18.14):
Figure 18.14: ( 3 )The amazing transformation that has happened here is changing energy from sunlight into
chemical energy that plants and animals can use as food (Figure18.15).
Figure18.15: Thisdiagramofthecarboncycleshowssomeoftheplacesacarbonatommight
be found. The black numbers indicate how much carbon is stored in various reservoirs, in
billions of tons (”GtC” stands for gigatons of carbon; figures are circa 2004). The purple
numbers indicate how much carbon moves between reservoirs each year. The sediments, as
defined in this diagram, do not include the ̃70 million GtC of carbonate rock and kerogen.
( 18 )
Carbon Can Also Cycle in the Long Term
As described above, an individual carbon atom could cycle very quickly if the plant takes
in carbon dioxide to make food and then is eaten by an animal, which in turn breathes out
carbon dioxide. Carbon might also be stored as chemical energy in the cells of the plant or
the animal. If this happens, the carbon will stay stored as part of the organic material that
makes up the plant or animal until it dies. Some of the time, when a plant or animal dies, it
decomposes and the carbon is released back into the environment. Other times, the organic
material of the organism is buried and transformed over millions of years into coal, oil, or