1. 10.3 Global Climate Change

2. Warm-up Essential Question
What main factors contribute to climate? What happens if one of these factors changes?
Essential Question
What are the causes and impacts of climate change?

3. Climate Change- Mean Annual Global Temperature 1880-2015

4. First… Climate change vs. global warming
Global warming is average temperatures for the WHOLE PLANET, which is increasing
Climate change is the change in regions because of that global change

5. Climate Change Terminology
Greenhouse Gas
Gas that absorbs infrared radiation
Ex: Carbon dioxide, methane, nitrous oxide, chlorofluorocarbons and tropospheric ozone
Positive Feedback
Change in some condition triggers a response that intensifies the changed condition
Infrared Radiation
Radiation that has a wavelength that is longer than that of visible light, but shorter than that of radio waves
Greenhouse Effect
Increase of heat in a system where energy enters (often as light), is absorbed as heat, and released sometime later

6. Climate Change Evidence for Climate Change
Last decade is the hottest ever recorded
The three hottest years ever recorded were the last 2015, 2016, and 2017
Phenological spring in N. hemisphere now comes 6 days earlier (phenological is based on times of plants emerging)
Warming is not due to natural causes
Human produced greenhouse gases are most plausible explanation

8. Causes Greenhouse gas concentrations increasing 2017 concentrations
408 ppm
1,834 ppb
328ppb
516ppt
232ppt

9. Causes Increased concentration of CO2 (right)
Burning fossil fuels in cars, industry, and homes
Deforestation
Burning of forests

12. Greenhouse Effect

13. Other Pollutants Cool the Atmosphere
Atmospheric Aerosols tend to cool the atmosphere
Both human and natural sources
Tiny particles that remain in troposphere for weeks or months
Contain many chemicals, but often contain sulfur (makes acid rain – remember Venus)
Complicates models of climate change
Allows for people to argue.

14. Climate Change- Mean Annual Global Temperature 1880-2015

15. Climate Models Climate affected by:
winds, clouds, ocean currents, and albedo
Used to explore past climate events
Advanced models can project future warming events
Models are only as good as the data and law used to program them
They have limitations

16. Climate Models

18. Effects of Global Climate Change
Ocean as CO2 sink - excess CO2 is starting to harm ocean life

19. Effects of Global Climate Change- Melting Ice and Rising Sea Levels
Sea level rise caused in 2 ways
Thermal Expansion
Water expands as it warms
Melting of land ice
Retreat of glacier and thinning of ice at the poles
Melting has positive feedback
Increased melting decreases ice, which decreases albedo leading to further warming

22. Melting Ice and Rising Sea Levels

23. Migration of barrier islands
There will always be islands off the shore of the East coast, but they are moving because sea level is rising

24. Case-In-Point Impacts in Fragile Areas
Eskimo Inuit live traditional life dictated by freezing climate
Climate change is altering their existence
Wildlife are smaller or displaced
Reduced snow cover and shorter river ice seasons
Thawing of permafrost (right)

25. Effects of Global Climate Change- Changing Precipitation Patterns
Some areas will get more water, some areas will have greater droughts
Extreme weather events will increase in number and intensity
Ex: Hurricanes will likely get stronger and more frequent

27. Effects of Global Climate Change- Effects on Organisms
Zooplankton in parts of California Current have decreased by 80% since 1951
Effecting entire food chain
Decline in krill around Antarctica
Caused decrease in penguin populations
Species have shifted their geographic range
Migrating birds are returning to summer homes earlier
Food is not available at this time

28. Effects on Organisms - Coral Reefs
Coral reefs can be bleached (right) due to increase in water temperature
Affects coral symbiotes and makes them more susceptible to diseases to which they would otherwise be immune

29. Effect on Organisms - Vegetation Beech Tree Range

30. Effects on Human Health
Increased number of heat-related illnesses and deaths

31. Effects on Agriculture
Difficult to anticipate
Productivity will increase in some areas and decrease in others
Rise in sea level will inundate flood plains and river valleys (lush farmland)
Effect on pests is unknown
Warmer temperatures will decrease soil moisture- requiring more irrigation
Location (i.e. elevation and altitude) where certain crops can be grown may have to change
Decrease in crop yields in warm climates

32. International Implications of Climate Change
Developed vs. Developing countries
Differing self-interests
Differing ability to meet the challenges of climate change

33. Common Denial Techniques
It was cold this winter! No such thing as global warming
Remember some areas will get more extreme weather, that includes extreme cold at very specific times
Its about averages not specific locations

34. Common Denial Techniques
It’s from the sun, the solar activity is warming the planet
Actually solar activity hasn’t changed drastically
Our atmosphere protects us from most of that
Activity doesn’t match temperature

35. Common Denial Techniques
Climate computer models are uncertain
Nope. They could accurately predict the climate from the last 100 years. There is a very small margin of error on those models

36. Common Denial Techniques
Carbon dioxide is plant food so its good
This only applies when it’s in balance

37. Common Denial Techniques
Antarctic sea ice is expanding
Only because it’s coming off the land
Also, it does in the winter every year but it’s less than it should be

38. Common Denial Techniques
Well some people have data that says it’s not actually getting any warmer and it doesn’t correlate with CO2
This data is hacked
Displayed skewed on the graph
Taken from ONLY one place

39. “There were rumors of unfathomable things, and because we could not fathom them we failed to believe them, until we had no choice it was too late.”