1. Biogeochemical Cycles

2. Water Cycle

3. Major Processes Heat Drives Evaporation Water Falls as Precipitation
Surface Runoff Carries Water
Runoff Causes Erosion
Water is Stored in Aquifers and Glaciers
Microorganisms Purify Water

4. Human Effects on Water Cycle
Deplete Aquifers and Use Freshwater
Increase Runoff by Clearing Vegetation and Destroying Wetlands
Add Nutrients
Warming Increases Evaporation

5. Runoff

6. Carbon Cycle

7. Major Processes Producers Remove CO2
Carbon is Stored in Plant Material and Fossil Fuels
Oceans Absorb CO2 (Carbonic Acid)
Shelled Organisms Form Calcium Carbonate (CaCO3)
Combustion, Respiration and the Warming of the Oceans Release CO2

8. Human Effects on the Carbon Cycle
Clearing of Trees and Vegetation Reduces the Rate of CO2 Uptake
Burning of Fossil Fuels and Wood Releases CO2

10. Nitrogen Cycle

11. Major Processes
Nitrogen Fixing Bacteria Convert Nitrogen Gas (N2) to Ammonia (NH3)
Nitrification by Bacteria Converts NH3 to Nitrite (NO2-) and Nitrate (NO3-)
Plants Take up NH3 and NO3
Consumers Move Nitrogen (Amino Acids) through Food Webs
Ammonification Converts Nitrogen Rich Waste into NH3
Denitrifying Bacteria Convert NO3 to N2

12. Human Effects on the Nitrogen Cycle
Nitric Oxide (NO) is Released through Combustion
Nitrous Oxide (N2O) is Released by Bacteria Living on Livestock Waste
NO3 Leaches into Groundwater
Nitrogen from Runoff Disrupts Aquatic Ecosystems
Nitrogen is Depleted from the Topsoil
Beneficial Bacteria are Harmed by Farming

13. Natural Nitrogen Fixation

14. Haber-Bosch Process

15. Phosphorus Cycle

16. Major Processes Part of DNA and ATP
Phosphate Salts (PO43-) Stored in Rock an Ocean Sediments
Geological Processes Expose Seafloor
Erosion Washes PO4 into Water
Some is Absorbed by Plants
Some Washes into the Ocean

17. Human Effects of Phosphorus Cycle
Phosphate is Mined to Make Fertilizer
Runoff Increases the Amount of Phosphate in Streams, Lakes, Rivers and the Ocean
Phosphates are Used in Detergents and Discharges from Sewage Contain High Levels of Phosphorus

18. Phosphate Mine

19. Algal Bloom

20. Sulfur Cycle

21. Major Processes
Sulfur is Found in Minerals and Rocks in the Form of Sulfate (SO42-)
Volcanic Emissions Include Hydrogen Sulfide (H2S) and Sulfur Dioxide (SO2)
Sulfate Salts from Sea Spray and Fires Enters the Atmosphere
Plants Absorb Sulfate through Roots
Marine Algae Produce Dimethyl Sulfide or DMS (CH3SCH3), a Nuclei for Condensation
DMS is Converted to SO2 which is Converted to Sulfuric Acid (H2SO4)

22. Human Effects on Sulfur Cycle
Burning Coal Releases Sulfur
Sulfur is Separated during the Refining of Gas and Heating Oil
Processing Metallic Ores Releases SO2
SO2 is a Major Contributor to Acid Deposition

23. Acid Rain