The Carbon Cycle: How Carbon Moves Through Earth

Carbon moves among the atmosphere, oceans, rocks, soil, and living organisms. These transfers happen on timescales ranging from minutes to millions of years.

Life exchanges carbon quickly

Plants take carbon dioxide from air or water during photosynthesis and build organic matter. Respiration, decomposition, and fire return much of it. Oceans absorb and release carbon dioxide and also store carbon in dissolved forms and marine life.

Over longer periods, sediments become rock, weathering moves carbon, and volcanoes return some to the atmosphere. Burning fossil fuels rapidly releases carbon stored underground for geological time, while deforestation reduces living storage. The cycle continues, but changing the rate of one pathway can shift the balance and climate. A cycle does not mean every reservoir remains constant.