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Carbon Cycle

The carbon cycle is how carbon in all of its various forms moves between plants, animals, the oceans, and the atmosphere. The graphic shows how carbon moves. When it’s in the atmosphere, carbon is combined with two oxygen atoms making a molecule called carbon dioxide (CO₂). Plants absorb carbon dioxide and sunlight to make their own food. This process is called photosynthesis. In this process, carbon becomes part of the plant, and the plant releases oxygen. When the plants die and are buried under layers of earth for millions of years, they may become fossil fuels like coal, oil and natural gas.

When these fuels are burned, the carbon is released back to the atmosphere. Some of it is as carbon monoxide (where carbon is combined with only one oxygen atom), and this is a poisonous gas. The rest combines with two oxygen atoms to again form CO₂. Animals do just the opposite as plants. They inhale air from the atmosphere, use the oxygen, and exhale CO₂.

As the world has industrialized over the past 150 years, man is causing much more carbon to be released into the atmosphere. This additional carbon in the atmosphere is what some scientists believe is a part of causing our earth to warm up. This is why you hear people concerned about global warming. And it is why many people are looking for ways we can reduce the amount of carbon we produce, and for ways to remove carbon that is already there.