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Chapter 3: Climates of the Earth

Chapter 3: Climates of the Earth

CHAPTER

Why It Matters Climate affects where and how Climates of people live. An understanding of ’s climates and the factors, both physical and human, that influence them adds to a more the Earth complete view of life on Earth.

Section 1: Earth- Relationships The physical environment affects people and their activities. Earth’s position in relation to the sun affects temperatures, and , and on Earth, which in turn influ- ence when and how people perform certain activities. Section 2: Factors Affecting Climate Physical processes shape Earth’s surface. , elevation, wind patterns, and ocean currents affect Earth’s climates. Section 3: World Climate Patterns Geographers organize Earth into regions that share common char- acteristics. Geographers classify Earth’s climate and into regions.

Geography ONLINE Chapter Overview Visit the World Geography and Cultures Web site at glencoe.com and click on Chapter Overviews—Chapter 3 to preview infor- mation about planet Earth. Monaco , , , is a popular hunting ground for polar bears.

48 Unit 1

Hans Strand/CORBIS THE WORLD 49 Chapter 3 shadow. Make a Vocabulary As you read the chapter, write a Identifying Identifying and learnBook to help you organize terms intro- the content vocabulary the climatesduced as you read about need to makeof the Earth. You may Book. more than one Vocabulary Reading and Writing You may term on each tab and its definition underneath. want to illustrate visual terms such as SECTION 1 Earth-Sun Guide to Reading

Section Preview Relationships Earth’s position in relation to the sun affects temperatures, day and From the Alps in the heart of Europe, scientists gather night, and seasons on Earth. data about melting and changes in the snow

Content Vocabulary line. Their research reveals information about the • weather (p. 51) • (p. 51) Earth’s atmosphere and the warming effects of the sun. • climate (p. 51) • (p. 51) Such dynamic relationships between the Earth and the • axis (p. 51) • greenhouse • temperature effect (p. 52) sun influence all life on Earth. (p. 51) • global warming • revolution (p. 53) Voices Around the World (p. 51) Academic Vocabulary “We marvel at the mountains, but it’s the water that everything depends on. • contrast (p. 51) . . . Snow, glaciers, permafrost, surging hot springs, aquamarine ramparts of • affects (p. 51) ice — the very capillaries of the rock itself are permeated with water. It comes • regulated (p. 52) sleeking down black rock faces, it drips into hidden cavern pools. If the Alps Places to Locate had a voice, it would be the musical notes of water. Water is what is literally • Tropic of (p. 51) holding the high mountains together, and if the ice and permafrost begin to • (p. 52) lose their grip, as is already happening, the mountains start to crumble.”

Reading Strategy — Erla Zwingle, “Meltdown: The Alps Under Pressure,” Categorizing Complete a graphic National Geographic, February 2006 organizer similar to the one below by listing the major characteristics of the and winter .

Northern Hemisphere

Summer solstice

• • • • • • • •

Hikers in the Alps

50 Unit 1

Hans Strand/CORBIS THE WORLD 51 Chapter 3 (meaning revolution, As the Earth equinox equinox Capricorn change. to complete one

Hemisphere. marks the beginning of sum-

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at 23½° N, the northernmost at 23½° N, sun.

solstice, Revolution one year

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The Earth’s revolution and its tilt cause changes The Earth’s and south of The seasons are reversed While planet Earth is rotating on its axis, it is its axis, While planet Earth is rotating on ropic of Cancer mer in the Northern point on the Earth to receive the direct rays of the of Cancer Tropic the These direct rays reach sun. bringing the about June 21, known as This date, its longest day of sunlight. the summer or trip around the that reach in the angle and amount of sunlight These changes different locations on the planet. as the sea- follow a regular progression known people on the course of a year, During sons. distinct dif- most parts of the Earth experience the daily tem- ferences in the length of days and perature as the seasons When it is spring in the Northern the . it is fall in the . Hemisphere, it When it is winter in the Southern Hemisphere, Around is summer in the Northern Hemisphere. rays fall directly on the the sun’s March 21, This day is called an Equator. “equal night”) because and nighttime hours are equal. continues its revolution around the sun, it moves continues its revolution around the sun, the rays directly strike so that eventually the sun’s T The of Cancer and Earth’s also traveling in an orbit around the sun, our near- sun, also traveling in an orbit around the a few hours more than It takes the Earth est star. 365 days the

is the

affects eather W eather sun. day. W time. night. Rotation Did you know that as you Did you know

people in the dry, desert people in the dry,

YOU the measure of how hot or cold a

weather. The relationship between the Earth the Earth between The relationship contrast,

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is the term for the weather patterns thatis the term for the weather patterns a e d IIdea

N I — an running from the North an imaginary —

A Whether or not a particular place on Earth Whether or not a particular place on Earth For this reason, the angle of tilt For this reason, Earth’s tilt is one reason for variations in sun- Earth’s Climate is often confused with weather, which confused with weather, Climate is often Climate MAIN MMAIN turns first one hemisphere and then the other alternating between the light of toward the sun, day and the darkness of are Fahrenheit (°F) and Celsius (°C). receives light also depends on the side of the Earth rotates on its planet that is facing the sun. every 24 making one complete rotation axis, the Earth Rotating from west to east, hours. place is. Areas that receive a large amount of directAreas that receive place is. sunlight have warmer temperatures than places is Temperature that receive little direct sunlight. The usually measured in degrees on a set scale. most common scales for measuring temperature Earth’s Tilt and relationship causes night and relationship causes and the sun affects climate, which influences life on which influences affects climate, and the sun ways. Earth in dramatic AND GEOGRAPHY class it is nighttime in some are sitting in geography Read to learn how the Earth-sun parts of the world? Climate and and Climate temperature ter— is currently tilted at an angle of about angle of about is currently tilted at an ter— not all of the tilt of this axis, Because 23½°. amount of places on the planet receive the same direct sunlight at the same light. As the diagram above shows, the Earth’s the Earth’s As the diagram above shows, light. axis cen- planet’s Pole to the through the a limited period of time. When people look out When of time. a limited period the news to see whether the window or watch are they they need umbrellas or sunscreen, checking the is a short-term aspect of climate. of climate. is a short-term aspect atmosphere in one place during condition of the time. People in Seattle, Washington, for example, for example, Washington, in Seattle, People time. wet the rainy, frequently use umbrellas because of In climate. sunscreen must use Arizona, climate of Phoenix, to protect themselves from the an area typically experiences over a long period ofan area typically experiences over By about September 23, the Earth has revolved so that the sun’s rays directly strike the Equator The Greenhouse Effect again. This equinox marks the beginning of fall in the Northern Hemisphere. Gradually the sun’s MMAINAIN IIdeadea The natural process of the greenhouse direct rays strike farther south, reaching their effect has been influenced by human activity. southernmost latitude of 23½° S, at the Tropic of GEOGRAPHY AND YOU Have you heard news Capricorn about December 22. The winter sol- accounts of the dangers of global warming? Read to stice is the day of shortest daylight in the Northern learn how global warming can affect Earth. Hemisphere, beginning the of winter. The Poles The most dramatic variation in the Even on the sunniest days in the warmest cli- amount of sunlight occurs at the Poles. For six mates, only part of the sun’s radiation passes months of the year, one Pole is tilted toward the through the Earth’s atmosphere. The atmosphere sun and receives continuous sunlight, while the reflects some radiation back into space. Enough other Pole is tilted away from the sun and radiation, however, reaches the Earth to warm receives little to no sunlight. the land, water, and air. At the , the sun never sets from Because the atmosphere traps some heat and about March 20 to September 23. At the South keeps it from escaping back into space too Pole, continuous daylight lasts from about quickly, Earth’s atmosphere is like the glass in a September 23 to March 20. The tilt of the Earth’s greenhouse — it traps the sun’s energy for grow- axis as it revolves around the sun causes this natu- ing plants even in cold weather. Without this ral phenomenon, known as the sun. The greenhouse effect, the Earth would be too cold occurrence of the midnight sun goes almost unno- for most living things. ticed in sparsely populated . Parts of In order to support plant growth, conditions northern (including ) and in a greenhouse must be regulated. If too much northern Europe in the , however, have become popular tourist destinations as lands of the midnight sun.

Regions What factor distin- 1. Regions Why are the seasons reversed in the guishes weather from climate? Northern and Southern Hemispheres? 2. Place Explain the difference between the and the solstices.

The Earth’s Seasons Use StudentWorks™ Plus or glencoe.com.

52 Unit 1 THE WORLD 53 Chapter 3 effects. Explain the differences in the What would you pack if you were Review the text in Section 1 about global ONLINE To review this section, go to Study the diagram of the Earth’s seasons

and click on Study Central. Human-Environment Interaction

What effects does the Earth’s tilt on its axis have on What effects does the Earth’s tilt on its axis Geography Study Central™ glencoe.com the Equator? The Tropics of Cancer and Capricorn? the Equator? The Tropics of Cancer and visiting in December? visiting Argentina in which may be affected. which agriculture may be weather you would expect in Alaska and in Florida. warming. Then write a paragraph explaining the ways in your daily life? your daily on page 52. In what months do the sun’s rays directly strike Comparing and Contrasting Analyzing Information Analyzing Visuals Expository Writing

4. 5. 6. 7. 8. Writing About Geography Writing About Critical Thinking Critical

Scientists do not all agree on the nature of nature of Scientists do not all agree on the that it is too early to forecast future that it is too early to forecast future global warming and its effects. Some claim that global warming and its effects. is causing activity, not human a natural cycle, that the evi- Others claim rising temperatures. and dence for global warming is inconclusive How has human activity contributed to global to global How has human activity contributed warming? is is

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heat. out. created. levels has coin- before.

2 atmospheric com-

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global warming REVIEW known as

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1 absorb the heat reflected by the Earth andabsorb the heat reflected

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ed to be caused in part by human activities, activities, ed to be caused in part by human ) 2 Earth-Sun Relationshipon Climate Effects Tilt Rotation Revolution warming. process has been influenced by human activity. revolution, equinox, solstice, greenhouse effect, global revolution, equinox, solstice, greenhouse effect, ship between the Earth and the sun affects climate. List effects on climate. effects on characteristics of the Earth-sun relationship and describe their Explain the greenhouse effect. Then describe how this natural Use a chart like the one below to describe how the relation- Explain the significance of: weather, climate, axis, temperature, Explain the significance of: weather, climate, Some scientists report that global warming willSome scientists report that global Many scientists, however, claim that in recent claim however, Many scientists, The greenhouse effect of Earth’s atmosphere fol- atmosphere effect of Earth’s The greenhouse

Main Ideas Main 2. 3. 1. Vocabulary areas may even become drier than areas may even become drier than make weather patterns more extreme. Water, for Water, make weather patterns more extreme. evaporate more rapidly from oceans, will example, Rapid increasing humidity and rainfall generally. will cause however, water evaporation from soil, Some . land to dry out more quickly between believ and natural gas. oil, such as the burning of coal, a green- These fossil fuels release carbon dioxide, that traps more in the atmosphere house gas, radiate it back again so that a balance is radiate it back again decades a rise in atmospheric CO decades a rise in atmospheric cided with a general rise in global temperatures. rise in global temperatures. cided with a general This trend Clouds and greenhouse gases Clouds and greenhouse vapor and carbon dioxideponents such as water (CO lows some of the same general rules. Normally, Normally, rules. of the same general lows some ofjust the right amount provides the atmosphere The on the planet. to promote life insulation reaches the radiation that of the sun’s 50 percent or heat. into infrared radiation, Earth is converted heat escapes, the plants will freeze. If too much much If too freeze. plants will the escapes, heat or dry will wilt plants the is trapped, heat

SECTION SECTION 2 Factors Guide to Reading

Section Preview Affecting Climate Factors such as latitude, elevation, wind patterns, and ocean currents Latitude, wind patterns, ocean currents, and landforms affect Earth’s climates. create extremely cold temperatures and climate condi-

Content Vocabulary tions in Antarctica. Only a few brave researchers and • prevailing wind • El Niño (p. 58) scientists spend months at a time in one of the last wil- (p. 56) • windward derness places on Earth. Antarctica provides them with • Coriolis effect (p. 59) (p. 56) • leeward (p. 59) a wonderful natural laboratory in which to study Earth. • doldrums • (p. 57) (p. 59) Voices Around the World • current (p. 57) Academic Vocabulary “There are no places left like Antarctica: a wilderness continent that offers scien- • retains (p. 55) tists unique views of the workings of the Earth. . . . [W]inds roll down the polar • creates (p. 56) plateau at speeds up to 180 miles an hour. Some of the world’s most violent • factors (p. 57) squalls and mountainous seas batter the lonely archipelagoes off the Antarctic Places to Locate Peninsula. . . . Antarctica influences weather patterns across the Southern • low (p. 55) Hemisphere, shapes ocean currents throughout the world, and acts as a • high latitudes (p. 55) sobering litmus for humanity’s use and abuse of the planet.” • (p. 55) • (p. 55) — Roff Smith, • midlatitudes (p. 55) “Frozen Under,” National Geographic, Reading Strategy December 2001 Organizing As you read about fac- tors affecting Earth’s climate, create a web diagram like the one below by listing factors that cause both winds and ocean currents.

Winds and Ocean Currents

Adélie penguin, Antarctica

54 Unit 1

Tim Davis/Stone Collection/Getty Images THE WORLD 55 Chapter 3 Average 39°F (3°C) 81°F (27°C) 81°F 58°F (14°C) 67°F (19°C) 77°F (25°C) Temperature lowlands. 0°09´ S S 1°19´ 3°19´ S 3°19´ 3°09´ S 36°55´ E 29°19´ E 37°57´ N 37°57´ 78°29´ W 59°59´ W 107°49´ W What happens to tem-

less heat. As elevation As elevation less heat.

Regions retains (84 m)

(782 m) 2,568 ft. 2,568 ft. 8,760 Elevation Latitude & & Elevation Latitude (2,811 m) (1,623 m) (2,670 m) The Influence of Elevation on Temperature The Influence of Elevation on www.weatherbase.com arm/hot and cool/cold air masses affect mid- affect air masses cool/cold and arm/hot At all latitudes, elevation influences climate climate elevation influences At all latitudes, W Sunlight is bright in Quito and other places Quito, Ecuadorft. 9,223 Nairobi, Kenyaft. 5,327 Bujumbura, Burundi Telluride, Colorado Manaus, Brazilft. 276 Source: perature as elevation increases? Elevation Equator. However, Quito lies in the at an Quito lies in the However, Equator. so (2,743 m), elevation of more than 9,000 feet about 32°F average temperatures there are (18°C) cooler than in the coastal because of the relationship between the eleva- because of the relationship The table and its temperature. tion of a place elevation can influence tem- below shows how atmo- The Earth’s perature regardless of latitude. Thinner air is sphere thins as altitude increases. less dense and decrease by about 3.5°F temperatures increases, This effect m). (1.9°C) for each 1,000 feet (305 in Ecuador, For example, occurs at all latitudes. nearly on the the city of Quito (KEE•toh) is latitude weather throughout the year. Although the year. throughout weather latitude near the air masses from wet tropical, warm, still they are summer, predominate in Equator of the they are the source In fact, winter. present in win- receive during snow the midlatitudes rain and this part of theair masses bring Cool/cold ter. in humid weather the hot, world its relief from as well as the cold of winter. summer, bright sunlight, the world’s highest mountains— the world’s bright sunlight, for example—are cold, Alps, Andes and the the snowy places year-round. with high elevation because the thinner atmo- Even in sphere filters fewer rays of the sun. (latitude

year. year. Earth. receives. (latitude 66½° N) When either the When either the This zone includes

changes. Did you know that someDid you know that Antarctic Circle

patterns. between 30° N and 60° N in

YOU Arctic Circle low latitudes. low high latitudes. Latitude and elevation affect the angle elevation affect Latitude and a Climate e d Latitudes IIdea

midlatitudes, N I climates. A The most variable weather on Earth is found The Earth’s polar areas, which stretch from which stretch from polar areas, The Earth’s Between 30° S and 30° N latitude is a zone Between 30° S and 30° N latitude During the Earth’s annual revolution around During the Earth’s ropic of Cancer. Portions of the low latitudes Portions ropic of Cancer. MAIN MMAIN Midlatitudes High Latitudes Low a day for six months? Read to learn how latitudea day for six months? of sun a place affects the amount and and on rays and temperatures of the sun’s GEOGRAPHY AND daylight nearly 24 hoursparts of the Earth experience Latitude, Elevation, Elevation, Latitude, in the from north of the called the is tilted Northern or the Southern Hemisphere area receives nearly its polar toward the sun, From about sunlight. but indirect, continuous, the polar area March 21 to about September 23, 60° N to 90° N and from 60° S to 90° S, are S to 90° S, 60° N to 90° N and from 60° known as the in a regular pattern. This pattern can be corre- in a regular pattern. of latitude to describe or zones, lated with bands, cli- each latitude zone, Within climate regions. mate follows general the sun, the sun’s direct rays fall upon the planet direct the sun’s the sun, latitudes generally have a — one — latitudes generally have a temperate climate with — that ranges from fairly hot to fairly cold dramatic seasonal weather the Northern Hemisphere and between 30° S the Northern Hemisphere and between 30° S mid- The and 60° S in the Southern Hemisphere. experiences continuous daylight or . The experiences continuous daylight or twilight. polar area south of the 66½° S) experiences continuous daylight or twi- light for the other six months of the Places located in the low latitudes have warm to Places located in the low latitudes hot the Tropic of Capricorn, the Equator, and the Equator, the of Capricorn, Tropic the T year-round. receive the direct rays of the sun World Zones of Latitude and Wind Patterns

Winds and Ocean Wind Patterns Winds blow because of temperature differences Currents on Earth’s surface, with tropical air moving toward the Poles and polar air moving toward MMAINAIN IIdeadea Wind and water combine with the the Equator. Global winds blow in fairly constant effects of the sun to influence Earth’s weather and patterns called prevailing winds, as shown on the climate. map above. The direction of prevailing winds is GEOGRAPHY AND YOU How does wind affect the determined by latitude and is affected by the weather in your community? Does it bring cold air or Earth’s movement. Because Earth rotates to the warm air? Read to learn about the patterns of global east, the global winds are displaced clockwise in winds and ocean currents that affect climate. the Northern Hemisphere and counterclockwise in the Southern Hemisphere. This phenomenon, Air moving across the surface of the Earth is called the Coriolis effect, causes prevailing winds called wind. Winds occur because sunlight heats to blow diagonally rather than along strict north- the Earth’s atmosphere and surface unevenly. south or east-west directions. Rising warm air creates areas of low pressure, Winds are often named for the direction from and sinking cool air causes areas of high pres- which they blow, but they sometimes were given sure. The cool air then flows in to replace the names from the early days of sailing. Named for warm rising air. These movements over the their ability to move trading ships through the Earth’s surface cause winds, which distribute the region, the prevailing winds of the low latitudes sun’s energy around the planet. are called . They blow from the north-

56 Unit 1 World Ocean Currents

1. Regions What air currents flow over the midlatitudes? 2. Movement How do ocean currents develop? How is this process east toward the Equator from about latitude similar to the development of wind patterns? 30° N and from the southeast toward the Equator from about latitude 30° S. Westerlies are the pre- Use StudentWorks™ Plus or glencoe.com. vailing winds in the midlatitudes, blowing diago- nally west to east between about 30° N and 60° N and between about 30° S and 60° S. In the high To lighten the load so the ships could take latitudes, the polar easterlies blow diagonally east advantage of the slightest breeze, sailors would to west, pushing cold air toward the midlatitudes. toss excess cargo and supplies overboard, includ- ing livestock being carried to colonial settle- The ments. This practice gave rise to the name by which the calm areas at the edges of the Tropics At the Equator, global winds are diverted north are known — the horse latitudes. and south, leaving a narrow, generally windless band called the doldrums. Two other narrow bands of calm air encircle the globe just north of Ocean Currents the and just south of the Tropic Just as winds move in patterns, cold and warm of Capricorn. In the days of wind-powered sail- streams of water, known as currents, move ing ships, crews feared being stranded in these through the oceans. Ocean currents are caused by windless areas. With no moving air to lift the many of the same factors that cause winds, includ- sails, ships were stranded for weeks in the hot, ing the Earth’s rotation, changes in air pressure, still weather. Food supplies dwindled, and perish- and differences in water temperature. The Coriolis able cargoes spoiled as the ships sat. effect is also observed in ocean currents.

Chapter 3 57 As ocean currents circulate, cold water from El Niño (ehl NEE•nyoh). It is a periodic change in the polar areas moves slowly toward the Equator, the pattern of ocean currents, water temperatures, warming as it moves toward the low latitudes. and weather in the mid-Pacific region. This water forms the warm ocean currents. The El Niño does not occur every year, but its warm water, in turn, moves away from the frequency appears to have increased over the last Equator, cooling as it nears the polar areas. 25 years. In an El Niño year, the normally low Ocean currents affect climate in the coastal lands atmospheric pressure over the western Pacific along which they flow. Cold ocean currents cool rises, and the normally high pressure over the the lands they pass. Warm ocean currents bring eastern Pacific drops. This reversal causes the warmer temperatures. For example, the North trade winds to diminish or even to reverse direc- Atlantic Current flows near western Europe. This tion. The change in wind pattern reverses the current gives western Europe a relatively mild cli- equatorial ocean currents, drawing warm water mate in spite of its northern latitude. from near Indonesia east to Ecuador, where it spreads along the coasts of Peru and . Weather and the Water Cycle Changing air pressures resulting from El Niño Wind and water work together to affect weather influence climates around the world. Precipitation in another important way. Driven by temperature, increases along the coasts of North and South condensation creates precipitation — moisture fall- America, warming winters and increasing the risk ing to the Earth in the form of rain, sleet, hail, or of floods. In Southeast Asia and , snow. The sudden cloudburst that cools a steamy and occasional massive fires occur. summer day is an example of how precipitation Scientists are not sure what causes El Niño or both affects and is affected by temperature. Water why it appears to be occurring more frequently. vapor forms in the atmosphere from evaporated Preliminary studies have linked it to global surface water. As rising air cools when elevation warming. The costs in human and economic increases, the water vapor condenses into liquid terms of the weather catastrophes associated droplets, forming clouds. Further cooling causes with El Niño make learning more about this cli- rain to fall, which can help lower the temperature matic event vitally important. on warm days. Place What happens to global winds at the Equator? El Niño Climate is also affected by recurring phenomena, or events, that alter weather patterns. The most famous of these recurring climatic events is 1. Human-Environment Interaction How might El Niño impact the lives of people in North America? The Influence of El Niño 2. Place What happens to the water temperatures and wind patterns in an El Niño year?

58 Unit 1 THE WORLD 59 Chapter 3 side of

ain shadow. r leeward, How does the presence of What happens to What happens to

Both Quito, Ecuador, and Singapore, ranges.

precipitation? Study the map of wind currents on ONLINE To review this section, go to

Study the maps of wind patterns and ocean

and click on Study Central. Movement

Describe the general differences in climate Describe the general differences in climate side — the side of the mountain range

Geography Study Central™ glencoe.com tudes. Write a paragraph explaining what might happen as between the low latitudes and the midlatitudes. between the low latitudes and the page 56. Suppose you are on a ship sailing in the low lati- mountain ranges influence climate? mountain ranges influence you drift near the Equator. contribute to Quito’s lower average annual temperature? contribute to Quito’s lower average annual currents on pages 56–57. Describe the patterns of warm currents Singapore, are located near the Equator. What factor may Singapore, are located near the Equator. What and cold currents on both maps. Are they similar or different? and cold currents on both maps. Are they similar or Analyzing Information Identifying Cause and Effect Analyzing Visuals Expository Writing

8. 6. 7. 9. 5. Writing About Geography Writing About Critical Thinking

winds after they release windward After the precipitation is facing the wind. become warmer and drier as winds released, or they descend on the opposite, dry air produces little The hot, the mountains. a precipitation in an effect known as causes dry The rain shadow effect often areas — and even deserts — to develop on the ward sides of mountain lee- Do you live near moun- Do you live near climate. prevailing wind, Coriolis effect,

patterns. YOU REVIEW Landforms and bodies of water influ- and bodies of Landforms 2 a e Location Effect d IIdea

N I Low latitudes High latitudes Midlatitudes Elevation A influence Earth’s weather and climate? shadow. doldrums, current, El Niño, windward, leeward, rain doldrums, current, El Niño, windward, leeward, elevation affect the angle of the sun’s rays and temperatures on Earth. climate patterns. Explain the significance of: Explain how landforms and bodies of water influence Earth’s Use a table like the one below to explain how latitude and How do wind and water combine with the effects of the sun to Mountain ranges, too, influence precipitation too, Mountain ranges, The climates of places located at the same lati- The climates of places

MAIN MMAIN Main Ideas Main 1. 3. 4. 2. Vocabulary

these features can affect these features can Climate climate ence Earth’s GEOGRAPHY AND of water? Read to find out how tains? A large body Landforms and and Landforms and affect climate. As the diagram shows, winds winds As the diagram shows, and affect climate. a mountain are pushed upward when they meet The rising air cools and releases most of range. on the its moisture in the form of precipitation bodies of water, for example, are slower to heat for example, bodies of water, water tempera- As a result, land. and to cool than than landtures are more uniform and constant Coastal lands receive the benefit of temperatures. experience less this moderating influence and areas. changeable weather than do inland tude can be very different, depending on the pres- different, tude can be very Large certain physical features. ence or absence of SECTION SECTION 3 World Climate Guide to Reading

Section Preview Patterns Geographers classify Earth’s climate and vegetation into regions. Recurr- Ordinary climate patterns vary from region to region. ing climate phenomena influence However, factors such as winds and air pressure can cre- climate patterns. ate pockets of dramatic climate. For example, most of Content Vocabulary Australia has a dry climate, but during the summer the • natural • mixed forest trade winds meet, creating intense thunderstorms and vegetation (p. 62) (p. 61) • (p. 62) bringing to the continent’s northern coast. • oasis (p. 61) • permafrost • coniferous (p. 63) Voices Around the World (p. 62) • hypothesis • deciduous (p. 64) “Here at last, in Weipa, was the wet I’d been looking for — the lush growth (p. 62) • smog (p. 64) along the shore, the brooding thundery skies, the heavy curtains of rain. Nearly Academic Vocabulary three feet of rain had fallen here in the past month, and more drenchings were • widespread (p. 61) on the way. ‘All this can get to be really depressing,’ a woman named Lorisa • exceeds (p. 61) Morgan told me one when I dropped by the community center and • consists (p. 61) thrift shop. ‘You get so tired after a while of mold growing on everything. You Places to Locate want to go out for a nice dinner? First you have to • Tropics (p. 61) clean the mold off your belt and shoes. We have to • (p. 61) store our videos and computer disks in the refrig- Reading Strategy erator to keep the mold from ruining them.’” Organizing Complete a graphic organizer similar to the one below — Roff Smith, “The Wet Down Under,” by filling in a brief description of National Geographic, November 2004 each climate region.

Climate Description Tropical Dry Midlatitude Flooding in , Australia High latitude Highland

60 Unit 1

Vivien Jones/AP Images Dry areas with sparse plant life are called Climate Regions deserts. Yearly rainfall in deserts seldom exceeds 10 inches (about 25 cm), and temperatures vary MMAINAIN IIdeadea Geographers divide the Earth into widely from the heat of day to the cool of night regions that have similar climates. and from season to season. Desert climates GEOGRAPHY AND YOU Does it rain much where occur in just under one-third of the Earth’s total you live? Or is it very cold with lots of snow? Read land area. The Sahara alone extends over almost to learn about the climate region where you live. the entire northern one-third of the African continent. Climates are organized into regions — tropical, The natural vegetation of deserts consists of dry, midlatitude, high latitude, and highland. But scrub and cactus, plants that tolerate low and since climates can vary within these broad regions, unreliable precipitation, low humidity, and wide geographers further divide the major regions into temperature ranges. In some desert areas, under- smaller ones. Each of these divisions has its own ground springs may support an oasis, an area of characteristic soils and natural vegetation — the lush vegetation. Some deserts have dunes or plant life that grows in an area where the natural rocky surfaces, and others have fertile soil that environment is unchanged by human activity. can yield crops through irrigation. Often bordering deserts are dry, largely tree- Tropical Climates less grasslands called steppes. Yearly rainfall in Tropical climates are found in or near the low steppe areas averages 10 to 20 inches (25 to 51 latitudes — the Tropics. The two most wide- cm). The world’s largest steppe stretches across spread kinds of tropical climate regions are eastern Europe and western and central Asia. tropical wet and tropical dry. Steppes are also found in North America, South Hot and wet throughout the year, tropical wet America, , and Australia. climates have an average temperature of 80°F (27°C). The warm, humid air is saturated with moisture, producing rain almost daily. Yearly Latitude, Climate, and Vegetation rainfall averages about 80 inches (203 cm). This continual rain tends to leach, or draw out, nutri- ents from the soil in these climates. Wildlife is also abundant. Tropical rain forest vegetation grows thickly in layers. Tall trees form a canopy over shorter trees and bushes. Shade-loving plants grow on the trees. The world’s largest tropical rain forest is in the Amazon River basin. Similar climate and vegetation exist in other parts of , the Caribbean, Asia, and Africa. Tropical dry climates have dry winters and wet , accompanied by high year-round tem- peratures. In the , the ground is covered with clumps of coarse grass. Fewer trees exist in these regions, also called savannas, than in the rain . Tropical savannas are found in Africa, Central and South America, Asia, and Australia. Dry Climates 1. Regions How do changes in temperature and moisture affect Geographers have identified two types of dry vegetation? climates, based on the vegetation in each. Both 2. Place What sort of temperatures would you expect to find in a desert and steppe climates occur in low latitudes temperate grassland? A rain forest? and midlatitudes.

Chapter 3 61 Midlatitude Climates The midlatitudes include four temperate cli- with similar climate and vegetation. Such areas mate regions. Midlatitude climates experience include southwest Australia. variable weather patterns and seasonal changes In the southeastern , a humid sub- that give rise to a variety of natural vegetation. tropical climate brings short, mild winters and Along western coastlines, between the latitudes nearly year-round rain. The wind patterns and of 30° N and 60° N and 30° S and 60° S, are re gions high pressure related to nearby oceans keep with a marine west coast climate. For example, the humidity levels high in these areas. Vegetation Pacific coast of North America has a marine west consists of , or inland grasslands, and for- coast climate. Ocean winds bring cool summers ests of evergreen and deciduous trees. and cool, damp winters. Abundant rainfall sup- In some midlatitude regions of the Northern ports the growth of both coniferous and deciduous Hemisphere, landforms influence climate more trees. Coniferous trees, most of which are ever- than winds, precipitation, or ocean temperatures greens, have cones. Deciduous trees, most of which do. Humid continental climate regions do not have broad leaves, change color and drop their experience the moderating effect of ocean winds leaves in autumn. Typical of marine west coast cli- because of their northerly continental, or inland, mates are mixed forests with both kinds of trees. locations. The farther north one travels in these Lands surrounding the Mediterranean Sea humid continental areas, the longer and more have mild, rainy winters and hot, sunny sum- severe are the snowy winters, and the shorter and mers. The natural vegetation includes thickets of cooler are the summers. Vegetation in humid con- woody bushes and short trees known as tinental regions is similar to that found in marine Mediterranean scrub. Geographers classify as west coast areas, with evergreens outnumbering Mediterranean any coastal midlatitude areas deciduous trees in the northernmost areas.

World Climate Regions

62 Unit 1 THE WORLD 63 . Chapter 3 ice cap ice cap regions? glencoe.com or Plus

What happens as you What happens as you

StudentWorks™ Regions

Climates Use Which type of climate and vegetation is Why does the amount of vegetation found only along coastal areas? found only along coastal decrease as you move toward higher latitudes? decrease as you move toward higher 2. Location 1. Regions High mountain areas, even along the Equator, even along the Equator, High mountain areas, Snow and ice, often more than 2 miles (3 km) miles (3 than 2 more often and ice, Snow Highland Highland move north through humid continental share some of the same characteristics of high- share some of the because of the thinning of thelatitude climates The higher the eleva- altitudes. atmosphere at high vegeta- Natural the cooler the temperatures. tion, Mixed forests lie at elevation. tion also varies with Higher up are mead- ranges. the bases of mountain and wildflowers. shrubs, ows with small trees, thick, constantly cover the surfaces of surfaces cover the constantly thick, vegetationthe only form of Lichens are regions. where monthly areas, survive in these that can freezing. average below temperatures subarctic subarctic limited. climate regions. climate regions. tundra tundra Climates World Natural Vegetation Regions World Natural Vegetation evergreens. Brief summer growing seasons may Brief summer growing

inter darkness and bitter cold last for several inter darkness and bitter cold last Just south of the Arctic Circle lie the Arctic Circle of the Just south In high-latitude climates, freezing tempera- freezing climates, In high-latitude Closer to the Poles are Closer to the Poles High-Latitude High-Latitude support needled support needled regions have the world’s widest temperature widest temperature world’s regions have the to summer by as varying from winter ranges, subarctic, In parts of the much as 120°F (49°C). of surface soil thaws each sum- only a thin layer or subsoil, Below it is permanently frozen mer. permafrost. tures are common throughout the year because the year because common throughout tures are the As a result, of direct sunlight. of the lack is and variety of vegetation amount are bitterly cold, here Winters climate regions. Subarctic short and cool. and summers are subarctic. Trees cannot establish roots, so vege- roots, cannot establish Trees subarctic. short grasses, very tation is limited to low bushes, kuhns). lichens (LY• and mosses, W indirect rays during long months and the sun’s The effects. summer days have limited warming than in the layer of thawed soil is even thinner sunlight back into space, cooling the atmosphere Climate Changes and lowering surface temperatures. Human interaction with the environment also MMAINAIN IIdeadea Climate changes over time. Although affects climate. Burning fossil fuels releases gases the causes of change are unclear, evidence sug- that mix with water in the air, forming acids that gests that human activity has influenced some of fall in rain and snow. Acid rain can destroy for- the changes. ests. Fewer forests may result in climatic change. GEOGRAPHY AND YOU Does your community The exhaust released from burning fossil fuels in have problems with smog? Read to learn how automobile engines and factories is heated in the human activity can influence climate change. atmosphere by the sun’s ultraviolet rays, forming smog, a visible chemical haze in the atmosphere that endangers people’s health. Other human- Climates change gradually over time, although driven changes result from dams and river diver- the causes of these changes are unclear. Scientists sions. These projects, intended to supply water to search for answers by studying the interrelation- dry areas, may cause new areas to flood or to dry ships among ocean temperatures, greenhouse out and may affect climate over time. gases, wind patterns, and cloud cover. During the last 1 to 2 million years, for exam- Human-Environment Interaction ple, the Earth passed through four ice ages, eras How does the burning of fossil fuels create smog? when glaciers covered large areas of the planet’s surface. One hypothesis, or scientific explana- Geography ONLINE tion, for these ice ages is that the Earth absorbed Student Web Activity Visit the World Geography less solar energy because of variations in the and Cultures Web site at glencoe.com and click on sun’s output of energy or because of variations Student Web Activities—Chapter 3 for an activity about in the Earth’s orbit. Another hypothesis suggests global climate change. that dust clouds from volcanic activity reflected

SECTION 3 REVIEW Vocabulary Critical Thinking 1. Explain the significance of: natural vegetation, oasis, conifer- 4. How are the five major climate regions related to ous, deciduous, mixed forest, prairie, permafrost, hypothesis, the three zones of latitude? smog. 5. Comparing and Contrasting What factors account for the similarities and differences between the subdivisions in tropi- Main Ideas cal climate zones? 2. Describe one hypothesis for climate change. Then list exam- 6. Drawing Conclusions What are the two main categories of ples of human activities that affect climate. factors causing climate change? 3. Create a table like the one below to show how geographers 7. Analyzing Visuals Study the map of world natural vegetation divide the Earth into regions with similar climates. Add infor- regions on page 63. What vegetation type dominates ? mation and a brief description about each of the world’s cli- ? mate regions. Writing About Geography Earth’s Climates Climate Region Features 8. Summary Writing On the map of world climate regions on page 62, locate the climate regions for Tashkent, Cape Town, Lima, Chicago, London, and Jakarta. Then write a paragraph summarizing the relationship between climate and settlement.

Geography ONLINE Study Central™ To review this section, go to glencoe.com and click on Study Central.

64 Unit 1 THE WORLD . 65 glencoe.com Chapter 3 by downloading quizzes by downloading your to and flashcards PDA from Study anywhere, anytime anywhere, Study LIMATE C FFECTING A Inuit boy with sled dogs during midnight sun, Canada Inuit boy with sled dogs during midnight sun, glacier breaking into lake, Argentina the Equator, the cooler the climate. landscape. Nino, and large currents, recurring phenomena such as El landforms. ACTORS • Latitude plays a major role in climate. The farther one gets from • High elevations are generally cooler than the surrounding • Other factors that help determine climate are wind and water F VISUAL SUMMARY SUMMARY VISUAL ATTERNS P ELATIONSHIPS 3 R N LIMATE Latitude and Temperature C -SU ORLD (bkgd)Robert Laberge/Getty Images, (tr)Rob Howard/CORBIS, (br)Keren Su/CORBIS processes and human activity. latitude and highland climates. Each of these can be broken down into smaller categories. vegetation. around the world. Earth’s surface to the sun. the relationship of the When it is directly over the Tropic in the Northern Hemisphere. in the Northern Hemisphere. of Capricorn, it is winter ARTH W • The major climate regions are tropical, dry, midlatitude, high • Each climate region has its own characteristic natural • Climate patterns change over time as a result of both natural • Geographers divide the world into major climate regions. • tilt and revolution cause the seasons by changing The Earth’s • summer is directly over the Tropic of Cancer it is When the sun • patterns of the Earth to the sun affects climate The relationship E CHAPTER CHAPTER 3 STANDARDIZED TEST PRACTICE

TESTTEST-TAKING TAKING TIP

If you fi nd a question that is more diffi cult for you, skip it and go on to answer the other questions. Then return to the more diffi cult question.

Reviewing V ocabulary Reviewing Main Ideas Directions: Choose the word or words that best complete the Directions: Choose the best answers to the following questions. sentence. Section 1 (pp. 50–53) 1. Day-to-day conditions of the atmosphere make up . 5. Why is the greenhouse effect necessary to life? A weather A People’s activities increase the greenhouse effect. B climate B Without the greenhouse effect, Earth would be too cold C axis for life. D equinox C Farmers grow crops in greenhouses. D Scientists are afraid that climate change will harm society.

2. Long-term atmospheric conditions that people can expect to be generally true make up . A weather B climate Section 2 (pp. 54–59) C solstice 6. During El Niño years, weather in western South America D tilt becomes . A hotter and drier B warmer and rainier 3. Because of , winds tend to blow diagonally rather than from due north, south, east, or west. C colder and rainier A weather D colder and drier B rain shadow C the Coriolis effect D El Niño

Section 3 (pp. 60–64) 4. Grasslands in midlatitude climates are called . 7. Each climate region has its own kind of . A savannas A rock structure B mixed vegetation B tectonic plate C prairies C natural vegetation D tundras D Coriolis effect

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66 Unit 1 ASSESSMENT

Critical Thinking Document-Based Questions Directions: Choose the best answers to the following questions. Directions: Analyze the document and answer the short-answer questions that follow the document. 8. How do human activities impact climate? A The sun may give off varying amounts of solar energy. The United Nations Framework Convention on Climate Change went into force in 1994. The excerpt below explains why its B Volcanic eruptions may increase cloud cover. framers believed it was necessary. C People add gases to the atmosphere by burning fossil fuels. D Scientists do research to learn what causes climate change. The Parties to this Convention, Acknowledging that change in the Earth’s climate and its Base your answer to question 9 on the map and on your knowledge adverse effects are a common concern of humankind, of Chapter 3. Concerned that human activities have been substantially Temperature Variation increasing the atmospheric concentrations of greenhouse gases, that these increases enhance the natural greenhouse effect, and that this will result on average in an additional warming of the Earth’s surface and atmosphere and may adversely affect natural ecosystems and humankind, . . . Acknowledging that the global nature of climate change calls for the widest possible cooperation by all countries and their participation in an effective and appropriate international response, in accordance with their common but differentiated responsibilities and respective capabilities and their social and economic conditions, . . . Affi rming that responses to climate change should be coordi- nated with social and economic development in an integrated N manner with a view to avoiding adverse impacts on the latter, W E taking into full account the legitimate priority needs of devel- oping countries for the achievement of sustained economic S growth and the eradication of poverty. . . .

10. Why were the writers of the framework concerned about PACIFIC ATLANTIC climate? OCEAN OCEAN 11. What attitude does the framework take regarding social and economic development?

Extended Response 9. Going from the Equator to the North Pole, average temperatures______. 12. Describe the infl uence humans have upon climate change? A become progressively warmer STOP B become warmer, then colder C become colder, then warmer D become progressively colder Geography ONLINE For additional test practice, use Self-Check Quizzes— Chapter 3 on glencoe.com.

Need Extra Help? If you missed questions. . . 1 2 3 4 5 6 7 8 9 10 11 12 Go to page. . . 51 51 56 62 52 58 61 64 55 64 64 64

Chapter 3 67

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