1. The Greenhouse Effect

2. Some atmospheric basics The greenhouse effect Radiant energy that is absorbed heats Earth and eventually is reradiated skyward – Radiation is in the form of longwave infrared radiation – Atmospheric gases, primarily H 2 O and CO 2, are more efficient absorbers of longwave radiation – This selective absorption, called the greenhouse effect, results in warming of the atmosphere

4. The greenhouse effect

5. IPCC 2007

6. Why Focus on CO2? Only 390 ppm (0.039%) of the atmosphere The total number of CO2 molecules above our heads in the atmosphere is more important than their percentage in the atmosphere

7. What are the greenhouse gases? (excluding H 2 O) Carbon Dioxide:49% Methane:18% “CFC’s from coolants, solvents, etc ”:14% Nitrous Oxides: 6% Others:13%

8. Most outgoing Earth radiation is intercepted and absorbed by greenhouse gases like water vapor, methane, and carbon dioxide.