reveiw for test wednesday

     We have a test on Wednesday on environmental geography. Some notes from our review; for hundreds of centuries the earth has cycled between ice ages and thaws. It has always been part of the natural order of things. Our impact has included raising the planets temperature by 1.2 F to 1.4 F in the last hundred years. Compare this to your basic pattern of glacial periods, usually last between 40,000 to 100,000 years. Burning fossil fuels, produces carbon dioxide. Carbon dioxide intensifies the greenhouse effect, which causes heat to be reflected back to earth. Carbon dioxide and methane have reached their highest levels in 420,000,000 years. Sources: cars, factories, power plants, trucks, jets. Rising sea levels which could flood coastal areas. Severe drought (warm areas) and species unable to adapt to the changing conditions, the animals can face extinction. 10 of the last 13 years were the warmest on record. Corals and species at risk, oysters and clams are calcified. The food web (food chain in ocean) are endangered.