1. Greenhouse Gases and Energy Budget LP 3 1

2. What are the greenhouse gases? Where do they come from? How do they work? 2

3. What is the greenhouse effect? 3

4. Composition of the Earth’s Atmosphere Nitrogen N 2 = 78 % Oxygen O 2 = 21 % Argon Ar = 0.9 % Other = <0.1% – Carbon Dioxide CO 2 – Methane CH 4 – Nitrous Oxide NO 2 – Ozone O 3 – Hydrogen 4

5. Greenhouse Gases 5 Carbon Dioxide Water Methane Nitrous Oxide Ozone

6. Resonance Models 6

7. The “Goldilocks” Principle 7 Mars is too cold, Venus is too hot, but the Earth is just right!

8. What if Earth did not have greenhouse gases? Main greenhouse gases CO 2 H 2 O Temperature without greenhouse gases -5 °C (23 °F) Actual Average Temperature 15 °C (59 °F) Temperature change because of greenhouse gases 20 °C (36 °F) 8

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10. Frequency 10