1

Greenhouse Gases and Energy Budget

LP 3

2

What are the greenhouse

gases?

Where do they come from?

How do they work?

3

What is the greenhouse effect?

4

Composition of the Earth’s Atmosphere

• Nitrogen N2 = 78 %

• Oxygen O2 = 21 %• Argon Ar = 0.9 %• Other = <0.1%

– Carbon Dioxide CO2

– Methane CH4

– Nitrous Oxide NO2

– Ozone O3

– Hydrogen

5

Greenhouse GasesCarbon Dioxide

Water

Methane

Nitrous Oxide

Ozone

6

Resonance Models

7

The “Goldilocks” Principle

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

CO2 H2O

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)

9

10

Frequency