Carbon dioxide occurs naturally in the Earth’s atmosphere. Today, we talk about carbon dioxide often, when we discuss climate change, because the amount of carbon dioxide in the atmosphere is growing. Humans produce carbon dioxide naturally as a by-product of breathing. We also increase the amount of carbon dioxide when we burn fossil fuels.
Plants rely on carbon as a vital part of photosynthesis.
The carbon dioxide in the atmosphere is taken in by plants and turned into a by-product of oxygen.
This is a part of what is known as the carbon cycle.