2. Chapter: Climate Table of Contents Section 3: Climatic ChangesClimatic Changes Section 1: What is climate? Section 2: Climate TypesClimate Types

3. Climate is the pattern of weather that occurs in an area over many years. It determines the types of plants or animals that can survive, and it influences how people live. Climate What is climate? 1 1 Climate is determined by averaging the weather of a region over a long period of time, such as 30 years.

4. Latitude, a measure of distance north or south of the equator, affects climate. Latitude and Climate What is climate? 1 1 The tropics—the region between latitudes 23.5°N and 23.5°S—receive the most solar radiation because the Sun shines almost directly over these areas.

5. The polar zones extend from 66.5°N and 66.5°S latitude to the poles. Solar radiation hits these zones at a low angle, spreading energy over a large area. Latitude and Climate What is climate? 1 1 Polar regions are never warm.

6. Latitude and Climate What is climate? 1 1 Between the tropics and the polar zones are the temperate zones. Temperatures here are moderate. Most of the United States is in a temperate zone. Take 3 minutes to draw this image in your notes: Label the latitudes and zones associated with those latitudes Page 589

7. It takes a lot more heat to increase the temperature of water than it takes to increase the temperature of land. Other Factors — Large Bodies of Water What is climate? 1 1 In addition, water must give up more heat than land does for it to cool.

8. Large bodies of water can affect the climate of coastal areas by absorbing or giving off heat. Other Factors — Large Bodies of Water What is climate? 1 1

9. Ocean currents affect coastal climates. Ocean Currents What is climate? 1 1 Warm currents begin near the equator and flow toward higher latitudes, warming the land regions they pass.

10. Ocean Currents What is climate? 1 1 When the currents cool off and flow back toward the equator, they cool the air and climates of nearby land. Winds blowing from the sea are often moister than those blowing from land. Therefore, some coastal areas have wetter climates than places farther inland.

11. At the same latitude, the climate is colder in the mountains than at sea level. Mountains What is climate? 1 1 When radiation from the Sun is absorbed by Earth’s surface, it heats the land.

12. Mountains What is climate? 1 1 Heat from Earth then warms the atmosphere. Because Earth’s atmosphere gets thinner at higher altitudes, the air in the mountains has fewer molecules to absorb heat.

13. On the windward side of a mountain range, air rises, cools, and drops its moisture. Rain Shadows What is climate? 1 1 On the leeward side of a mountain range air descends, heats up, and dries the land.

14. Streets, parking lots, and buildings heat up, in turn heating the air. Cities What is climate? 1 1 Air pollution traps this heat, creating what is known as the heat-island effect. Temperatures in a city can be 5°C (41 F) higher than in surrounding rural areas.

15. Section Check 1 1 Question 1 The pattern of weather that occurs in an area over many years is called that area’s __________. A. atmosphere B. climate C. hemisphere D. zone

16. 1 1 Section Check Answer The answer is B. Climate determines the types of plants or animals that can survive in an area; it also as influences how people live.

17. 1 1 Section Check Question 2 The region between latitudes 23.5º N and 23.5º S is the __________. A. arctic B. polar zone C. temperate zone D. tropics

18. 1 1 Section Check Answer The answer is D. The tropics receive the most solar radiation and have temperatures that are always hot, except at high elevations.

19. 1 1 Section Check Question 3 According to this figure, most of the United States is in __________. A. a polar zone B. a temperate zone C. the Tropic of Cancer D. the Tropic of Capricorn

20. 1 1 Section Check Answer The answer is B. Most of the United States is in a temperature zone, between the tropics and the polar zone.

21. Classifying Climates Climatologists—people who study climates— usually use a system developed in 1918 by Wladimir Köppen to classify climates. Köppen observed that the types of plants found in a region depended on the climate of the area. He classified world climates by using the annual and monthly averages of temperature and precipitation of different regions. Climate Types 2 2

22. Classifying Climates The climate classification system separates climates into six groups— tropical, mild, dry, continental, polar, and high elevation. Climate Types 2 2

23. Classifying Climates Climate Types 2 2

24. How are climate classified? All of them are classified by temperature EXCEPT…. Dry climates –Dry climates are classified by amount of precipitation that falls over an area

25. Pages 593-599 What are Humid Tropical Climates, Humid Mid- Latitude Climates and Dry Climates? Fill in the blanks: 1. World Climates –A. Humid tropical Wet tropics –B Humid mid-latitude –C Dry

26. Climates Table 1- Wet Tropical Table 2- Tropical Wet and Dry Table 3- Humid Mid – Latitude (mild winters) Table 4- Humid Mid – Latitude (severe winters) Table 5- Polar Climates Table 6- Highland Climates

27. Assignment Read about your climate and make notes of the key ideas in the text. I will call on a representative of your table to share with the class

28. Climate Wet Tropical Tropical Wet and Dry Humid Mid- Latitude with Mild Winters Humid Mid- Latitude with Severe Winters Polar Highland

29. Map Master Page 594-595 (Sahara = northern Africa) 1)Do the map master skills activity 2)Answer the following: Name 3 places that have severe winters Name 4 places that have arid climates What climate does NC have? Pick a place to go on vacation that would have a tropical wet and dry climate.

30. Worldwide Climate Zone Activity Objective: To identify the Earth’s climate zones by isotherm boundaries To analyze a map of the Earth’s climate zones

31. Section Check 2 2 Question 1 What two factors do climatologists use to classify climates?

32. Section Check 2 2 Answer Climatologists use a system developed by Wladimir Koppen that classifies climates using average temperatures and precipitation.

33. Earth’s Seasons Seasons are short periods of climatic change caused by changes in the amount of solar radiation an area receives. Because Earth is tilted, different areas of Earth receive changing amounts of solar radiation throughout the year. Climatic Changes 3 3

34. Seasonal Changes Because of fairly constant solar radiation near the equator, the tropics do not have much seasonal temperature change. The middle latitudes, or temperate zones, have warm summers and cool winters. Spring and fall are usually mild. Climatic Changes 3 3

35. High Latitudes The high latitudes near the poles have great differences in temperature and number of daylight hours. During summer in the northern hemisphere, the north pole is tilted toward the Sun. Climatic Changes 3 3

36. High Latitudes During summer at the north pole, the Sun doesn’t set for nearly six months. During that same time, the sun never rises at the south pole. Climatic Changes 3 3

37. El Niño and La Niña El Niño (el NEEN yoh) is a climatic event that involves the tropical Pacific Ocean and the atmosphere. During normal years, strong trade winds that blow east to west along the equator push warm surface water toward the western Pacific Ocean. Climatic Changes 3 3 During El Niño years, these winds weaken and sometimes reverse.

38. El Niño and La Niña The change in winds allows warm, tropical water in the upper layers of the Pacific to flow back eastward to South America. Ocean temperatures increase by 1°C to 70°C off the coast of Peru. Climatic Changes 3 3 El Niño can affect weather patterns. It can alter the position and strength of one of the jet streams.

39. El Niño and La Niña The opposite of El Niño is La Niña. During La Niña, the winds blowing across the Pacific are stronger than normal, causing warm water to accumulate in the western Pacific. Climatic Changes 3 3

40. El Niño and La Niña Climatic Changes 3 3 La Niña may cause droughts in the southern United States and excess rain fall in the northwestern United States.

41. Climatic Change Some warm-weather fossils found in polar regions indicate that at times in Earth’s past, worldwide climate was much warmer than at present. Climatic Changes 3 3 At other times Earth’s climate has been much colder than it is today.

42. Climatic Change Sediments in many parts of the world show that several different times in the past 2 million years, glaciers covered large parts of Earth’s surface. Climatic Changes 3 3 These times are called ice ages. During the past 2 million years, ice ages have alternated with warm periods called interglacial intervals. We are now in an interglacial interval that began about 11,500 years ago.

43. What causes climatic change? Climatic Changes 3 3 Catastrophic events, including meteorite collisions and large volcanic eruptions, can affect climate over short periods of time, such as a year or several years.

44. What causes climatic change? Another factor that can alter Earth’s climate in short- or long-term changes in solar output, which is the amount of energy given off by the Sun. Climatic Changes 3 3 Changes in the Earth’s movements in space affect climate over many thousands of years, and movement of Earth’s crustal plates can change climate over millions of years.

45. Atmospheric Solids and Liquids Small solid and liquid particles always are present in Earth’s atmosphere. Climatic Changes 3 3 Some ways that particles enter the atmosphere naturally include volcanic eruptions, soot from fires, and wind erosion of soil particles. Humans add particles to the atmosphere through automobile exhaust and smoke stack emissions. These small particles can affect climate.

46. Atmospheric Solids and Liquids Mount Pinatubo in the Philippines erupted in 1991. Climatic Changes 3 3 During the eruption, particles were spread high into the atmosphere and circled the globe. Over time, particles spread around the world, blocking some of the Sun’s energy from reaching Earth.

47. Energy from the Sun If the output of radiation from the Sun varies, Earth’s climate could change. Climatic Changes 3 3 Some changes in the amount of energy given off by the Sun seem to be related to the presence of sunspots. Sunspots are dark spots on the surface of the Sun. An extremely cold period in Europe occurred between 1645 and 1715. During this time, very few sunspots appeared on the Sun.

48. Earth Movements Earth’s axis currently is tilted 23.5°from perpendicular to the plane of its orbit around the Sun. Climatic Changes 3 3 In the past, this tilt has increased to 24.5° and has decreased to 21.5° When this tilt is at its maximum, the change between summer and winter is probably greater.

49. Earth Movements Two additional Earth movements also cause climatic change. Climatic Changes 3 3 Earth’s axis wobbles in space just like the axis of a top wobbles when it begins to spin more slowly. This can affect the amount of solar energy received by different parts of Earth. Also, the shape of Earth’s orbit changes.

50. Amount of Solar Energy These movements of Earth cause the amount of solar energy reaching different parts of Earth to vary over time. Climatic Changes 3 3 These changes might have caused glaciers to grow and shrink over the last few million years.

51. Crustal Plate Movement The movement of continents and oceans affects the transfer of heat on Earth, which in turn affects wind and precipitation patterns. Climatic Changes 3 3 Through time, these altered patterns can change climate.

52. Climatic Changes Today The greenhouse effect is a natural heating process that occurs when certain gases in Earth’s atmosphere trap heat. Climatic Changes 3 3 Radiation from the Sun strikes Earth’s surface and causes it to warm. Some of this heat then is radiated back toward space. Click image to view movie.

53. Climatic Changes Today Climatic Changes 3 3 This keeps Earth warmer than it would be otherwise. Some gases in the atmosphere, known as greenhouse gases, absorb a portion of this heat and then radiate heat back towards Earth.

54. Climatic Changes Today There are many natural greenhouse gases in Earth’s atmosphere. Climatic Changes 3 3 Water vapor, carbon dioxide, and methane are some of the most important ones. Without these greenhouse gases, life would not be possible on Earth.

55. Global Warming Over the past 100 years, the average global surface temperature on Earth has increased by 0.6°C. This increase in temperature is known as global warming. Climatic Changes 3 3 Researchers hypothesize that the increase in global temperatures may be related to the increase in atmospheric carbon dioxide.

56. Global Warming If Earth’s average temperature continues to rise, many glaciers could melt. Climatic Changes 3 3 When glaciers melt, the extra water causes sea levels to rise. Low-lying coastal areas could experience increased flooding.

57. Human Activities — Burning Fossil Fuels When natural gas, oil, and coal are burned for energy, the carbon in these fossil fuels combines with atmospheric oxygen to form carbon dioxide. Climatic Changes 3 3 This increases the amount of carbon dioxide in Earth’s atmosphere.

58. Deforestation Destroying and cutting down trees, called deforestation, also affects the amount of carbon dioxide in the atmosphere. Climatic Changes 3 3 As trees grow they take in carbon dioxide from the atmosphere. When trees are cut down, the carbon dioxide they could have removed from the atmosphere remains in the atmosphere.

59. The Carbon Cycle Climatic Changes 3 3 Carbon, primarily as carbon dioxide, is constantly recycled in nature among the atmosphere, Earth’s oceans, and organisms that inhabit the land.

60. The Carbon Cycle Climatic Changes 3 3 When Earth’s climate changes, the amount of carbon dioxide that cycles among atmosphere, ocean, and land also can change.

61. The Carbon Cycle Climatic Changes 3 3 Some people hypothesize that if the Earth’s climate continues to warm, more carbon dioxide may be absorbed by oceans and land.

62. Section Check 3 3 Question 1 Short periods of climatic change caused by changes in the amount of solar radiation an area receives are called __________. A. adjustments B. El Nino C. greenhouse effects D. seasons

63. Section Check 3 3 Answer The answer is D. Because Earth is tilted on its axis, different areas of Earth receive changing amounts of solar radiation throughout the year as it revolves around the Sun.

64. Section Check 3 3 Question 2 What is the greenhouse effect?

65. Section Check 3 3 Answer The greenhouse effect is a natural heating process that occurs when gases in Earth’s atmosphere trap heat.

66. Section Check 3 3 Question 3 Destroying and cutting down trees is called __________. A. clear cutting B. deforestation C. timber management D. vandalism

67. Section Check 3 3 Answer The answer is B. Deforestation can occur in a variety of ways, including clear cutting for agricultural purposes.