1. Climate Change

2. Is Climate Change a new phenomenon?  NO!  It is natural for Earth’s climate to change.  There are mass warmings and mass coolings.  Periods of glaciation occurred because the average temperature dropped by as little as 4˚C  More recently, historical climiatologists have suggested that an important event in Canada’s history was caused by global warming. Around the year 1000, the Vikings built at least one settlement in northern Newfoundland. Scientists think that they were able to do so because of warm temperatures.

3. Greenhouse effect Think of being in a car in the winter:  On a sunny day, in the winter one can sit in a car with the engine off and still be warm, despite the cool air outside.  The same thing happens with the Earth, except gasses work as the insulator.

4. Earth’s atmosphere http://lpc1.clpccd.cc.ca.us/lpc/harpell/images/Earth_Moon_atmosphere.jpg

5. The Greenhouse Effect http://apps1.eere.energy.gov/state_energy_program/update/images/06-07_greenhouse_effect.jpg

6. Greenhouse Gasses  Without greenhouse gasses, the Earth’s temperature would drop by more than 33˚C.  On the other hand, if the amount of greenhouse gasses is increased, less heat can escape into space and the temperature of the Earth’s atmosphere gets higher. This is called global warming.  The main greenhouse gasses are: carbon dioxide, methane, nitrous oxide, halocarbons, ozone, and water vapour.

7. Global Warming

8.  As said, Global Warming is a natural phenomenon: What isn’t natural is an increase in greenhouse gasses as a result of human activities. Human activities that enhance global warming:  Burning of fossil fuels  Overpopulation  Farming