1. GREENHOUSE EFFECT

2. GREENHOUSE EFFECT
Earth is unique in the solar system in that it is the only planet that supports life as we know it.
Several factors account for this:
Position near the sun: not too close, not too far
Abundance of water
Right mixture of chemical compounds needed for life
Right types of gasses in the right combination making up our atmosphere

3. Right types of gasses in the right combination make up our atmosphere
GREENHOUSE EFFECT
Let’s look at the last factor…
Right types of gasses in the right combination make up our atmosphere
Why is this so important?

4. GREENHOUSE EFFECT
The earth’s atmosphere is a protective blanket which surrounds our planet.
It allows the right amounts of sun’s energy in and out, creating a climate that is supportive of life

5. SUN’S ENERGY
The sun’s energy reaches the earth in the form of electromagnetic radiation.
Electromagnetic radiation includes visible light, infrared (heat), ultraviolet wave lengths and others forms of energy.

6. SOLAR ENERGY
Two things can happen to solar radiation as it approaches earth’s atmosphere
Solar radiation can be reflected back into space
Solar radiation can be absorbed by clouds, gases like ozone or earth’s surface - or scattered by the atmosphere.

7. SOLAR RADIATION
Some of the solar radiation is reradiated or emitted by the earth in the form of long-wave radiation
This long-wave radiation is absorbed by certain gasses in the earth’s atmosphere.
These gasses are called “greenhouse gasses”

8. GREENHOUSE GASSES Naturally Occurring Water Vapor Methane
Nitrous Oxide
Carbon Dioxide
Influenced by humans
CFC’s
Ozone (?)

10. The level of greenhouse gases can be affected by man-made and natural processes

11. MAN-MADE PROCESSES Burning fossil fuels→CO2 and NOx
Removing vegetation (deforestation)→CO2
Using aerosols→CFC
Polluting of oceans and waterways →methane

12. NATURAL PROCESSES Volcanic Eruptions Carbon Cycle Water Cycle
Decay→methane
Oceans and bacteria in soil→nitrous oxide

13. MAN-MADE CONTRIBUTIONS
Man-made contributions to greenhouse gases are potentially devastating
The rise in greenhouse gases, especially carbon dioxide, are being attributed to a general rise in earth’s temperature.

14. These two graphs show the relationship between carbon dioxide concentrations in ice core data/Mauna Loa data and global average temperatures.
There seems to be a direct correlation between the two

15. So what are the consequences of an overall rising temperature on Earth?

16. CONSEQUENCES
Several theories exist as to what may become of our earth if temperature continue to rise
Rise in sea level due to melting glaciers
Balance of salt water in oceans will change, possibly affecting wildlife
More tropical, dry weather in parts of world
Increase in severe weather

17. rst.gsfc.nasa.gov/Sect16/Sect16_2.html

18. VIDEO CITATIONS
Greatest Discoveries with Bill Nye: Earth Science. Discovery Channel School unitedstreaming. 1 July 2007 <