1. The greenhouse effect is the capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating and warming the planet.
Without the thermal blanketing of the
natural greenhouse effect, Earth’s climate
would be about 33 degrees Celsius
(about 59 degrees Fahrenheit) cooler, too cold for most living organisms to survive.

2. As this schematic indicates, the greenhouse effect involves a
number of different responses to sunlight and the energy it represents.

3. Most of the sun’s energy reaches Earth in the form of visible light.
Electromagnetic Spectrum
Image: (SPECS, 1996)
Most of the sun’s energy reaches Earth in the form of visible light.
Light energy represents just one portion of the electromagnetic spectrum.

4. Atmospheric Reflection
Need to purchase or get alternative
When the visible light arriving from the sun interacts with our atmosphere,
a portion of this light energy is reflected back into space by the atmosphere.

5. The rest of the incoming solar radiation penetrates the atmosphere
and reaches the Earth’s surface.
At the surface one of two things occur:

6. Earth’s Albedo Effect (surface reflection)
Some of the light penetrating the atmosphere reflects off of the Earth’s surface and bounces back out into space.

7. Absorption and Conversion to Heat
Some of the light energy reaching the surface is absorbed by Earth’s surface.
In the process, visible light energy is transformed into
heat energy and certain characteristics are altered.

8. Electromagnetic Spectrum
Same as slide
Image: (SPECS, 1996)
As light is absorbed at the Earth’s surface, it can be re-radiated as heat energy.
This form of energy, also referred to as infrared,
has a longer wavelength than visible light.

9. Earth cannot travel back out through the atmosphere as easily.
Image: (Our changing climate, United States Global Change Research Program)
The longer wavelength of the heat radiated back from the surface of the
Earth cannot travel back out through the atmosphere as easily.
Some of this energy is trapped by the various gases in the atmosphere.
This is the basis of the greenhouse effect.

10. What gases
contribute to the
greenhouse effect
and where do they
come from?

11. Chlorinated Fluorocarbons (CFCs)
There are a great number of influential greenhouse gases in addition to water vapor. The most influential are:
Carbon Dioxide (CO2)
Methane (CH4)
Nitrous Oxide (N2O)
Chlorinated Fluorocarbons (CFCs)
Each has unique heat-trapping
properties as a greenhouse gas.

12. Sources of various greenhouse gases:
Natural Sources
Anthropogenic
Carbon Dioxide
* Cellular respiration and
decay
* Natural fires
* Volcanoes
* Warming oceans
* Combustion of fossil fuels
* Land use conversion
* Cement production
Methane
* Animal digestion
* Methane hydrates
* Rice paddies
* Livestock
* Landfills
Nitrous Oxide
* Temperate and tropical
soils
* Oceans
* Fertilizer
* Industrial processes
Chlorinated Fluorocarbons
* None
* Liquid coolants
* Foam production

13. The Summative Impact of Various Gases on the Greenhouse Effect
(given their unique characteristics)
Carbon Dioxide 62.9%
CFC’s 12.8%
Nitrous Oxide 6.2%
Methane 18.2%
(Working Group I, 2007)

14. What are “carbon sinks” and how do they influence the carbon cycle?

15. The oceans as a carbon sink
Our planet would be better named “Water” than “Earth,” since most of its surface is covered by ocean.
Earth’s oceans act as a huge carbon sink”holding immense amounts of dissolved CO2.
This huge carbon sink responds to global temperature changes.
As ocean waters cool, they absorb more CO2 from the atmosphere.
As ocean waters warm, they release more CO2 into the atmosphere.

16. Because photosynthesis captures carbon,
forests are
also a form
of carbon sink.
Buy photo

17. Geologically, huge amounts of carbon dioxide
can be captured in limestone. This is another important, though slow-to-respond, carbon sink.

18. Throughout our planet’s history, natural processes
have kept CO2 and global temperature in close correlation.

19. anthropogenic sources of carbon dioxide affected
How have more recent
anthropogenic sources of
carbon dioxide affected
the cycling of carbon dioxide?

20. Carbon dioxide is released into the atmosphere when things are burned.

21. Today’s industrial societies rely heavily
on the burning of different types of fuels.

23. anthropogenic source of CO2 changed the carbon cycle?
How have these recent
anthropogenic source of CO2
changed the carbon cycle?

24. Since our shift to an industrial way of life, carbon dioxide concentrations in the atmosphere have been rising.
This simple graph of the Mauna Loa Carbon Dioxide Record documents a 0.53%, or two parts per million per year, increase in atmospheric carbon dioxide since This gas alone is responsible for 63% of the warming attributable to all greenhouse gases according to NOAA's Earth System Research Lab.

26. Greenhouse Effect Video