1. So is the burning of fossil fuels (coal & oil) causing changes in global climate? If so, how?

2. This is a natural process in which atmospheric gases trap radiated heat

3. Remember, without this Earth would have Moon-like temperatures So what’s the problem? The Greenhouse Effect

4. If one blanket keeps you warm at night, what would be the effect of two blankets? You’d be too warm!

5. What gas is the main contributor to the Greenhouse Effect? CO 2  the most famous greenhouse gas?No! CH 4 (methane)  another gas in the news a lot?No! N 2 O (nitrous oxide)  a gas in the news a bit?No! Some mysterious little known new gas? Water vapor accounts for about 95% of Greenhouse Effect So if it is a natural phenomena, mostly caused by water vapour, what’s the big deal?

6. Human activity is increasing the amount of the other greenhouse gases in the atmosphere

7. 1. Deforestation means less photosynthesis to soak up CO 2. as the forests are burned N 2 O is released

8. releases CO 2 and N 2 O 2. Burning of fossil fuels

9. However neither releases a lot of CH 4 (methane) So where does the CH 4 come from? Ruminants such as cows and sheep breakdown cellulose this produces waste methane 3. Methane from cows with the help of bacteria in their rumen

10. But are there really more cows in North America than we used to have in our buffalo herds? used to be 60 million buffalo now about 120 million cows so has methane production only gone up by 2X?

11. No, methane production is way up!Why? Buffalo eat grass at a slow and steady rate and grow slowly. Cows eat grain, silage and hay at high rates to grow fast. So one cow actually makes 2x or 3x as much methane as one buffalo. And remember, there are more cows.

12. 4. Other chemicals a. fluorocarbons No longer used in aerosol cans where CO 2 has replaced them Now used mostly as coolants in air conditioners And as cleaners of circuit boards for computers

13. b. sulphur hexfluoride [SF 6 ] production of magnesium and magnesium alloys the cleaning of aluminum

14. a. transportation fuels b. waste disposal/processing c. power stations d. industrial processes e. residential/commercial use f. agricultural g. obtaining/processing fossil fuel What human activities actually are causing the most problems? Rank these sources of Greenhouse Gases (in pencil) h. Land use and biomass burning

23. Not all greenhouse gases are equal: carbon dioxide CO 2  1 GWP methane CH 4  24 GWP nitrous oxide N 2 O  300 GWP fluorocarbons XFC  2000 GWP sulphur hexafluoride SF 6  24000 GWP GWP is global warming potential per molecule a big GWP is bad!

24. So if CO 2 has such a low GWP why are we so worried about that one gas? Even though CO 2 has a low GWP it is still the major greenhouse gas after water vapour

25. What are the effects of all these excess Greenhouse Gases? What can we do about it all?