Plants and trees absorb CO₂ and breathe out oxygen. Humans and animals breathe in oxygen and exhale CO₂. This is part of the short-term carbon cycle. The long-term carbon cycle is a process of millions of years. When plants and animals die, some of their organic remains are stored in the soil. This is how coal, oil and natural gas are formed in a long-term process. These natural carbon cycles provide a natural balance between the emission and storage of CO₂.
From the moment mankind started burning fossil fuels, there is more CO₂ in the atmosphere than is stored. We have broken the natural cycle and it is time to restore it.