Climate and Climate Change

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?