to carbon absorption outside of intentional human action.
The global carbon cycle is made up of carbon flows and stocks. Hundreds of billions of tons of carbon as CO 2 is absorbed from or emitted to the atmosphere annually through natural processes. These flows include plant photosynthesis, respiration, and decay as well as the oceanic absorption and release of CO 2 . These annual carbon flows, although large, are dwarfed by the various carbon stocks. The atmosphere, for example, contains about 750 billion tons of carbon.