1. Global Climate Change
November 2, 2012

2. …explain the causes and effects of global warming.
I will…
…explain the causes and effects of global warming.

3. Weather vs. Climate Climate = long term atmospheric conditions
Weather = short term and localized atmospheric condition
TPS Question: If there is a snow storm, does that mean that global warming does not exist? Why or why not?

4. Earth’s Climate
Controlled by:
Atmosphere
Sun
Ocean

5. Earth’s Climate Major factors shape the earth’s climate: The sun.
Greenhouse effect that warms the earth’s lower troposphere and surface because of the presence of greenhouse gases.
Oceans store CO2 and heat, evaporate and receive water, move stored heat to other parts of the world.
Natural cooling process through water vapor in the troposphere (heat rises).

6. WHAT DOES ANTHROPOGENIC MEAN?
THROWBACK
WHAT DOES ANTHROPOGENIC MEAN?

7. The Atmosphere
Greenhouse gases – atmospheric gases that absorb radiated heat very effectively
Water Vapor
Ozone
Carbon Dioxide
Nitrous Oxide
Methane

8. Major Greenhouse Gases
The major greenhouse gases in the lower atmosphere are water vapor, carbon dioxide, methane, and nitrous oxide.
These gases have always been present in the earth’s troposphere in varying concentrations.
Fluctuations in these gases, plus changes in solar output are the major factors causing the changes in tropospheric temperature over the past 400,000 years.

9. Major Greenhouse Gases
Increases in average concentrations of three greenhouse gases in the troposphere between 1860 and 2004, mostly due to fossil fuel burning, deforestation, and agriculture.
Figure 20-5

10. Figure 20.5
Science: increases in average concentrations of three greenhouse gases—carbon dioxide, methane, and nitrous oxide—in the troposphere between 1860 and 2005, mostly because of fossil fuel burning, deforestation, and agriculture. The fluctuations in the CO2 curve (top) reflect seasonal changes in photosynthetic activity, which cause small differences between summer and winter concentrations of CO2. (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and World Resources Institute)
Fig. 20-5a, p. 467

11. Figure 20.5
Science: increases in average concentrations of three greenhouse gases—carbon dioxide, methane, and nitrous oxide—in the troposphere between 1860 and 2005, mostly because of fossil fuel burning, deforestation, and agriculture. The fluctuations in the CO2 curve (top) reflect seasonal changes in photosynthetic activity, which cause small differences between summer and winter concentrations of CO2. (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and World Resources Institute)
Fig. 20-5b, p. 467

12. Figure 20.5
Science: increases in average concentrations of three greenhouse gases—carbon dioxide, methane, and nitrous oxide—in the troposphere between 1860 and 2005, mostly because of fossil fuel burning, deforestation, and agriculture. The fluctuations in the CO2 curve (top) reflect seasonal changes in photosynthetic activity, which cause small differences between summer and winter concentrations of CO2. (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and World Resources Institute)
Fig. 20-5c, p. 467

13. THIS IS KNOWN AS THE GREENHOUSE EFFECT!
The Atmosphere
As these greenhouse gases absorb the heat, they warm the planets surface
THIS IS KNOWN AS THE GREENHOUSE EFFECT!
Some gases can warm the planet more than others  this is known as the global warming potential of the gas

14. The Atmosphere
Carbon dioxide is considered weaker than methane or nitrous oxide but there is A LOT MORE OF IT in the atmosphere
Therefore, it contributes more to the greenhouse effect
Human activity mostly produces carbon dioxide which makes us contributors to global warming

15. The Sun The sun supplies Earth’s energy
The atmosphere, clouds, land, ice, and water together absorb 70% of incoming solar radiation
The remaining 30% is reflected back into space
Solar output refers to the amount of radiation the sun emits
It varies during different Milankovitch Cycles

16. The Ocean The ocean holds 50 times more carbon than the atmosphere
It absorbs carbon directly from the atmosphere and through photosynthesis of marine plants
PROBLEM: We are adding carbon dioxide to the atmosphere faster than the ocean can absorb it!

17. PAST CLIMATE AND THE GREENHOUSE EFFECT
Figure 20-2

18. Average temperature over past 900,000 years
Average surface temperature (°C)
Figure 20.2
Science: estimated changes in the average global temperature of the atmosphere near the earth’s surface over different periods of time. Although a particular place might have much lower or much higher readings than the troposphere’s average temperature, such averages provide a valuable way to measure long-term trends. QUESTION: What two conclusions can you draw from these diagrams? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Agency, National Center for Atmospheric Research, National Oceanic and Atmospheric Administration)
Thousands of years ago
Fig. 20-2a, p. 465

19. Average temperature over past 130 years
Average surface temperature (°C)
Figure 20.2
Science: estimated changes in the average global temperature of the atmosphere near the earth’s surface over different periods of time. Although a particular place might have much lower or much higher readings than the troposphere’s average temperature, such averages provide a valuable way to measure long-term trends. QUESTION: What two conclusions can you draw from these diagrams? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Agency, National Center for Atmospheric Research, National Oceanic and Atmospheric Administration)
Year
Fig. 20-2b, p. 465

20. Temperature change over past 22,000 years
Agriculture established
Temperature change (C°)
End of
last ice
age
Average temperature over past
10,000 years = 15°C (59°F)
Figure 20.2
Science: estimated changes in the average global temperature of the atmosphere near the earth’s surface over different periods of time. Although a particular place might have much lower or much higher readings than the troposphere’s average temperature, such averages provide a valuable way to measure long-term trends. QUESTION: What two conclusions can you draw from these diagrams? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Agency, National Center for Atmospheric Research, National Oceanic and Atmospheric Administration)
Years ago
Fig. 20-2c, p. 465

21. Temperature change over past 1,000 years
Temperature change (C°)
Figure 20.2
Science: estimated changes in the average global temperature of the atmosphere near the earth’s surface over different periods of time. Although a particular place might have much lower or much higher readings than the troposphere’s average temperature, such averages provide a valuable way to measure long-term trends. QUESTION: What two conclusions can you draw from these diagrams? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Agency, National Center for Atmospheric Research, National Oceanic and Atmospheric Administration)
Year
Fig. 20-2d, p. 465

22. How Do We Know What Temperatures Were in the Past?
Scientists analyze tiny air bubbles trapped in ice cores learn about past:
troposphere composition.
temperature trends.
greenhouse gas concentrations.
solar, snowfall, and forest fire activity.
Figure 20-3

23. How Do We Know What Temperatures Were in the Past?
In 2005, an ice core showed that CO2 levels in the troposphere are the highest they have been in 650,000 years.
Figure 20-4

24. Concentration of carbon dioxide
in the atmosphere (ppm)
Carbon dioxide
Variation of temperature (C°)
from current level
Figure 20.4
Science: atmospheric carbon dioxide levels and global temperature. Estimated long-term variations in average global temperature of the atmosphere near the earth’s surface are graphed along with average troposphere CO2 levels over the past 160,000 years. The rough correlation between CO2 levels in the troposphere and temperature shown in these estimates based on ice core data suggests a connection between the two variables. In 2005, an ice core showed that CO2 levels in the troposphere are the highest they have been in 650,000 years. QUESTION: What are the implications of these data on your lifestyle now and in the future? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and Physics Institute at the University of Bern, Switzerland)
Temperature change
End of last ice age
Thousands of years before present
Fig. 20-4, p. 466

25. CLIMATE CHANGE AND HUMAN ACTIVITIES
Evidence that the earth’s troposphere is warming, mostly because of human actions:
The 20th century was the hottest century in the past 1000 years.
Since 1900, the earth’s average tropospheric temperature has risen 0.6 C°.
Over the past 50 years, Arctic temperatures have risen almost twice as fast as those in the rest of the world.
Glaciers and floating sea ice are melting and shrinking at increasing rates.

26. CLIMATE CHANGE AND HUMAN ACTIVITIES
Warmer temperatures in Alaska, Russia, and the Arctic are melting permafrost releasing more CO2 and CH4 into the troposphere.
During the last century, the world’s sea level rose by cm, mostly due to runoff from melting and land-based ice and the expansion of ocean water as temperatures rise.
Finish Day 1

27. Why Should We Be Concerned about a Warmer Earth?
A rapid increase in the temperature of the troposphere during this century would give us little time to deal with its harmful effects.
As a prevention strategy scientists urge to cut global CO2 emissions in half over the next 50 years.
This could prevent changes in the earth’s climate system that would last for tens of thousands of years.

28. Global Warming – Greenhouse Effect

29. The Scientific Consensus about Future Climate Change
Measured and projected changes in the average temperature of the atmosphere.
Figure 20-7

30. The BIG Problems
Burning coal creates power but releases gases that help to drive Global Warming.
Arctic regions are heating up causing glaciers to melt, dumping water in the oceans.
Severe weather including rainstorms, flooding, droughts, and hurricanes are disrupting lives.
Wildfires caused by parched and arid conditions.
Droughts turn fertile land into deserts, uprooting communities and sparking violence.

31. Sea Levels
Global sea levels have risen 4 in. to 8 in. during the 20th century.
Global sea levels are anticipated to rise 19 in. to 37 in. during the 21st century if the current trend continues.
If the entire Greenland ice sheet were to melt, the seal level would rise an additional 23 feet.

32. EFFECTS OF GLOBAL WARMING
Between 1979 and 2005, average Arctic sea ice dropped 20% (as shown in blue hues above).
Figure 20-8

33. Planet Earth – Sea Levels

34. Rising Sea Levels
During this century rising seas levels are projected to flood low-lying urban areas, coastal estuaries, wetlands, coral reefs, and barrier islands and beaches.
Figure 20-10

35. Planet Earth – Sea Level Change impact

36. Rising Sea Levels
If seas levels rise by 9-88cm during this century, most of the Maldives islands and their coral reefs will be flooded.
Figure 20-11

37. Changing Ocean Currents
Global warming could alter ocean currents and cause both excessive warming and severe cooling.
Figure 20-12

38. Carbon Dioxide Levels
Greenhouse gasses rose less than 1% in the 10,000 years before the Industrial Revolution.
Greenhouse gasses have risen 33% since the Industrial Revolution.
The annual CO2 emission released by a typical 500-megawatt coal fired power plant is 3 million tons.
The U.S. has 5% of the world’s people, yet it produces 25% of the CO2 emission on the plant.

39. Carbon Dioxide Levels

40. EFFECTS OF GLOBAL WARMING
A warmer troposphere can decrease the ability of the ocean to remove and store CO2 by decreasing the nutrient supply for phytoplankton and increasing the acidity of ocean water.
Global warming will lead to prolonged heat waves and droughts in some areas and prolonged heavy rains and increased flooding in other areas.

41. Warming Trend Earth has warmed 1.44º F during the 20th century.
The total temperature rise that is anticipated in the 21st century is 1.98º F to 11.52º F if current trends continue.
11 out of the past 12 years have been ranked as the warmest in modern history

42. Planet Earth – Warming Trend

43. EFFECTS OF GLOBAL WARMING
In a warmer world, agricultural productivity may increase in some areas and decrease in others.
Crop and fish production in some areas could be reduced by rising sea levels that would flood river deltas.
Global warming will increase deaths from:
Heat and disruption of food supply.
Spread of tropical diseases to temperate regions.
Increase the number of environmental refugees.

44. Rain Forests Slash and Burn methods
Send clouds of gas into the atmosphere.
Remove trees that convert CO2 into O2.
The source of many prescription drugs.
Many natural chemicals may never be identified.

45. Deserts Higher temperatures accelerate desertification.
The land becomes too dry to support agriculture.
The lives and livelihoods of people are threatened.

46. Polar Regions Glaciers and ice shelves are melting.
Sea levels will rise and many land areas may be under water.
Rising seas could contaminate water supplies with salt.
Warmer temperatures could widen the range of disease-carrying rodents and bugs
Many species of wildlife may go extinct.

47. Coral Reefs
Slight temperature changes in water can cause coral bleaching that is devoid of life.
Higher temperatures cause the polyps to eject the algal tenants that are living within their tissues that provide the color and nutrients the coral need to survive.

48. Health Risks Allergies Carriers Water Sources
Plants like ragweed and other pollen sources will flourish under the warmer conditions.
Carriers
Hot weather could make the global mosquito populations (carriers of Malaria) explode.
Water Sources
As rainfall levels increase, older cities run a risk that overflowing sewer lines may contaminate supplies of drinking water.

49. Animals African Elephant – shrinking of range and food supply
Wild Salmon – melting permafrost pours mud into rivers, burying gravel needed for spawning
Prickly Pear Cactus – warming related changes are causing disruptions in the life cycle of plants

50. Animals
Harlequin Frog – climate changes seem to make them more vulnerable to a deadly fungus
Pinon Mouse – moving their homes to higher elevations
Quiver Tree – dyeing off and moving southward
Adelie Penguin, Polar Bears, Arctic Wolves – as polar ice melts, their habitats are endangered

51. More Powerful Tropical Storms
Over the past 35 years, the number of hurricanes each season has remained constant, but their average intensity has increased, with the number of category 4 and 5 storms (the most powerful) nearly doubling.

52. Climate Change Solutions

53. Review of Greenhouse Gases
Record the information about each type of air molecule in your notebook

54. CO2 Average time in atmosphere = 100 years Warming potential = 1
Greenhouse Gas
Sources:
Burning oil and coal
Cellular respiration
Deforestation
Volcanoes
Leads to headaches, drowsiness and fatigue
82% of GHG emissions

55. CFCs Average time in atmosphere = 15 years
100 years in stratosphere
Warming potential = 1,000-8,000
Ozone depleting chemical
Sources:
Air conditioners
Refrigerators
Foam products
Insulation
Montreal Protocol reduced production
China and Brazil still produce!

56. CH4 Average time in atmosphere = 15 years Warming potential = 25
Sources:
Rice cultivation
Coal
Natural gas leaks
Cows
Landfills (greatest source!)
Volcanoes

57. N2O Average time in atmosphere = 115 years Warming potential = 300
Sources:
Burning fossil fuels
Fertilizers
Plastic manufacturing
Livestock waste
“Laughing Gas”
Ozone depleting chemical

58. O3 Warming potential = 3,000 Good in stratosphere Bad in troposphere
Sources:
Combustion of fossil fuels mixing with heat and Nox
Photocopiers, electrical equipment
Major component of smog
Damages human tissue, respiratory problems

59. SF6 Average time in atmosphere = 3,200 years
Warming potential = 24,000
Sources
Electrical industry as a replacement for PCBs (circuit breakers, insulators, etc.)
Magnesium production industry

60. Review of Effects
Acidification  lower pH of sea water due to more carbon dioxide
Changes in weather patterns
Displacement of people  relocation needed
Forest Fires
Glaciers Melting
Increased disease
Loss in economic development
Methane released in permafrost
Rise in seas level
Change in ocean currents

61. Methods to Reduce Climate Change
Increase efficiency of cars
Move to more renewable sources of energy (wind, solar, geothermal, etc.)
Find chemical substitutes that do not impact global warming
Slow down the rate of deforestation and encourage reforestation
Reduce dependence on inorganic, nitrogen-based fertilizers and utilize soil conservation techniques
Support treaties and protocols that require reductions in greenhouse gas emission

62. Take Aim at Climate Change
Watch this!

63. Answer in notebook What was the purpose/goal? What year did it happen?
Who ratified it?
What were some pros?
What were some cons?
Was it effective? Why or why not?

64. Kyoto Protocol
UNFCCC commits its parties by setting internationally binding emission reduction targets (GHGs go down)
Developed countries are the primary target
Adopted in 1997 and went into effect in 2005
The first commitment period ended on Dec. 2012
Canada, US (never ratified), Japan, Russia, and New Zealand withdrew for second round

65. Montreal Protocol
International treaty designed to phase out substances responsible for ozone depletion
If adhered to, ozone will recover by 2050
Most effective international agreement to date
Most widely ratified treaty
HFCs replaced CFCs  no damage to ozone, but extremely potent GHGs
1989

66. Copenhagen Accord UNFCCC document Not legally binding
Notes that climate change is a problem and promotes the Kyoto Protocol
Calls for an assessment of implementation
Dec. 2009