Why Are Changes in the Global Carbon Cycle Important

Why are changes in the global carbon cycle important?

A) Burning reduces available carbon for primary producers and therefore primary consumers.
B) Deforestation and suburbanization reduce an area's net primary productivity.
C) Increasing atmospheric concentrations of carbon dioxide could alter Earth's climate.
D) By using fossil fuels we are destroying a nonrenewable resource.
E) All of the above are why changes in the global carbon cycle are important.