1. CAUSES OF CLIMATE CHANGE

2. Man-made causes of climate change
Burning fossil fuels
Farming by-products
Deforestation (no trees to take in CO2)

3. Earth’s climate history
Has always been changing

4. NATURAL CAUSES OF CLIMATE CHANGE

5. VOLCANOES Depends on type of eruption
Emit CO2- warms- mainly lava flows- long term
Ash blocks sun- cools- short term

6. Natural Climate Change: Volcanic Eruptions
Effect of ash and SO2
Ex: Mt. Pinatubo (1991)
Backup site

8. Milankovitch cycles Earth orbit changes shape Earth’s tilt changes
More elliptical= cooler
Earth’s tilt changes
Precession- tilt wobbles
Less tilt= less seasons

9. Variation in Solar radiation
Sunspots
solar storms= hotter
11 year cycle

10. Scientific American
The authors calculated a net warming value of around 0.5 degree C since the 1950s. Changes in solar radiation—a hypothesis for global warming proffered by many climate skeptics—contributed no more than around 0.07 degree C to the recent warming, the study finds.

11. Polls of Climatologist

13. NASA
As the Earth moved out of ice ages over the past million years, the global temperature rose a total of 4 to 7 degrees Celsius over about 5,000 years. In the past century alone, the temperature has climbed 0.7 degrees Celsius, roughly ten times faster than the average rate of ice-age-recovery warming.

14. U.S. EPA

15. Spiraling temperature GIF

16. So….
Is the current climate change natural or man-made?
article

17. Effects of global warming
Rise in sea level
Coasts underwater
More storms/hurricanes
Melt permafrost
More deserts
Coral reefs die (bleaching)
Algae blooms

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

19. Global warming can cause global cooling?

20. Day after Tomorrow Trailer (2004)

21. Current state of glaciers

22. Glacier national Park, Montana 1938 vs. 2005

23. Alaska 1917 vs. 2005

24. Greenland notice

26. What can be done?

27. PARIS PROTOCOL
2016
Goal is to get global temps. below pre-industrial revolution temps. (reduce by 2°C)
195 countries
US will reduce CO2 emissions by 26% by 2025

28. CON

29. What can we do to reduce greenhouse gases? (add to review)
Use less electricity
More efficient appliances/light bulbs
Alternative energy sources
Drive less
hybrids

30. I encourage you to do more research!
Have an open mind!

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