Ch.6 Climate
Sect. 1 “What is Climate?”
Climate – the pattern of weather that occurs in an area over many
years.
 Determines types of plants or animals that can survive, and
influences how people live.
 5 elements averaged to determine climate:
1. temperature
2. precipitation
3. days of sunshine
4. humidity
5. air pressure
Factors that affect Climate:
1. Latitude – distance N or S of the equator (lay down)
a. Tropics – (23˚N & 23˚S) – sun shines almost directly
overhead, keeping temperatures high – hot.
b. Polar zones – (66.5˚N & 66.5˚S latitude to the poles) –
sun shines at a low angle keeping temperature low – cold.
c. Temperate zones – (between the tropics & the polar
zones – moderate, mild temperatures.
2. Large bodies of water
3. Ocean currents can bring cool or warm temp. and moisture to
coastal areas.
4. Mountains
 At the same latitude, the climate on a mountain is
colder than the climate at sea level.
 Mountains cause air to rise, cool, & condense, creating
a wetter climate on the windward side of the mountain
& a much drier climate on the leeward side.
5. Cities – have higher temperatures than surrounding areas
because of the asphalt & concrete absorbing radiation.
Sect. 2: Climate Types
Climatologist – studies climate types.
W. Koppen developed a system of classification for climate types
based on:
 Temperature
 Precipitation
 Plant types
6 types of climate:
1. tropical
2. mild
3. dry
4. continental
5. polar
6. high elevation
Adaptation – any structure or behavior that helps an organism
survive in its environment.
1. Structural adaptation – body structures that help
organisms survive in certain climates.
Ex: fur of mammals, needles of a cactus, blubber of a
whale, cactus’s thick, fleshy stem helps it hold water.
2. Behavioral adaptation
Ex: hibernation, migration
Ex: estivation – period of inactivity through warm
periods.
Sect. 3: Climatic Changes
Seasons – short periods of climatic change caused by changes in
the amount of solar radiation an area receives.
1. As Earth revolves around the Sun, different areas of Earth
are tilted toward the Sun.
2. The tropics don’t experience much seasonal temp. change.
3. High latitudes near the poles experience great seasonal temp.
change.
El Niño – an occasional climatic event in which strong Pacific winds
weaken and sometimes reverse.
Effects of El Niño:
1. Ocean temp. near Peru heat up.
2. The position & strength of 1 of the jet streams may be
altered, changing wind and precipitation patterns around
the world.
3. Africa & Australia may experience drought.
La Niña – The winds blowing across the Pacific are stronger than
normal.
Causes of Climatic Changes can occur over short or long periods
of time.
1. volcanic eruptions
2. meteorite collisions
3. pollution
4. variations in solar radiation, possibly related to the
presence of sunspots
5. Earth’s movements in space can change the amount of
solar energy reaching it.
a. Earth’s tilt changes about every 41,000 yrs.
b. Earth’s axis wobbles in space.
c. The shape of Earth’s orbit changes over a 100,000yr. cycle.
6. The movement of Earth’s crustal plates affects the
transfer of heat on Earth.
Climatic Changes Today
1. Global Warming – Earth’s average global surface temp. is rising,
possibly due to the increase in greenhouse gases in our
atmosphere.
2. Greenhouse effect – a natural heating process that occurs
when certain gases such as carbon dioxide, methane, & water
vapor in Earth’s atmosphere trap heat.
3. Human activities affect the air.
a. burning fossil fuels – increases the amount of
carbon dioxide.
b. Deforestation – results in fewer trees to absorb
carbon dioxide.
c. Individuals can help reduce the amount of carbon
dioxide in the atmosphere by:
 Plant more trees
 Electric cars
 Reduce use of fossil fuels
 Recycle
 Reduce use of water and electricity
 Walk, ride bikes, carpool
 Burn in a fireplace rather than turning on
heater.