Chapter 21 Reading Guide
Climate and Climate Change
21.1 What is Climate?
List climate characteristics and control factors in the appropriate box.
Climate Characteristics
Temperature, precipitation, days/hours of
sunlight; wind direction, speed and
steadiness; frequency of severe weather
Climate Controls
Latitude; elevation, nearby water, ocean
currents; topography; prevailing winds;
vegetation
1. Explain the differences between daily and annual temperature ranges.
Daily: ranges reflect the difference between high and low temps on a given day.
Annual: contrast high and low monthly temps in a year.
2. Choose two climate control factors and explain their impact on both temperature and
precipitation.
Higher elevations lead to colder temperatures and less precipitation. Ocean currents cool
or warm nearby coasts depending on their temperatures. Can also cause fog.
3. Which climate control factor do you think has the most impact on Seattle,
Washington? How about Denver, Colorado? Explain?
In Seattle, nearby water probably has the most impact, creating a mild climate and regular
precipitation. In Denver, elevation and topography might have strong impacts with the
first causing cooler temperatures and the second moderating those cool temperatures and
minimizing precipitation.
21.2: Climate Zones
Complete the organizer with details about the likely climate features and locations of
each listed zone. Also give the names of any subclimates in each zone.
1. Polar
a) Subclimates: tundra, ice caps
b) Location: at poles
c) Features: little precipitation,
minimal or no vegetation
3. Humid tropical
a) Subclimates: tropical, wet; tropical
wet/dry.
b) Location: close to the Equator and
in the Intertropical Convergence
Zone (ITCZ)
c) Features: Hot and very rainy most
of the year; hot all year with wet
and dry seasons.
2. Dry
a) Subclimates: Desert; semiarid
b) Locations: leeward side of
mountains, horse latitudes
c) Features: high temperatures with
cold nights, evaporation exceeds
precipitation, plant and animal life
adapted to dryness
4. Moist mid-latitude with mild winters
a) Subclimates: humid subtropical;
marine west coast; Mediterranean
b) Location: Southeastern US,
Western Canada, Pacific Northwest
c) Features: hot, humid summers and
mild winters; mild an rainy all year;
hot, dry summers and mild, rainy
winters
Or
Moist Mid-latitude, with Severe Winters
a) Subclimates: Humid, continental;
subarctic
b) Location: Interiors of Continents,
Northeastern US east of the Great
Plains; closer to the Poles
c) Features: Warm summers and cold,
snowy winters; short summers and
long cold, snowy winters
Describe the Highland climate zone and explain how it is different from the other main
zones.
Highland climate zone occurs in mountainous areas and its features vary with the
influence of latitude and elevation. It differs from the other zones by incorporating many
mini zones within the same general location.
21.3 Climate Change
Complete the organizer by writing a cause and effect sentence explaining each theory of
global climate change.
1. Earth’s Motion
2. Plate Tectonics
3. Sunspots
4. Volcanoes
5. Human Activities
Changes in the shape of the Earth’s orbit,
the tilt of its axis, and the axis of its
rotation affect the intensity of the seasons.
Changes in continent position affect wind
patterns, ocean currents, and solar radiation
absorption, creating global cooling or
warming.
Changes in sunspots on the Sun’s surface
alter the amount of solar energy reaching
the Earth.
Individual eruptions can cool temperatures
by blocking solar energy with their debris.
But repeated or extensive eruptions can
warm temperatures by raising atmospheric
carbon dioxide.
Deforestation and fossil fuel burning
increase carbon dioxide levels and warm
temperatures.
List and describe a method that scientists use to study climate changes.
Changes in sea-floor sediments indicate changes in water temperature and degree of
glaciation over time. Changes in the oxygen features of glacial ice indicate variations in
temperature during formation. Number of growth rings indicates age of trees and likely
climate conditions each year.