1. Chapter 17 Preview Section 1 What Is Climate? Section 2 The Tropics
Section 3 Temperate and Polar Zones
Section 4 Changes in Climate
Concept Mapping

2. Section 1 What Is Climate?
Chapter 17
Bellringer
Pretend you are entering a contest for a free trip to a place with perfect climate. To win, write a description of your idea of the perfect climate in 25 words or less. Do you know of any real place where your dream climate really exists?
Record your response in your science journal.

3. Chapter 17
Section 1 What Is Climate?
Objectives
Explain the difference between weather and climate.
Identify five factors that determine climates.
Identify the three climate zones of the world.

4. Chapter 17 Climate Vs. Weather
Section 1 What Is Climate?
Climate Vs. Weather
Weather is the condition of the atmosphere at a particular time.
Climate is the average weather condition in an area over a long period of time.

5. Chapter 17
Section 1 What Is Climate?
Latitude
Solar Energy and Latitude The amount of direct solar energy a particular area receives is determined by latitude. Latitude is the distance north or south, measured in degrees, from the equator.

6. Chapter 17 Latitude, continued
Section 1 What Is Climate?
Latitude, continued
Seasons and Latitude Seasons happen because the Earth is tilted on its axis at a 23.5° angle. This tilt affects how much solar energy an area receives as Earth moves around the sun.

7. Chapter 17
Section 1 What Is Climate?

8. Chapter 17 Prevailing Winds
Section 1 What Is Climate?
Prevailing Winds
Winds that blow mainly from one direction are prevailing winds.
Prevailing winds affect the amount of precipitation that a regions receives.
The circulation of warm and cold air cause prevailing winds.

9. Chapter 17
Section 1 What Is Climate?

10. Chapter 17
Section 1 What Is Climate?
Mountains
Mountains can influence an area’s climate by affecting both temperature and precipitation.
Elevation is the height of surface landforms above sea level.
As the elevation increases, the ability of air to transfer energy from the ground to the atmosphere decreases.

11. Chapter 17 Large Bodies of Water Ocean Currents
Section 1 What Is Climate?
Large Bodies of Water
Large bodies of water can influence an area’s climate. Water absorbs and releases heat slower than land does. Because of this quality, water helps to moderate the temperatures of the land around it.
Ocean Currents
As surface currents move, they carry warm or cool water to different locations. The surface temperature of the water affects the temperature of the air above it.

12. Surface Currents and Climates
Chapter 17
Section 1 What Is Climate?
Surface Currents and Climates
Click below to watch the Visual Concept.
Visual Concept

13. Chapter 17 Climates of the World
Section 1 What Is Climate?
Climates of the World
The Earth’s three major climate zones are determined by latitude.
Climates zones are made up of different biomes. Biomes are characterized by certain types of plant and animal communities.

14. Chapter 17
Section 1 What Is Climate?

15. Chapter 17
Section 2 The Tropics
Bellringer
Imagine you are a zoologist hired to design a camel and a deer exhibit for your community's new zoo. Describe the differences between a deer and a camel. Where and in what kind of climate are you most likely to find these animals? What would you have to provide for each of these animals so they would continue to flourish?
Write your exhibit proposal in your science journal.

16. Chapter 17 Objectives Locate and describe the tropical zone.
Section 2 The Tropics
Objectives
Locate and describe the tropical zone.
Describe the biomes found in the tropical zone.

17. Chapter 17 The Tropical Zone
Section 2 The Tropics
The Tropical Zone
The region that surrounds the equator and that extends from about 23.5˚ north latitude to 23.5˚ south latitude is called tropical zone.

18. The Tropical Zone, continued
Chapter 17
Section 2 The Tropics
The Tropical Zone, continued
Tropical Rain Forests Tropical rain forests are always warm and wet. Because they are located near the equator, they receive strong sunlight year-round.
Tropical rain forests contain the greatest number of animal and plant species of any biome.

19. The Tropical Zone, continued
Chapter 17
Section 2 The Tropics
The Tropical Zone, continued
Tropical Savannas Tropical savannas, or grasslands, are composed of tall grasses and a few scattered trees. The climate is usually very warm.
Tropical savannas have a dry season that lasts four to eight months and that is followed by short periods of rain.

20. The Tropical Zone, continued
Chapter 17
Section 2 The Tropics
The Tropical Zone, continued
Tropical Deserts A desert is an area that receives less that 25 cm of rainfall per year.
Daily temperatures in tropical deserts often vary from very hot daytime temperatures to cool nighttime temperatures.

21. Chapter 17
Section 3 Temperate and Polar Zones
Bellringer
You have been selected to join an expedition to the North Pole. What kinds of gear will you need? How will you travel both to the Pole and once you arrive in the Arctic? What will you bring to eat? Will you be able to hunt? Write a description in your science journal of what activities you might engage in during an average week of your expedition.

22. Chapter 17
Section 3 Temperate and Polar Zones
Objectives
Locate and describe the temperate zone and the polar zone.
Describe the different biomes found in the temperate zone and the polar zone.
Explain what a microclimate is.

23. Chapter 17 The Temperate Zone
Section 3 Temperate and Polar Zones
The Temperate Zone
The climate zone between the Tropics and the polar zone is the temperate zone. Latitudes in the temperate zone receive less solar energy than latitudes in the Tropics do.

24. The Temperate Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Temperate Zone, continued
Temperate Forests The temperate forest biomes tend to have high amounts of rainfall and seasonal temperature differences.
Both deciduous trees and evergreen trees grow in temperate forests.

25. The Temperate Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Temperate Zone, continued
Temperate Grasslands Temperate grasslands are regions that receive too little rainfall for trees to grow. This biome has warm summers and cold winters.
Grasses are the most common kind of plant found in this biome.

26. The Temperate Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Temperate Zone, continued
Chaparrals Chaparral regions have cool, wet winters and hot, dry summers. The vegetation is mainly evergreen shrubs.
These shrubs are short, woody plants with thick waxy leaves. The waxy leaves are adaptations that help prevent water loss in dry conditions.

27. The Temperate Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Temperate Zone, continued
Temperate Deserts The temperate desert biomes tend to be cold deserts. Like all deserts, cold deserts receive less than 25 cm of precipitation yearly.
Temperate deserts can be very hot in the daytime. But, unlike hot deserts, they are often very cold at night.

28. Chapter 17
Section 3 Temperate and Polar Zones
The Polar Zone
The climate zone located at the North or South Pole and its surrounding area is called the polar zone. Polar climates have the coldest average temperatures of all the climate zones.

29. The Polar Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Polar Zone, continued
Tundra The tundra biome has long, cold winters with almost 24 hours of night. It also has short, cool summers with almost 24 hours of daylight.
In the summer, only the top meter of soil thaws. Underneath the thawed soil lies a permanently frozen layer of soil, called permafrost.

30. The Polar Zone, continued
Chapter 17
Section 3 Temperate and Polar Zones
The Polar Zone, continued
Taiga (Northern Coniferous Forest) The taiga has long, cold winters and short, warm summers.
The majority of the trees are evergreen needle-leaved trees called conifers. The needles and flexible branches allow these trees to shed heavy snow before they can be damaged.

31. Chapter 17 Microclimates
Section 3 Temperate and Polar Zones
Microclimates
The climate and the biome of a particular place can also be influenced by local conditions. Microclimate is a climate of a small area.
Cities are also microclimates. In a city, temperatures can be 1°C to 2°C warmer than the surrounding rural areas.

32. Chapter 17
Section 4 Changes in Climate
Bellringer
Imagine that the climate in the area where you live has changed so that it is now warmer than it used to be. Write down five ways how you think warmer temperatures would affect the area.
Write your answers in your science journal.

33. Chapter 17
Section 4 Changes in Climate
Objectives
Describe how the Earth’s climate has changed over time.
Summarize four different theories that attempt to explain why the Earth’s climate has changed.
Explain the greenhouse effect and its role in global warming.

34. Chapter 17
Section 4 Changes in Climate
Ice Ages
An ice age is a period during which ice collects in high latitudes and moves toward lower latitudes.
During glacial periods, enormous sheets of ice advance to cover a larger portion of the Earth.

35. Chapter 17 Ice Ages, continued
Section 4 Changes in Climate
Ice Ages, continued
Interglacial Periods Warmer times that happen between glacial periods are called interglacial periods. During an interglacial period, the ice begins to melt and the sea level rises again.
Motions of the Earth There are many theories about the causes of ice ages. The Milankovitch theory explains why an ice age alternates between cold and warm periods.

36. Chapter 17
Section 4 Changes in Climate

37. Chapter 17 Ice Ages, continued
Section 4 Changes in Climate
Ice Ages, continued
Ice Ages The Earth’s climate is further influenced by plate tectonics and continental drift. One theory proposes that ice ages happen when the continents are positioned closer to the polar regions.

38. Chapter 17 Volcanic Eruptions
Section 4 Changes in Climate
Volcanic Eruptions
Many natural factors can affect global climate. Catastrophic events, such as volcanic eruptions, can influence climate.

39. Effects of Volcanoes on Earth
Chapter 17
Section 4 Changes in Climate
Effects of Volcanoes on Earth
Click below to watch the Visual Concept.
Visual Concept

40. Chapter 17 Asteroid Impact
Section 4 Changes in Climate
Asteroid Impact
Dramatic Climatic Change Scientists believe that if an asteroid this big hit the Earth, it could change the climate of the entire world.

41. Chapter 17 The Sun’s Cycle
Section 4 Changes in Climate
The Sun’s Cycle
Some changes in the climate can be linked to changes in the sun.
The sun follows an 11-year cycle. During this cycle, the sun changes from a solar maximum to a solar minimum.
When the sun is at its solar maximum, it produces a large percentage of high-energy radiation. This increase in radiation warms the winds in the atmosphere.

42. Chapter 17 Global Warming
Section 4 Changes in Climate
Global Warming
A gradual increase in the average global temperature is called global warming.
The Earth’s natural heating process, in which gases in the atmosphere trap thermal energy, is called the greenhouse effect.
Many scientists think that if the global temperature continues to rise, the ice caps will melt and cause flooding.

43. Chapter 17 Concept Mapping
Climate
Chapter 17
Concept Mapping
Use the terms below to complete the concept map on the next slide.
ocean currents
seasons
latitude
climate
prevailing winds
curved
mountains
large bodies of water

44. Climate
Chapter 17

45. Climate
Chapter 17