1. Unit 11 Notes: Climate Change
Chapter 21

2. Earth’s Heat Budget Changes in Earth’s heat budget can change climate
The heat budget is a balance between reflection and absorption.
IMPORTANT: Because 30% of the electromagnetic energy from the Sun has been reflected away, only 70% remains to interact with the Earth, and warm it up. 20% of the energy from the Sun is absorbed by the atmosphere as a whole heating it up. This leaves 50% of the Sun’s energy to heat both the surface of the Earth, as well as the oceans, lakes and streams.

3. Earth’s Heat Budget Reflection Atmosphere reflects 5%
Clouds surface reflect 20%
Earth’s surface reflects 5%
= 30% Total
If the reflection is increased, the temperature will decrease

4. Earth’s Heat Budget Absorption Atmosphere absorbs 20%
Earth’s surface absorbs 50%
= 70% Total
If the absorption is increased the temperature will increase.
Right now the temperature is increasing, one reason is due to an increase in atmospheric absorption (Greenhouse Gases)

5. How do we know climate is changing?
Evidence
Direct (to understand present climates)
Observations
Temperature
Plant life
Indirect (to predict past climates)
Sea Floor Sediments
Glacier Samples (oxygen, distribution of shells)
Tree Rings

6. Carbon Dioxide and Temperature

7. What factors cause climate change?
Earth’s Motions
Plate Tectonics
Sunspots
Volcanoes
Human Impacts

8. Earth’s Motions
Orbit
Tilt

9. Earth’s Motions Milutin Milankovitch
The Shape of Earth’s Orbit Changes
The Tilt and Axis of Rotation “Wobbles”
These can affect seasons over long periods of time, changing the climate
This is possibly the reason for changes in ice cover during the last Ice Age

10. Plate Tectonics Greenland has Tropical Plant Fossils
~200 million years

11. Plate Tectonics Can change a specific area’s climate (Greenland)
Can change global climate
Wind patterns
Ocean Currents
Ice sheets
Continents closer to poles = more ice =
more reflection of sunlight = decrease in temp
Continents farther from poles = less ice sheets =
more absorption of sunlight = increase in temp
Distributes heat differently

12. Volcanoes Mt Pinatubo (1991)
Sent 20-30mega tons of sulfurous aerosols into the air
Ash, dust, gases containing sulfur compounds
reflect sunlight into space
What would happen to temperatures?

13. Volcanoes
After the Mt Pinatubo eruption the global temperature fell ~0.5°C or 0.9°F the next year
The ash and sulfuric compounds actually reflected sunlight back into space
BUT . . .
What else do volcanoes release?
Carbon Dioxide
And What is Carbon Dioxide?

14. Volcanoes Carbon Dioxide is a Volcanoes can cause greenhouse gas
Greenhouse gases cause temperatures to increase
Volcanoes can cause
Short term cooling (aerosols and sulfuric compounds)
Long term warming (carbon dioxide)
greenhouse gas

15. Sunspots
There is an 11 year sunspot cycle that changes how much radiation is given off by the sun.
More sunspots = More energy

16. What Is Earth’s Heat Budget?
The balance between its reflection and absorption of sunlight
The balance between its temperature and air pressure
How much money it can spend monthly

17. Why Is The Earth’s Heat Budget Important?
It is the reason why we have volcanic eruptions
It causes sunspots
Changes in it can cause changes in global climate
It is a contributor to plate tectonics

18. What is the average percentage of reflection? Absorption?
20% and 80%
20% and 90%
30% and 70%
60% and 40%
70% and 30%

19. What Are Examples Of Signs That Climate Is Changing?
Observations
Temperature
Plant Life
Tree Rings
Glacier Sediments
Sea Floor Sediments
All Of The Above

20. What Factors Cause Climate Change?
Earth’s Motions
Plate Tectonics
Sunspots
Volcanoes
Human Activities
All Of The Above

21. Milutin Milankovitch Said…
Humans are the reason for global climate changes
The “wobble” of the Earth’s rotation alters seasons and climates
The Earth is absorbing less energy from the sun

22. Large Volcanic Eruptions Can Cause…
Short term cooling and long term warming
Short term warming and long term cooling
No effects to the atmosphere

23. T/F: The 11 Year Cycle Of Sunspots Changes How Much Energy The Earth Receives
True
False

24. Unit 11 Notes: Fossil Fuels

25. It is evident that climate has been changing without humans but do we have an impact on climate change?

26. Fossil Fuels Fossil fuel use is one way humans impact the planet.
Climate is affected because CO2 and other gases are emitted into the atmosphere.

27. Fossil Fuels Fossil fuels
The sun’s energy trapped within Earth’s crust
The hydrocarbons were stored mainly in plants (photosynthesis)
Can be coal, natural gas, and oil (petroleum).
Used for MANY things… not just power.

28. Fossil Fuels

29. Consequences of Fossil Fuel Use Caused by Impacts
Temperature Increase
Increased greenhouse gases in atmosphere
Break down of ocean currents, changes in climate patterns, loss of agricultural space
Pollution
Increased emission use will increase pollutants
Air quality, health risks, species loss
Sea Level Rise
Water expansion, melting of land ice (glaciers)
Loss of coastal space, species loss, changes in migration

30. Who Are The Worst Offenders Of CO2 Emissions and Energy Use?
African Countries
India
China
USA
Europe
Brazil
Australia
Middle East

31. CO2 Emissions (Per Person) SOURCE: http://en. wikipedia

32. Energy Consumption (Per Person)

33. Carbon Dioxide and Temperature
2005

34. Carbon Dioxide and Temperature Relationship
2040
2005

35. Carbon Dioxide and Temperature Relationship
“Worst Case Scenario”
(fossil intensive)
2100

36. Future Temperature Predictions

38. NASA photographs show the minimum Arctic sea ice concentration in 1979 at left and in 2003.Satellite passive microwave data since 1970s indicate a 3% decrease per decade in arctic sea ice extent.

39. Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

40. If all of the ice caps melted then sea level would raise by 65 m
Kennedy Space
Center
Impact of a 1 m
rise in sea level
on low-lying areas
If all of the ice caps melted then sea level would raise by 65 m
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

41. To sum it up. . . Climate has changed a lot over Earth’s history
There are many factors to climate change
Some we have no control over and some we do have control over
Will Earth survive if the climate changes A LOT?
Yes, but will we?

42. Humans Are The Only Reason For Global Warming
Strongly Agree
Agree
Disagree
Strongly Disagree

43. T/F: Our Reliance On Fossil Fuels Will Continue Into The Foreseeable Future…
True
False