what would happen if there was no carbon cycle/ the carbon cycle stopped?

All living things contain carbon. Remember the equation
for cellular respiration--oxygen + carbohydrates--->carbon dioxide + water (and
releases energy). The reverse, photosynthesis, is the way that energy is captured as
sunlight, and made available for living things. Both carbohydrates and carbon dioxide
contain
carbon.

Carbon is
also found in various other compounds in our bodies, such as proteins, lipids, and
genetic material. It helps make up our teeth and bones. When carbon cycles, it also does
so through non-living things. The amount of carbon does not change; we can't get more.
If carbon did not cycle through various forms, there would not be any available for
living things, and life would not be possible. At least, not any type we are used
to.