The Carbon Cycle: Earth's Breathing System
Understanding how carbon flows through our planet and why it matters for climate change
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Section 1 of 5What is the Carbon Cycle?
The carbon cycle is Earth's fundamental breathing system - the continuous movement of carbon atoms through the atmosphere, biosphere, hydrosphere, and geosphere. Carbon exists in various forms: as carbon dioxide (CO₂) gas in the air, dissolved in oceans, stored in biomass, or locked away in rocks and fossil fuels.
For billions of years, this cycle maintained a delicate balance. Natural processes like photosynthesis, respiration, volcanic activity, and weathering kept atmospheric CO₂ levels relatively stable. But human activities have disrupted this balance, adding unprecedented amounts of carbon to the atmosphere and altering the entire system.
Why Carbon Matters for Climate
Carbon dioxide is the most important greenhouse gas, trapping heat in our atmosphere. Understanding the carbon cycle is crucial because it explains both natural climate regulation and how human activities are causing rapid climate change.
Interactive Carbon Cycle Overview
Atmosphere
750 Gt C
Biosphere
600 Gt C
Oceans
38,000 Gt C
Geosphere
75,000,000 Gt C
Key Carbon Flows
Human Impact
Human activities add ~10 Gt C/year to the atmosphere, disrupting this natural balance and causing climate change.