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Cyles and Feedback Loops I
Cycles and Feedback Loops
Some Feedback Loops
Gaia as a Feedback Loop
The Earth itself is a material cycle
Over time the earth acheives a balance which is disrupted by
random catastrophe
Exponential use of resources represents a "short-term" random catastrophe
for ecosystems as this disrupts the natural resource cycles. The system
can not recover on such a short timescale.
Radiation and heat balance in a spherical
Cow
Carbon Cycle
Active Pools:
- Atmosphere: 58,000
- Ocean Surface Layers: 43,000
- Ocean Deep Layers: 2,900,000
Organic Carbon:
- Land organisms: 38,000
- Decaying Organic Matter: 58,000
- Marine Organisms: 830
- Decaying Organic Matter Oceans: 250,000
Storage Pools:
As Carbonates:
- Carbonate sediments: 1,700,000,000
As Organic Carbon:
EXCHANGES:
- Atmosphere Ocean Surface: 7--8 years
- Ocean: Surface Depth: 1000 years
- Biological Fixation: 2100 per year (5 % of Terrestrial Organic Carbon)
- Fossil Fuel Combustion Addition: 420 per year
- Diagensis Return to Fossil Fuel Reservoir = 84 units per year
Nitrogen Cycle:
Active Pools:
As Organic Nitrogen:
- Land Organisms: 870
- Marine Organisms: 69
- Decaying Organic Matter: 120,000
As Inorganic Nitrogen
- Soils 10,000
- Ocean Sediments 7,100
Storage Pools:
In solution
- Atmosphere: 270,000,000
- Oceans: 1,400,000
As Rocks:
- crustal rocks: 1,000,000,000
EXCHANGES:
- Biological Fixation Land: 3.9 units per year
- Biological Fixation Ocean: 0.74 units per year
- Atmospheric Fixation: 0.55 units per year
- Denitrification: Land 1.6; Ocean 2.9
- Industrial Fixation 3.2 (fertilizer)
- Eutrophication: reduced oxygen in water; algae thrives,
shellfish die
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