Enviropedia
Climate Change
Global Warming
Ozone
Air Pollution
Weather & Climate
Sustainability
Kids
INFORMATION
Climate System
Climate Change
Empirical Study
Climate Models
Palaeoclimates
Global Warming
Introduction
Greenhouse Effect
Enhanced G-Effect
Greenhouse Gases
 - Carbon Dioxide
   - Sources
   - Sinks
   - Carbon Cycle
   - Concentrations
   - Equilibrium
 - Methane
   - Sources
   - Sinks
   - Concentrations
 - Nitrous Oxide
   - Sources
   - Sinks
   - Concentrations
 - Halocarbons
   - Sources
   - Sinks
   - Concentrations
 - Ozone
 - Other Trace Gases
 - Adjustment Time
 - Summary
Greenhouse Forcing
 - Forcing Factors
 - GWPs
 - ΔF-ΔC Relationships
 - 1765 to 1990
 - Ozone
Aerosols
 - Aerosols
 - Radiative Forcing
   - Direct
   - Indirect
 - Total Forcing
Climate Variations
 - Surface Temperature
 - Precipitation
 - Other Variations
   - Stratosphere
   - Cryosphere
   - Circulation
   - Cloudiness
Detection
 - Modelling
 - Attribution
   - Latitudes
   - Stratosphere
   - Precipitation
   - Sea Level Rise
   - Fingerprints
 - When?
Future Climate
 - GCM Simulations
 - Feedbacks
   - Water Vapour
   - Clouds
   - Ice Albedo
   - Greenhouse Gases
 - 21st Century
Impacts
 - Agriculture
 - Forestry
 - Ecosystems
 - Water Resources
 - Oceans & Coasts
 - Humans & Health
Responses
 - Stabilising
 - FCCC
 - Kyoto Protocol
 - UK Programme
   - Energy Demand
   - Energy Supply
 - Evaluation
Conclusion
LINKS
Navigate

6.4.1. Carbon Dioxide and the Carbon Cycle

Carbon in the form of CO2, carbonates and organic compounds is cycled between the main reservoirs of its biogeochemical system: the atmosphere, ocean, land and marine biota, and over geologic time scales, the sediments and rocks (Butcher et al., 1992). This is schematised in Figure 6.1.

The global carbon cycle, like other biogeochemical cycles, exists in dynamic equilibrium. Today, the atmosphere stores approximately 750 billion tonnes (Gt) of carbon (in the form of CO2). The deep ocean represents an enormous store of carbon, with over 38,000Gt, whilst the surface ocean contains roughly 1,000Gt (Schimel et al., 1995).