How are humans changing the carbon cycle?
Humans are planting more trees to add more oxygen to to the carbon cycle.
Humans are adding carbon to the Earth by over-farming,
Humans are burning carbon and putting it into the atmosphere.
Answer: Humans are burning carbon and putting it in the atmosphere
Explanation: Plants breathe carbon dioxide. But we are often cutting them down and the carbon dioxide stays in the air. We can do nothing about it unless we stop cutting down plants, and this can sometimes cause global warming.
