What is Deforestation? Deforestation is a problem that does not naturally occur, but most people think that it does. When people cut down trees(deforestation), they are adding more CO2 to the air, which is horrible for the atmosphere, and all the organisms on Earth. Over a very short amount of time, the amount of CO2 in the air has increased because of humans. Humans take in oxygen and throw out CO2. Plants take in CO2 and throw out oxygen. That is what allows us to breathe. If we cut down trees and kill plants, we won't be able to survive! That is why we need to stop deforestation! You can donate to some of these organizations to help stop deforestation. National Geographic World Wildlife Fund