What is the carbon cycle?
The carbon cycle is the movement of carbon among the atmosphere, ocean, living things, soil and rocks on different timescales.
How it works and what the evidence shows
Core idea Plants take up atmospheric carbon through photosynthesis; respiration, decay and combustion can return it. The ocean exchanges carbon dioxide with the air, while geological stores change more slowly. Evidence and research Satellite, atmospheric and ecosystem observations track reservoirs and fluxes. Storage varies across places and times.
Uses and limitations
Why it matters The cycle matters for climate and ecosystems. Burning fossil fuels rapidly moves long-stored carbon into the atmosphere and changes the balance. Common misunderstandings A natural cycle does not make additional emissions harmless. The net balance of inputs, outputs and storage changes is what matters.