1. Feedback Loops

2. FEEDBACK LOOPS Change induces change What happens when you’re hot? What happens when you’re cold? These are examples of negative feedback The change counteracts the situation

3. Positive feedback Loops Change induces change As long as there are more human births than deaths, population will continue to increase. Snowball Effect

4. Feedback Loops in Context Global warming hypothesizes that the average temperature of Earth is increasing. During analysis, scientists have identified possible positive and negative feedback loops to explain atmospheric climate change. http://science.howstuffworks.com/global-warming.htm

5. Radiation and Reflection

6. The Greenhouse Effect explained http://www.youtube.com/watch?v=LFNKfWy GxHw&feature=related http://www.youtube.com/watch?v=LFNKfWy GxHw&feature=related Cartoon emphasizing the percentages of radiation and re-radiation. http://www.youtube.com/watch?v=GBQ8- zEcE9w&feature=related http://www.youtube.com/watch?v=GBQ8- zEcE9w&feature=related Global warming animation made by an ES kid

7. Global warming is a significant increase in the Earth's climatic temperature over a relatively short period of time, mainly as a result of the activities of humans. In specific terms, an increase of 1 or more Celsius degrees in a period of 100 – 200 years would be considered global warming. Over the course of a single century, an increase of even 0.4 degrees Celsius would be significant.

8. Positive or Negative? The warming of the oceans causes dissolved CO 2 to bubble out into the atmosphere. This atmospheric CO 2 helps to trap heat near the earth. This trapped heat continues to warm the ocean.

9. Positive or Negative? Warmer water temperatures cause greater water evaporation, which increases the formations of clouds. A lot of water vapor in the air also traps heat inside the atmosphere.

10. Positive or Negative? The increased cloud cover from example 2 might also act to reflect sunlight back into space, preventing it from entering our atmosphere. This might cool the earth.

11. Positive or Negative? Sunlight striking the earth is absorbed by dark colors and reflected by light colors. The polar ice caps act like huge mirrors, reflecting sunlight back into space. Warmer water temperatures are melting these ice caps and decreasing these big “mirrors,” leaving dark water behind.

12. Positive or Negative? Warmer temperatures cause greater water evaporation, which falls to earth as precipitation. Therefore global warming may cause increased snow fall in the polar regions, leading to increased ice formation.

13. How did you do? 1. Positive 2. Positive 3. Negative 4. Positive 5. Negative

14. Contemplate this… What would Earth look like if there weren't any greenhouse effect at all? It would probably look a lot like Mars.Mars Mars doesn't have a thick enough atmosphere to reflect enough heat back to the planet, so it gets very cold there.

15. Hmmmmm…. Some scientists have suggested that we could terraform the surface of Mars by sending "factories" that would spew water vapor and carbon dioxide into the air. terraform the surface of Mars If enough material could be generated, the atmosphere might start to thicken enough to retain more heat and allow plants to live on the surface.

16. Just like early Earth… Once plants spread across Mars, they would start producing oxygen. After a few hundred or thousand years, Mars might actually have an environment that humans could simply walk around in -- all thanks to the greenhouse effect.