1. Climate and Climate Change

2. What Causes Climate? - Vocabulary
Climate – The average, year-after-year conditions of temperature, precipitation, winds, and clouds in an area.
Tropical Zone – The area near the equator,
between about 23.5° north latitude and 23.5°
south latitude.
Polar Zone – The areas near both poles, from about 66.5° to 90° north and 66.5° to 90° south latitudes.
Temperate Zone – The area between the tropical and polar zones, from about 23.5° to 66.5° north and 23.5° to 66.5° south latitudes.

3. What Causes Climate? - Vocabulary
Marine Climate – The climate of some coastal regions, with relatively warm winters and cool summers.
Continental Climate – The climate of the centers of continents, with cold winters and warm or hot summers.
Windward – The side of the mountain that faces the oncoming wind.
Leeward – The downwind side of mountains.
Microclimate – The climate characteristics of a small, specific area; it may be different from the climate of the surrounding area.

4. What Causes Climate? – Main Ideas
The climate of a region is determined by its temperature and precipitation.
The main factors that influence temperature are latitude, altitude, distance from large bodies of water, and ocean currents.
The main factors that affect precipitation are prevailing winds and the presence of mountains.
The different seasons are a result of the tilt of Earth’s axis as Earth travels around the sun.

5. What Causes Climate? – Review Questions
Name the four main factors that influence the temperature of an area.
How do prevailing winds affect the amount of precipitation an area receives?
On which side of mountains – leeward or windward – does precipitation fall?
How does the tilt of Earth’s axis cause the seasons?

6. Climate Regions - Vocabulary
Rain forest – A forest in the tropical wet climate zone that gets plenty of rain all year.
Savanna – A tropical grassland with scattered clumps of trees; found in the tropical wet-and-dry climate zones.
Desert – A region that gets less than 25 centimeters of rain a year.
Steppe – A prairie or grassland found in the semiarid climate region.
Humid subtropical – a wet and warm climate area on the edge of the tropics.

7. Climate Regions - Vocabulary
Subarctic – A climate zone that lies north of the humid continental climate zone, with short, cool summers and long bitterly cold winters.
Tundra – A polar climate region, found across northern Alaska, Canada, and Russia, with short, cool summers and bitterly cold winters.
Permafrost – Permanently frozen soil found in the tundra climate region.

8. Climate Regions – Main Ideas
Climates are classified according to temperature and precipitation.
There are five main climate regions: tropical rainy, dry, temperate marine, temperate continental, and polar. Highlands are often considered to be a sixth climate region.

9. Climate Regions – Review Questions
What two factors are used to classify climates?
Briefly describe each of the five main climate types.
Give three examples of how the climate of a region affects what plants and animals can live there.

10. Long-Term Changes in the Climate - Vocabulary
Ice Age- Cold time periods in Earth’s history, during which glaciers covered large parts of the surface.
Sunspot – Dark, cooler regions on the surface of the sun.

11. Long-Term Changes in the Climate – Main Ideas
During each ice age, huge sheets of ice covered much of Earth’s surface.
Possible explanations for major climate changes include movement of continents, variations in the position of Earth relative to the sun, and changes in the sun’s energy output.

12. Long-Term Changes in the Climate – Review Questions
What types of evidence do scientists use to study changes in climate?
How was the climate during an ice age different from the climate today?
List three factors that could be responsible for changing Earth’s climates.

13. Global Changes in the Atmosphere – Vocabulary
Greenhouse gas – Gases in the atmosphere that trap heat.
Global warming – A gradual increase in the temperature of Earth’s atmosphere.
Chlorofluorocarbons – Chlorine compounds formerly used in air conditioners, refrigerators, and spray cans; also called CFC’s.

14. Global Changes in the Atmosphere – Main Ideas
Human activities that add greenhouse gases to the atmosphere may be warming Earth’s atmosphere.
Chemicals produced by humans have been damaging the ozone layer.

15. Global Changes in the Atmosphere – Review Questions
What human actions increase the amount of carbon dioxide in Earth’s atmosphere?
How could increases in carbon dioxide in the air affect world temperatures?
What chemicals are the major cause of ozone depletion in the stratosphere?