1. The Atmosphere

2. Atmosphere: layers of Gases  The earth is wrapped in layers of mixed gases  These gases reach 100km above the earth’s surface  The air we breath is a mixture of gases (78% nitrogen, 21% Oxygen, remaining 1% is a combination of argon, carbon dioxide and traces of helium, hydrogen and ozone)

3. Atmosphere: a big blanket around Earth  The atmosphere reflects, absorbs, radiates and transmits some of the sun’s energy  Once the energy of the sun reaches the earths surface, the atmosphere traps much of it, warming the earth

4. Atmosphere: Protector  Some of the sun’s energy is dangerous and can cause sunburns and skin cancer  Ozone (O3) in the atmosphere prevents most of the harmful energy to reach earth  In the 1970’s and 1990’s scientists found that the ozone layer was thinning over Antarctica and the Arctic  This was cause by the human use of CFC’s

5. Is the Ozone layer recovering?  Research the use of CFC’s and the Montreal Protocol  Create a brochure of your findings

6. Ozone in the Troposphere  Ozone has a toxic effect in the lower troposphere (where we live)  Ozone is produced when UV radiation from the sun combine with the exhaust from cars  Ozone does not move from the troposphere into the stratosphere, and causes damage to humans, plants, animals and buildings  How does the “Drive Clean” program by the Ontario Government help in preventing the production of ozone? www.ene.gov.on.ca/en/air/driveclean/