1. Greenhouse Effect Mechanisms Affecting the Greenhouse Evidence for Climate Change

5. 1. Radiation from Sun enters atmosphere a. Reflection (clouds, ice, water) b. Absorption by Surface 2. Earth’s surface creates infrared radiation a. Greenhouse gases trap infrared radiation b. CO2, H20, CH4

7. 1. Increased Solar Reflection a. Volcanic ash, impact ash, glaciers b. Plate tectonics /ocean currents/ice caps 2. Less solar radiation from Sun (orbit/tilt) 3. Less greenhouse gases (cycles)

9. 1. More greenhouse gases a. Changes in cycles that recycle gases b. Burning of fossil fuels c. Volcanic gases 2. More solar radiation a. Changes in Earth’s tilt and orbit b. Positive feedback loops

12. Evidence for Climate Change PASTPRESENT North America Ice Age Glacial material & landforms, lakes, sea levels, extinctions Retreating Glaciers (melting) North pole ice sheet shrinking Eocene Thermal Maximum Sea levels, ocean core samples, extinctions Changing migrations Species moving northward Average global temps Ocean temps Sea Levels