1. Dark Skies: Volcanic Contribution to Climate Change

2. Volcanoes

3. Mount St. Helens, May 1980 http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/

4. Mount St. Helens, May 1980 http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/

5. Compare and Contrast Images Image AImage B

6. Layer of fine droplets following the Pinatubo eruption Pristine Atmosphere

7. Volcanic Contribution to Climate Change Step 1 Ash and gas enter the atmosphere

8. Volcanic Contribution to Climate Change Step 2 Ash and gas spread throughout the atmosphere. Eventually, the Earth is wrapped in a layer of ash and gas. Ash and gas plume from Mt. Etna, in northeastern Sicily.

9. Volcanic Contribution to Climate Change Step 3 Ash and gas block energy from the Sun. Earth's temperature drops.

10. Volcanic Contribution to Climate Change Step 4 Heat radiating off the surface of Earth becomes trapped in the layer formed by the eruption. Trapped heat changes global climate patterns.

12. Krakatau Sunsets 1883-85 Krakatau 1883 El Chichon 1982