Download Earth*s Climate System

8.3 & 8.4 EARTH’S
CLIMATE SYSTEM
THE SUN POWERSEARTH’S CLIMATE
• Climate System: complex set of components
that interact with each other to produce
Earth’s climate.
• Includes sun, air, land, liquid water and ice
and living things
BALANCE OF ENERGY ON EARTH
• Almost all energy on Earth comes from the Sun
• The sun emits radiation:
– ultraviolet (short wavelength, high energy)
– Visible light
– infrared (long wavelength, low energy)
How does Radiation Interact?
• Can be absorbed: causing particles to gain
energy
• Can be transmitted through the particle
• Can be reflected off the particle
What Happens to the Sun’s energy?
• 30% of solar radiation is reflected back into
space by the atmosphere, clouds, and Earth’s
surface
• 70% is absorbed by the atmosphere, clouds,
and Earth’s surface
• See page 326 in text
What happens to the absorbed energy?
• < 1% absorbed by plants to power photosynthesis
• Absorbed by rocks and water to heat up earth
• As Earth’s temperature increases, air above is
heated
Balancing Earth’s Climate
• Earth absorbs suns energy and gains thermal
energy
• Earth emits lower-energy infrared radiation back
out
• Energy absorbed = energy radiated back
19% + 51% = 64% (indirectly) + 6% (directly)
Helps keep Earth’s global temperature fairly constant
Answer these in your book…
1 If the Sun shines constantly on the Earth, why
doesn’t it keep warming up?
2 What would happen to the Earth’s
temperature if
– The amount of energy from the Sun stayed the
same but the amount radiated back from the
Earth increased?
– The amount of energy from the Sun stayed the
same but the amount radiated back decreased?
Latitude Affects Climate Too!
• Climates are warmest near the equator
because the sun shines directly overhead
• Closer to the poles, the sun hits surface at an
angle and is weaker
Extra Facts
• Mercury has no atmosphere and is 450°C
during the day and -170°C at night
• Venus’ atmosphere is 100 times more dense
than Earth’s causing its surface temperature to
be 700°C.
• Mars has an atmosphere 100 times less dense
than Earth’s, causing its surface to be
-63°C
GOD made earth so perfect 
COMPONENTS OF EARTH’S CLIMATE
• There are 4 main components to Earth’s
climate system
1 THE ATMOSPHERE
2 THE HYDROSPHERE
3 THE LITHOSPHERE
4 LIVING THINGS
1 THE ATMOSPHERE
• mixture of gases 78% nitrogen 21% oxygen and 1% other
(ozone, CO2, hydrogen etc.)
• Allows solar radiation to strike the earth’s surface
• Can also absorb some thermal energy from Earth and reflect it
back to earth before it can go out into space. This is called the
greenhouse effect.
OZONE
• The ozone protects living things from the harmful effects of UV
rays
• In 1970 scientists noticed the ozone layer over Antartica was
thinning
• In the 1990’s a similar ozone “hole” began to form over the Arctic
• Caused by human made CFC’s (chlorofluorocarbons)
• In 1987 the governments around the world signed an agreement
in Montreal called the Montreal Protocol on Substances that
deplete the ozone layer
• The ozone layer is beginning to recover and will take at least 50
more years to return to its original thickness
2 THE HYDROSPHERE
The hydrosphere is made up of all of the water on the earth in all
of it’s different forms.
The Hydrosphere…cont’d
• Large bodies of water absorb and store more thermal
energy than land and therefore warms and cools more
slowly
• Land near bodies of water take longer to heat up during
spring and longer to cool down during fall
• Regions down wind from bodies of water tend to get more
snowfall. Air passing over absorbs moisture and then falls
as snow as it reaches the colder air inland
The Hydrosphere…cont’d
• Ocean currents help distribute thermal energy
concentrated at the equator towards the poles.
• great ocean conveyor: an overall circulatory pattern
The Great
Ocean
Conveyor
The Hydrosphere cont’d
• 2% of all Earth’s water is frozen
• Most of this ice is located at the poles
• Ice/snow reflect more thermal energy, adding to the reason
why these areas are so cold
The Lithosphere
• Is the Earth’s crust—it includes all rock, soil and minerals
on land and under the oceans
• It absorbs solar energy and emits it back as lower energy
The Lithosphere—LAND FORMATIONS
& CLIMATE ZONES
• Mountains and other land formations affect how air moves
over an area
• As clouds blow over mountains they lose their moisture as
rainfall on the windward side
• The leeward side receive little rain (rain shadow effect)
The Lithosphere—ALTITUDE &
CLIMATE
• higher altitudes have lower atmospheric pressure because
there is less air pushing down
• Therefore, air from lower altitudes rises to high altitudes,
expands and cools down
• mountain tops = cooler
Living Things
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•
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All organisms are part of the climate system
Plants and animals exchange gases in the atmosphere
Photosynthesis releases O2
Cellular respiration releases CO2
Animals release methane during digestion as do bacteria
The quantities of these gases change which affects climate by
their ability to absorb radiation
Homework:
Pg 329 2,6
Pg 335 1, 4, 5, 6