1. PALEOCLIMATES
Ancient climates
11/22/2018

2. 11/22/2018

3. 11/22/2018

4. Earth’s climate history
Has always been changing

5. Earth’s climate has always been changing
11/22/2018

6. How do we study past climates???
11/22/2018

7. Fossils Certain critters only live in WARM climates Trilobites
Corals (Petoskey stones)
dinosaurs
11/22/2018

8. Glacial evidence Indicates COLD climate Grooves Erratics
Misplaced boulders
11/22/2018

9. Ice cores Ancient air bubbles are trapped in the ice
Can analyze ancient air!
11/22/2018

10. 18O/ 16O 18O is heavier- harder to evaporate
More 18O when climate is hotter
Seen in ice cores
11/22/2018

11. 11/22/2018

12. Tree rings
Wider rings represent warm wet climate
11/22/2018

13. Coral reefs Corals add layers every year Like tree rings
Bigger layer= warmer
11/22/2018

14. NATURAL CAUSES OF CLIMATE CHANGE

15. VOLCANOES Lava type= Emit CO2; warms- long term (need a lot!)
Ash type= emit SO2- blocks heat- cools- short term

17. Impact events (space rocks)
1) Stirs up dust= colder

18. Milankovitch cycles Earth tilt changes Less tilt= less seasons
Cooler in mid latitudes
Ice age! OR
Earth’s orbit becomes
More oval= colder

19. Variation in Solar output
Sunspots
Cause solar storms
Make earth hotter

20. Land vs. sea ice
Melting of sea ice (icebergs) will NOT effect sea level
Melting of land ice will effect sea level
Antarctica/ Greenland
Could also cause global cooling (Day After Tomorrow)

21. Global warming can cause global cooling?

22. Rising sea level by 2080 (projected)

23. Current state of glaciers

24. Glacier national Park, Montana 1938 vs. 2005

25. Alaska 1917 vs. 2005

26. Greenland notice

28. Carbon footprint
Your impact on GHGs.
Extra credit!!