Childrens Illustrated Encyclopedia

125

WORLD CLIMATES

The different climates of the world
run in broad zones around Earth

on either side of the equator. They
range from hot and rainy climates

at the equator to cold climates at the
poles. There are five main climatic

zones, each of which is shown on
this map by a different color.

SOME PARTS OF THE WORLD, such as the tropical rain forests of South

America, are hot and damp throughout the year. Other regions, such as the

Arctic, have long, freezing winters. Conditions such as these are known as

the climate of an area. Climate is not the same as weather. Weather can

change within minutes; climate describes a region’s weather conditions

over a long period of time. Every region has its own climate. This depends

on how near it is to the equator, which governs how much heat it gets from

the sun. Landscape also influences climate; high mountain regions, such as

the Himalayas, are cooler than nearby low-lying places. The ocean can

prevent a coastal region from getting very hot or very cold, while the weather

in the center of a continent is more extreme. The climate of a region affects

landscape and life—clothing, crops, and housing. But climate can change.

Today climatologists, people

who study climates,

believe that the

world’s climate

is gradually

warming up.

SUN AND CLIMATE

The sun’s rays warm the equator

directly from above, making the

tropics hot. Away from the

equator, the sun’s rays are less

direct, making climates cooler.

SAHARA DESERT

The Tuareg nomads are one

of the few peoples that live

in the punishing climate of

the Sahara Desert, coping

with the searing heat of the

day and the freezing

temperatures at night.

TEMPERATE CLIMATE

Warm summers and cool

winters feature in warm

temperate climates. Rain may

fall all year, or the summer

can be dry and sunny, as in

Mediterranean regions.

Away from the

equator, the sun’s

rays are spread

over a wide area.

In temperate

climates, trees

shed their leaves

in the winter.

COOL FOREST CLIMATE

Summers are cool and short,

and winters are long and cold.

Pines and other conifers grow

in huge forests that cover much

of the land.

TROPICAL CLIMATE

It is hot all year round in tropical

regions, and torrents of rain

usually fall every afternoon. Rain

forest covers much of the land. In

regions where wet and dry seasons

occur, tropical grasslands grow.

DESERT CLIMATE

In the dry, barren deserts,

cold, clear nights usually

follow burning-hot days.

However, high mountain

deserts may have cold,

dry winters.

THE FREEZING ANTARCTIC

Only hardy creatures, such as

penguins, can survive amid the

ice and snow of the Antarctic.

POLAR CLIMATE

It is cold all year, and ice and

snow always cover the ground.

No crops grow, and the few

people who live there hunt

animals for food.

The Sahara

is the largest

desert in the

world.

Climates

CLIMATIC CHANGES

Great climatic changes,

such as ice ages, come and

go during thousands of

years. But severe changes

in climate can also occur

suddenly or within a few

years. Dust from volcanic

eruptions can obscure the

sun, making a climate

cooler. Changes in winds

can cause rainfall to shift

from a region, bringing

drought. Human activities,

such as pollution, also

affect climate greatly.

GREENHOUSE EFFECT

The atmosphere works like

a greenhouse, trapping the

sun’s heat and warming Earth.

Pollution in the air traps more

heat, making Earth warmer.

Unless pollution is reduced,

Earth’s climate could be changed

Escaping heat

Trapped

heat

Sun’s

rays

The treeless

landscape of

the polar regions

is called

the tundra.

Find out more

Atmosphere

Earth

Glaciers and ice caps

Weather

Wind

The cool forest climate

exists only in the northern

half of the world.