1. What is Climate Change?
Long term changes in the Earth’s heat budget resulting from radiative inbalance
can result in a colder or warmer climate

2. Ice Ages
There have been many ice ages on Earth, as well as many warm climate periods

3. What is an Ice Age?
Ice ages are periods when glaciers grow to cover large portions of continents
Another term for this is continental glaciation
Unlike alpine glaciers which are restricted to valleys, continental glaciers advance along a wide front and cover large areas. 
Currently, Greenland and Antarctica are the sites of most of the world’s continental glaciation

4. ~22,000 years ago, Albany was under more than a mile of ice
Glaciers sculpted much of New York’s landscape

5. What causes ice ages?
There are several factors that contribute to global climate change and glaciation events. Among them are:
Continental Drift
Continents must be at or near poles
Changes in oceanic and atmospheric circulation
Mountain building
Variations in the Earth’s orbit around the Sun
Variations in the albedo of the earth’s surface and atmosphere
One of these factors is not enough; a combination of factors favorable to glaciation is required

6. Prior to relatively recent Ice Ages, there were four periods of major glaciation or “icehouse” times
Permian-Carboniferous
Late Ordovician
Late Proterozoic
Earliest Proterozoic

7. Continental Drift
Plates can move from low latitudes to high latitudes. Land at the poles helps promote glaciation.
Plate reorganization can also cause changes in oceanic and atmospheric circulation that can trigger significant global climate change. It is essential that warm moist air be circulated towards the poles.
Mountain building events caused by plate collisions can also help to trigger glaciation

8. Closure of the Isthmus of Panama caused reorganization of major oceanic currents and helped bring on major Northern Hemisphere glaciation over the last 3 million years
The closure occurred about 4 million years ago. After a lag of about 1million years, the glaciations began

10. Ocean circulation & Climate

11. What causes changes in the heat budget?
1) Changes in the sun’s energy output: sunspots

12. What causes changes in the heat budget?
2) Changes in the Earth’s orbit and tilt:

13. What causes changes in the heat budget?
3) Volcanic eruptions: aerosols cause cooling

14. What causes changes in the heat budget?
4) Humans:
a) overgrazing causes desertification

15. What causes changes in the heat budget?
4) Humans:
b) deforestation makes air drier

16. What causes changes in the heat budget?
4) Humans:
c) urbanization

17. What causes changes in the heat budget?
4) Humans:
d) burning fossil fuels makes greenhouse gases, the current major cause of GLOBAL WARMING

18. Global Warming

19. Greenhouse Effect Greenhouse gases are: Methane Water vapor
Carbon dioxide
Reradiated from surface

20. Short wave light
Long wave
infrared

21. Summary

22. Short waves
Long waves

23. Scientists agree
that over the past few
decades the earth has
been heating up, primarily due to
human activities

24. This in turn could cause rises
in sea level by as much as 20
feet or higher, flooding much
of the worlds coastal areas
and many major cities.
A significant rise in world
Wide temperature could
Melt the Antarctic Ice Fields

26. The flood waters move in steadily

27. For example: A rise in sea level of 20 feet would
flood all of the parts of Florida that are green

28. Ok, we get the point,
Turn down the heat.

29. I’m wilting If temperatures are increasing world wide as a result of
greenhouse gases,
the effect is
known as
Global Warming
I’m wilting

30. The 800 degree temperatures
on Venus are the result
of a runaway greenhouse
effect
Venus has more than
1000 times more CO2
in it’s atmosphere
than earth