Atmosphere:
• Atmospheric CO2 has a greenhouse effect.
• CO2 plays a vital role in photosynthesis by terrestrial plants and phytoplankton.
• Plants are important C stores which extract water from the soil and transpire.
• Water is evaporated from oceans to atmosphere, and CO2 is exchanged between the
two stores.
Oceans:
• Acidity increases when CO2 input exceeds outputs.
• Solubility of CO2 in oceans increases with lower sea-surface temperatures (SSTs).
• Atmospheric CO2 levels influence SSTs and thermal expansion, air temperatures,
melting of ice sheets/glaciers and sea level.
Vegetation and Soil:
• Water availability influences photosynthesis rate, NPP, input of organic litter to soils
and transpiration.
• Water-storage capacity of soils increases with organic content.
• Temp and rainfall affects decomposition rate and CO2 release to atmosphere.
Cryosphere:
• Atmospheric CO2 determines intensity of the greenhouse effect and melting of ice
sheets, glaciers, sea ice and permafrost.
• Melting exposes land and sea surfaces which absorb more solar radiation and raise
temps further. Permafrost melting exposes organic material to oxidation and
decomposition. Run-off, river flow and evaporation respond to temp change.
