Name_________________________________________________
Lecture Notes II: Climate and Climate Change
What causes Climate?
___________________: The average, year-after-year conditions of temperature, precipitation, winds and clouds in an area.
Factors Affecting Temperature
1.
2.
3.
4.
Latitude: Warmer near the ________________________because the sun’s rays are more direct
Altitude: Temperature ___________________ for every 1km increase in altitude.
Distance from large bodies of water: Oceans moderate temperatures on land because large bodies of water heat slower
and cool slower.
Ocean currents: Ocean currents can bring warm or cold air to land.
Factors Affecting Precipitation
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
_________________________________:
o Amount of water vapor in air mass influences rainfall & snowfall.
o the amount of water vapor in the air depends on where the wind came
from (wind from oceans carry more water!)
o Air masses can be warm, cool, dry or humid
Mountain Ranges: When wind hit a mountain it ______, cools, condenses into
vapor, forms clouds and releases precipitation.
The Seasons
SEASONS HAVE NOTHING TO DO WITH HOW FAR THE EARTH IS FROM THE SUN!
Earth is ______________________ from the sun during the summer in the
Northern Hemisphere.
 Tilted Axis
o Seasons are caused by the tilt of Earth’s axis as it travels
around the sun.
o The axis always points in the same direction so half the year
it is pointed toward the sun and the other half year it points away from the sun.
o Summer is warmer because of ____________ sun rays. Winter is colder because of indirect sun rays.
Climate Regions
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Scientists classify climates according to 2 major factors: ____________________ and _________________________
6 main climate regions: Tropical rainy, dry, temperate marine, temperate continental, polar, and highlands
Climate Regions:
o Tropics:
 Tropic wet: _________________________
 Year round heat and heavy rain
 Lush green vegetation
 Tropic wet and dry: ____________________ (tropical grasslands)
 Distinct dry and rainy seasons
 Only a few trees here that can survive dry season
o Dry Climates
 ____________________receive less than 25 cm. of rain per year
 They can be hot or cold!
 Only specialized plants (cactus) can survive the dryness and temperature extremes.
o
Temperate Marine Climates
 Found along the coasts of continents
 Oceans moderate the temperature
o
o
o
 Humid
 Have mild winters
Temperate Continental Climates
 Not influenced by oceans
 Have extremes of temperature
Polar Climates
 Coldest climate region
 _____________: Climate region with avg. temperatures at or below freezing, and covered with ice
and snow.
 Tundra: climate region with short cool summers and bitterly cold winters (more life than in icecap)
 Permafrost: ______________________________________________
____________________________:
 Places with high altitudes
 Temperature falls with increasing altitude so these regions are colder than those surrounding them.
 Precipitation increases (air masses carrying moisture over highlands)
Studying Climate Change
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
_______________________: pollen (from bottom of lakes and inside earth) give us information
about ancient plants and therefore ancient climates.
Tree rings: Trees grow a new layer of wood each summer and scientists study the pattern of rings
and determine if previous years were warm, cool, wet or dry.
o Cool climates: thickness of tree ring depends on length of warm growing season.
o Dry climates: Thickness depends on amount of _________________
Causes of Major Climate Change
1. ___________________________: Angle of Earth’s tilt and shape of orbit change slightly over time (may cause ice ages)
2. Solar Energy: Sunspots are dark, ___________________ regions on the sun’s surface, and they increase/decrease in 11year cycles. When there are more sunspots the sun produces more energy (increase Earth’s temp.)
3. Volcanic Activity: Release of _____________________ block solar radiation and cool the planet.
4. Movement of Continents: These changes affect global patterns of winds and ocean currents, and therefore the climate.
Short Term Climate Change
 Changes in ocean currents and wind can greatly affect climate.
 _______________: Warm water event when unusual patterns of winds form over the
western Pacific. Occurs every 2-7 years, changes weather patterns and can cause heavy
rains or droughts for South America.
 La Nina: ____________________ event in Eastern Pacific that changes climate and
brings colder winters, greater precipitation to USA, and more hurricanes.
Global Warming
 Most changes in climate occur ________________________
 Recently, human activities have caused climate change.
 Human activities have added _______________________________ to the environment, trapping heat and making
Earth warmer.
 More carbon dioxide emissions (cars, planes, industries) causes more heat to be trapped.
 ________________layer is being destroyed by human activity (CFCs) and letting in harmful UV rays to Earth.