1. Land, Water, and Air Resources Chapter 4 4.5 Global Changes in the Atmosphere

2. The Source of Ozone The ozone layer is a natural layer found in the upper atmosphere.

3. The Source of Ozone The ozone layer is a natural layer found in the upper atmosphere. There is only a little ozone in the upper atmosphere.

4. The Source of Ozone The ozone layer is a natural layer found in the upper atmosphere. There is only a little ozone in the upper atmosphere. It does a very important job.

5. The Source of Ozone The ozone layer is a natural layer found in the upper atmosphere. There is only a little ozone in the upper atmosphere. It does a very important job. Ozone reflects ultraviolet radiation (source of sunburn) and protects the Earth’ surface’ surface.

6. Ozone Cycle page 147 Before sun energy reaches the surface of Earth. Most is bounced off the upper atmosphere.

7. Ozone Hole In 1970 Scientists observed that the ozone layer over Antarctica was getting thinner.

8. Ozone Hole In 1970 Scientists observed that the ozone layer over Antarctica was getting thinner. Years of research determined that a human cause came from chemicals called CFC’s

9. Ozone Hole In 1970 Scientists observed that the ozone layer over Antarctica was getting thinner. Years of research determined that a human cause came from chemicals called CFC’s CFC’s react with ozone molecules and stop the ozone from blocking ultraviolet radiation.

10. Ozone Hole CFC’s came from spray cans like paint and hairspray and also from air conditioners and refrigerators.

11. Ozone Hole CFC’s are very stable and they will remain in the upper atmosphere for many years.

12. Ozone Hole In an historic agreement many nations banned production of CFC’s.

13. Ozone Hole Scientists predict that the ozone layer can recover but it will take many years.

14. Greenhouse Effect Gases in the atmosphere carbon dioxide CO2 water vapor H20 act like windows that let in sun energy.

15. Greenhouse Effect The energy is trapped near the Earth’s surface.

16. Greenhouse Effect Without this greenhouse effect the Earth would be much cooler.

17. Greenhouse Effect Human activities that increase carbon dioxide, (CO2) emissions can increase the greenhouse effect and raise the temperature of the atmosphere.

19. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex

20. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are:

21. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are: Ocean currents,

22. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are: Ocean currents, Cloud cover,

23. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are: Ocean currents, Cloud cover, Forest cover,

24. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are: Ocean currents, Cloud cover, Forest cover. Volcanoes,

25. Difficulties of Predicting Climate Change The Earth systems that determine climate are very complex Some of the many variables that impact climate are: Ocean currents, Cloud cover, Forest cover. Volcanoes, Emissions of greenhouse gases

26. Difficulties of Predicting Climate Change The study of climate systems is very young less than a century old.

27. Difficulties of Predicting Climate Change The study of climate systems is very young less than a century old. Computer models are used to try and predict atmospheric changes.

28. Difficulties of Predicting Climate Change The study of climate systems is very young less than a century old. Computer models are used to try and predict atmospheric changes. Even with the most sophisticated computer models it will take many years to tell if the predictions are accurate.

30. The end