2. Climatic Changes

3. During an average human lifetime, Climates do not appear to change. However, they are in a constant state of change

4. Long Term Climatic Changes Ice Ages Interglacial Intervals

5. Ice Ages - period of extensive glacial coverage. There have been several glacial advances and retreats

7. Interglacial Intervals - Warm periods between glaciation

8. Short Term Climatic Changes Seasons El Nino

9. Seasons - regular variations in daylight, temperature, and weather patterns

11. El Nino - Weakening of the equatorial current brings warmer waters to the west coast of South America

13. Evidences of Climatic Change

14. - Tree Rings - Ice Core Samples - Fossils - Radio Carbon Samples

16. Causes for Change

17. Human Activity - Pollution may aid global warming

19. Volcanic Activity - Dust blocks solar radiation lowering global temperatures

21. Solar Activity - increased solar activity causes increased global temps. 11yr cycle

23. Earth’s Orbit - More circular orbit = cooler global temps. 100,000 yr cycle

25. Earth’s Wobble - Reversal of Earth’s Tilt reverses seasons. 26,000 yr cycle