Required Reading P 59-61

Required reading 26

1.The matter moves through systems in numerous cycles from one part of an ecosystem to another. From one organism to another and from living organisms to the abiotic environment and back again.

2.Biogeochemical cycles involve biological, geologic, and chemical interactions.

3.Carbon exists in the form of carbon dioxide in the air, and in the ocean as the forms of carbonate and bicarbonate, and dissolved organic compounds from decay processes. It is also present in limestone as as calcium carbonate.

4.Photosynthesis removes carbon dioxide from the air and carbon dioxide and respiration put it back in.

5.Fossil fuels are coal, oil, and natural gas and the carbon from these compounds returns to the atmosphere by combustion.

6.In the carbon-silicate cycle, atmospheric C02 dissolves in rainwater to form carbonic acid. Then rainwater moves through the soil and the carbonic acid splits into hydrogen and bicarbonate ions. Next, hydrogen ions release calcium ions in chemical processes and the calcium and bicarbonate wash into surface waters and to the ocean. Then marine organisms incorporate calcium in their shells, and when they die sediments forming calcium carbonate cover their shells. Then the deposits of calcium form limestone and during geological uplift, limestone is exposed and returns the carbon dioxide back to the atmosphere.

7.Since 1750 the industrial society has used a lot of energy, most of which have obtained by burning increasing amounts of fossil fuels coal oil and natural gas. This trend along with a greater combustion of wood as a fuel and the burning of large sections of tropical forests has shifted large amounts of carbon from underground deposits to the atmosphere. In the 1700s CO2 made up .029% of the atmosphere and now it makes up .038%.