When we breathe we breathe in oxygen , our bodies take that in and flush it throughout our system, this causes it to be used and now it comes out as carbon.
Answer : Trees take in that carbon the same way we take in oxygen.When a tree let's out it's used carbon , it comes out as oxygen for us to use. This is called Photosynthesis .
Photosynthesis forms when Carbon dioxide mixes with Water in the Atmosphere this forms glucose.
This cycle will repeat none stop, I really hope this helps you a lot :)
