1. 8.3 & 8.4 EARTH’S CLIMATE SYSTEM

2. 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

3. 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)

4. How does Radiation Interact?
Can be absorbed: causing particles to gain energy
Can be transmitted through the particle
Can be reflected off the particle

5. 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

7. 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

8. 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

9. Answer these in your book…
If the Sun shines constantly on the Earth, why
doesn’t it keep warming up?
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?

10. 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

12. GOD made earth so perfect 
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 

13. 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

14. 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.

15. 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

17. 2 THE HYDROSPHERE
The hydrosphere is made up of all of the water on the earth in all of it’s different forms.

18. 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

19. 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

20. 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

21. 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

22. 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)

23. 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

24. Living Things 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

25. Homework:
Pg ,6
Pg 335 1, 4, 5, 6