An Interactive Introduction to Organismal and Molecular Biology, 2021

66 | SYSTEMS THINKING AND THE CARBON CYCLE
Using the definitions of each carbon flux above, develop a carbon cycle model. In the model below,
each corner is one of the spheres (e.g., atmosphere), and each arrow represents a flux, which is the
movement of carbon from one sphere to another sphere. Notice that one of the arrows (between the
atmosphere and hydrosphere) is a double arrow; one of the fluxes represents carbon moving back
and forth between the atmosphere and hydrosphere.
To complete the model below, drag each carbon flux (on the right side of the activity) to its
appropriate arrow. The two red, dotted-line arrows are human activities, and the black solid-line
arrows are natural processes.
Alternatively, feel free to complete the activity below the carbon cycle model, which addresses the
same information, but in sentence form.
An interactive or media element has been excluded from this version of the text. You can view it
online here:
https://openbooks.lib.msu.edu/isb202/?p=153
This activity meets the same objectives as above, but just in a different format. Feel free to do this
one instead or do it before creating the visual model above.
An interactive or media element has been excluded from this version of the text. You can view it
online here:
https://openbooks.lib.msu.edu/isb202/?p=153
Potential Carbon Molecule Paths
As seen in the above activity, there are many ways in which carbon moves through the earth’s spheres. To
combine the ideas of the first carbon diagram shown earlier and the created carbon model, consider what are the
more specific reservoirs of carbon in each sphere. For instance, the first model shows trees and cows, which are
in the biosphere, and fossil fuels used by factories and cars, in which fossil fuels are part of the lithosphere.