1.  Factors affecting temperature
    A.  4 factors
        1.  latitude
        2.  altitude
        3.  distance from large bodies of water
        4.  ocean currents
2.  Latitude
    A.  Close to equator = warm
    B.  Farther away from equator = colder
    C.  3 zones
        1.  tropical zone
        2.  polar zone
        3.  temperate zone
3.  Altitude
    A.  More important than latitude
    B.  fig. 2, pg. 540
4.  Distance from large bodies of water
    A.  Closer to water = cooler
    B.  Farther away=warmer
5.  Ocean Currents (fig. 3, pg. 541)
    A.  Warm currents bring warm air to land
    B.  cold currents bring cold air to land

Summary

Left side
Drawing of a Rainshadow

1. Principle-
    A.  If plants or animals today need certain conditions to live, then similar plants and animals in the past also require those conditions.
2.  Ice ages
    A.  Huge sheets of ice called glaciers convered large parts of Earth's surface
    B.  At least 4 ice ages
        1.  one lasted 100,000 years
        2.  last one ended 10,500 years ago
3.  Causes of Cimate change
    A.  Possible explanations
        1.  variations in the position of Earth relative to the sun
        2.  changes in the sun's energy output
        3.  movement of conditions

Summary

Left side
Bering Land Bridge wksht.

1.  Greenhouse Effect
    A.  fig. 19, pg. 566
        describe
    B.  Human activities that add greenhouse gases to the atmosphere may be warming Earth's atmopshere
2.  Ozone
    A.  Chemicals produced by humans have been damaging the ozone layer
    B.  Main cause
        1.  chlorofluorocarbons
        2.  from aersols, spray cans, freon
    C.  Ozone blocks ultrviolet radiation
        1.  a decrease in ozone means an increase in amount of ultraviolet radiation that reaches Earth's surface
    D.  More ultraviolet radiations are harmful to living things

summary

Left side
    Using the information you learned in chapter 17 write about "How you think humans have affected the environment".