1. Climate Change

2. climate puzzle
taking earth's temperature
sun spots

3. Global Climate Change
Global climate change: An overall rise or fall in global temperatures
Happens slowly over time and has several causes
When temperatures rise, there is more evaporation of water
When there is more evaporation of water, there is more precipitation

4. Melting and growing ice sheets
Weather interactive

5. Questions Scientists are trying to answer…
Natural vs. Human impact
Is the global warming that is happening now part of Earth’s natural cycle?
Are humans causing climate change?
CAN humans cause climate change?
What can humans do to stop climate change?
Can we control it?
How will we adapt to climate change?

6. Natural Causes of Climate Change
1. The Greenhouse effect: gases trapping heat inside Earth’s atmosphere

7. Greenhouse Gases
Greenhouse gas: any gas that absorbs radiation from the sun
Carbon Dioxide CO₂
Carbon Monoxide CO
Methane CH₄
Nitrous Oxide N₂O
Water Vapor H₂O
Sulfur Dioxide SO₂

8. Natural Causes of Climate Change
2. Ice Age: The long term reduction of Earth’s overall temperature
Happens every 10,000 to 50,000 years naturally

9. Ice Age Data

10. Natural Causes of Climate Change
3. Solar Activity: Increased solar activity causes higher temperatures

11. Solar Cycles

12. Natural Causes of Climate Change
4. Volcanic Activity: Volcanoes release greenhouse gases in the atmosphere
Outgassing releases Water vapor, CO₂, and sulfur dioxide (SO₂)

13. Volcanic Activity
Eruptions release 2000 to 5000 tons of CO₂ into the atmosphere
Non-active volcanoes release ~100 tons of CO₂ per day

14. Natural Causes of Climate Change
5. The Milankovitch Theory: variations in earth’s rotation on its axis and orbit around the sun causes climate changes over time
The tilt of the earth changes every 40,000 years
The earth’s orbit around the sun changes every 25,000 years

15. Human Causes of Climate Change
Industrialization: burning fossil fuels puts more CO₂ into the atmosphere
CO₂ levels have increased in the last 200 years
Driving cars, electricity, factories

16. Human Causes of Climate Change
2. Deforestation: Cutting down forests leaves less plants to take up CO₂

17. Human Causes of Climate Change
3. Ozone Depletion: The ozone layer is being depleted by CFC gases
The hole in the ozone layer allows more UV radiation into earth’s atmosphere

18. ask a climatologist
measuring climate change
collecting seafloor sediments
part 1/5

19. Measuring Climate Change
Fossil Records: tropical plants and animal fossils are found in Antarctica
Climates had to have been warmer in the past

20. Measuring Climate Change
2. Ice Core Data: Air molecules get trapped when water freezes
Scientists analyze the air and can tell what the climate was like

21. Measuring Climate Change
3. Sea Floor Sediments: Measuring the chemical composition of ancient sea life tells us what the temperatures were like
sea floor sediment

22. Measuring Climate Change
4. Tree Rings: Tree ring width indicates past climate conditions
Oldest tree 9550 years old
tree rings

23. climate change
the great global warming swindle
climate change bill nye

24. Possible Impacts of Climate Change
Global Warming: global temperatures have increased by about 1⁰ C in the past 100 years
Human causes, natural causes or both?

25. Possible Impacts of Climate Change
2. Changes in Precipitation: some areas will get more, some areas will get less

26. Possible Impacts of Climate Change
3. Weather: severe weather may become more frequent
Warmer oceans make it easier for storms to form
Storms will be more intense and bring more rain
nasa

27. Possible Impacts of Climate Change
4. Sea level rise: ice at the poles melting could lead to sea level rise and the melting could cause flooding in coastal areas