Question

What would most likely happen to life on Earth if the carbon cycle stopped?

Answer 1

Life would cease to exist.

Step-by-step explanation:

Answer 2

Basically everything would die off. All plants take in CO2 from the atmosphere, which is then used in photosynthesis creating glucose and oxygen. Oxygen is a definite need for us and then of course the plants are eaten and the glucose/carbon cycles through the food chain.
Since there isn't an unlimited amount of carbon available to us, we need the carbon cycle to replenish the stores.