1. Internal Structure and Geological History Internal structure of Mercury, Mars, and the Moon, compared to Earth

2. Atmospheric Evolution on Earth, Venus, and Mars At formation, planets had primary atmosphere – hydrogen, helium, methane, ammonia, water vapor – which was quickly lost. Secondary atmosphere – water vapor, carbon dioxide, sulfur dioxide, nitrogen – comes from volcanic activity. Earth now has a tertiary atmosphere, 20 percent oxygen, due to the presence of life.

3. Earth has a small greenhouse effect; it is in equilibrium with a comfortable (for us) surface temperature. Atmospheric Evolution on Earth, Venus, and Mars

4. Venus ’ s atmosphere is much denser and thicker; a runaway greenhouse effect has resulted in its present surface temperature of 730 K.

5. The Habitable Zone or “The Goldilocks Problem” In the zone …

6. Earth's Atmosphere 78% Nitrogen 21% Oxygen gas is ionized by solar radiation ozone is O 3, which absorbs solar UV efficiently, thus heating stratosphere commercial jet altitudes temperature on a cool day Original gases disappeared. Atmosphere is mostly due to volcanoes and plants!

7. Ozone Hole over Antarctica Led to banning of Chlorofluorocarbons worldwide Had been used in refrigerators/air conditioners, aerosol cans, and as a cleaning solvent

8. Intergovernmental Panel on Climate Change (IPCC – UN Agency) says Translating terminology into probabilities

9. Intergovernmental Panel on Climate Change (IPCC – UN Agency) says What does this mean? The consensus of the IPCC is that there is a 90% probability that human activity contributed signifcantly to the 1 degree F increase in global temperature over the past 50 years.

10. About 2 degrees F since 1850

11. Temperature for last 14,000 years

13. Burning carbon-containing fossil fuels produces carbon dioxide. (Combustion) C + O 2 CO 2 Global Warming Basics Burning Fossil Fuels is the Primary Cause Global Warming: The Greatest Threat © 2006 Deborah L. Williams

14. Global Warming Basics Global Warming: The Greatest Threat © 2006 Deborah L. Williams  Humans have increased carbon dioxide (CO 2 ) in the atmosphere by more than 35% since the Industrial Revolution. (National Oceanic and Atmospheric Administration 2006)  The most carbon dioxide in 650,000 years. (IPCC 2007)  Jan 2011 – 390.67 PPM Jan 2012 – 392.76 PPM  80% of all greenhouse gas emissions (National Library of Medicine) (CO 2 ) 10,000 BC 2009 391ppm

15. CO 2 in Atmosphere and Temperature Note variation vs. local change

16. CO 2 in Atmosphere and Temperature

17. Temperature Predictions.

18. CO 2 in Atmosphere and Temperature

19. CO 2 in Atmosphere

20. Temperature Predictions.

21. Alaska is Ground Zero Chapman and Walsh, 2004 In past 50 years, Alaska: Temperatures have increased 4 o F overall (National Assessment Synthesis Team) Worldwide: Temperatures have increased Slightly more than 1 o F (IPCC 2007) Surface Air Temperature Trends 1942-2003 Global Warming Basics Global Warming: The Greatest Threat © 2006 Deborah L. Williams Chapman and Walsh, 2004

22.  Snow and sea ice reflect 85-90% of sun’s energy.  Ocean surface and dark soil reflect only 10-20%. The Albedo Effect “White shirt versus Black shirt” Why has Alaska warmed the most? Increased melting of snow and sea ice Increased melting of snow and sea ice More of sun’s heat energy is absorbed More dark earth and ocean surface is exposed More dark earth and ocean surface is exposed Land or water warms faster Global Warming Basics Global Warming: The Greatest Threat © 2006 Deborah L. Williams (ACIA 2004)

23. Source ACIA, 2004 Jennifer Allen Animation  An area twice the size of Texas has melted away since 1979 (over 20% decrease). (National Snow and Ice Data Center 2005)  Ice 40% thinner. (Rothrock,D.A, et al. 1999)  Ice only 6 – 9 feet thick at North Pole ( NOAA FAQ 2007).  Northwest passage opened Aug 21, 2007 Impacts in Alaska 1. Melting Melting Sea Ice 1978 1983 1988 1993 1998 2003 98769876 -------- | | | | | Arctic Sea Ice Extent (millions of sq. km.) Source: NSIDC, 2005 ARCTIC SEA ICE AREA 1979-2005 2005 Global Warming: The Greatest Threat © 2006 Deborah L. Williams

24. Impacts in Alaska 1. Melting  The rapid retreat of Alaska’s glaciers represents about 50% of the estimated mass loss by glaciers through 2004 worldwide. (ACIA 2004)  Loss of over 588 billion cubic yards between ’61 and ’98. (Climate Change 11/05)  Alaska’s glaciers are responsible for at least 9% of the global sea level rise in the past century. (ACIA 2004) 1941 2004 Glacier Bay (Riggs Glacier) USGS photo Bruce Molnia photo Glacial Retreat 2003 Matt Nolan photo Austin Post photo 1958 McCall Glacier

25. Polar bears Walruses Ice seals Black guillemots Kittiwakes Salmon Caribou Impacts in Alaska 3. Animals Animals at Risk  Rising temperatures  Shrinking habitat  Food harder to get  Expanding diseases  Competition Polar bears Walruses Ice seals Caribou Black guillemots Kittiwakes Salmon Arctic grayling

26. Ocean Acidification CO 2 + H 2 0 HCO 3 - + H + Water becomes more acidic. (ACID) Remains in the atmosphere (greenhouse gas) Dissolves in sea water CO 2 Over the last 200 years, about 50% of all CO 2 produced on earth has been absorbed by the ocean. Global Warming: The Greatest Threat © 2006 Deborah L. Williams (Royal Society 6/05)

27. Inundation  Sea level has increased 3.2 mm/year between 1993 and 2008 (IPCC 2007).  This is 10-20 times faster than during the last 3,000 years (ACIA 2004).  0.4-0.6 meters of sea level rise by 2100 if 3 times pre- industrial CO2 or 1% increase/year (Overpeck et al. 2006). As Greenland and Antarctic ice sheets melt...

28. Ocean Nations Threatened Maldives nation held cabinet meeting 20 feet under water. Tuvalu nation considering exodus (highest elevation is 15 feet) New Moore Island goes under in March 2010

29. Inundation Inundation from Four Meter Sea Level Rise (or, 1m rise + 3m storm surge) Weiss and Overpeck, 2006

30. Photo courtesy of 7summits.com What We Can Do 1. Is it Achievable? 2. Action Is Essential at Every Level Individual Corporate Local State Federal International 3. Critical Steps R E D U C E C O 2 E M I S S I O N S Global Warming: The Greatest Threat © 2006 Deborah L. Williams

31. 1954 2004 2054 14 7 1. 9 Carbon Emissions (Billions of tons per year) Current Path At least TRIPLING CO 2 Avoid doubling CO 2 Flat Path STABILIZATION TRIANGLE What We Can Do Is it Achievable? Pacala and Socolow, Science 2004 Global Warming: The Greatest Threat © 2006 Deborah L. Williams

32. Inundation  Sea level has increased 3.2 mm/year between 1993 and 2008 (IPCC 2007).  This is 10-20 times faster than during the last 3,000 years (ACIA 2004).  0.4-0.6 meters of sea level rise by 2100 if 3 times pre- industrial CO2 or 1% increase/year (Overpeck et al. 2006). As Greenland and Antarctic ice sheets melt...

33. Ocean Nations Threatened Maldives nation held cabinet meeting 20 feet under water. Tuvalu nation considering exodus (highest elevation is 15 feet) New Moore Island goes under in March 2010

34. Inundation Inundation from Four Meter Sea Level Rise (or, 1m rise + 3m storm surge) Weiss and Overpeck, 2006

35. Photo courtesy of 7summits.com What We Can Do 1. Is it Achievable? 2. Action Is Essential at Every Level Individual Corporate Local State Federal International 3. Critical Steps R E D U C E C O 2 E M I S S I O N S Global Warming: The Greatest Threat © 2006 Deborah L. Williams

36. 1954 2004 2054 14 7 1. 9 Carbon Emissions (Billions of tons per year) Current Path At least TRIPLING CO 2 Avoid doubling CO 2 Flat Path STABILIZATION TRIANGLE What We Can Do Is it Achievable? Pacala and Socolow, Science 2004 Global Warming: The Greatest Threat © 2006 Deborah L. Williams

37. What We Can Do Wind Power Global Warming: The Greatest Threat © 2006 Deborah L. Williams

38. Measuring Your Carbon Footprint Major Carbon Contributors:  Electric Consumption  Gas/Heating Oil Consumption  Car and Miles Driven  Miles Flown  Recreational Vehicle Use Average Footprint is 30,000 pounds

39. Making a Difference as an Individual Conservation Measures :  Walk, bike, ride public transit, or carpool  Make sure your tires are fully inflated and your car tuned up  Lower your water heater and home thermostats  Don't preheat your oven  Only run your dishwasher with full loads  paint your roof white  Buy locally produced food  Unplug appliances not in use  Turn off lights when leaving a room  Use recycled paper  Reuse or recycle as much as you can  Cut down on consumerism

40. Conservation: Three Examples Unplug Appliances  Vampires!  43 billion kWH lost/year in US  Est: 1,000 lbs/year/person Pump Up Tires  4 million gallon of gas wasted daily in US  Extends life of tires by 25%  Est: 1,000 lbs/year/person Lower Thermostat  2 degrees  Est: 2000 lbs/year/person

41. Energy Efficiency: Two Examples Compact Fluorescents  Four to six times more efficient  Est: for each bulb converted, save about 100 lbs/year Bus/Walk/Bike  Save money on fuel and maintenance  Est: 5,000 lbs/year

42. Clicker Question: What steps are you willing to take to reduce your carbon dioxide footprint? A: Walk/bike/bus to work B: Unplug appliances when not in use C: Replace light bulbs with compact fluorescents D: Wash clothes in cold or warm water E: Buy a Prius

43. Clicker Question: A leading cause of Global Warming is: A: Increased soot (smog) in the atmosphere. B: Increased carbon dioxide in the atmosphere. C: The Earth is getting closer to the sun. D: The luminosity of the sun is steadily increasing.

44. Clicker Question: The Greenhouse effect would not occur if: A: The Earth had no atmosphere. B: The amount of carbon dioxide doubled. C: We got rid of all the forests. D: The Earth didn’t have an ocean.

45. Jovians, Moons, and Rings

46. Jupiter's Internal Structure Can't observe directly. No seismic information. Must rely on physical reasoning and connection to observable phenomena. (acts like a liquid metal, conducts electricity) Core thought to be molten or partially molten rock, maybe 25 g/cm 3, and of mass about 10-15 M Earth. Other Jovians similar. Interior temperatures, pressures and densities less extreme.

47. Jupiter has a strong magnetic field detection of the magnetic belts around Jupiter synchrotron emission from energetic particles in magnetic fields

48. Jupiter has a strong magnetic field detection of aurorae Impact of high-energy Particles at the poles.

49. Rapid rotation causes Jupiter and Saturn to bulge: Gravity without rotation with rotation Gravity Jupiter and Saturn rotate every ~10 hours. Radius at equator several % larger due to bulge.

50. Clicker Question: The Great Red Spot is: A: A large basin on Mars B: A long-lived high-pressure storm in Jupiter’s atmosphere. C: The colored polar cap of Jupiter D: Clouds of dust swirling around Jupiter’s largest volcano

51. Clicker Question: Saturn is less massive than Jupiter but almost the same size. Why is this? A: Saturn’s interior is hotter than that of Jupiter’s. B: Saturn is composed of lighter material than Jupiter. C: Saturn is rotating faster than Jupiter so the increased centrifugal force results in a larger size D: Saturn’s smaller mass provides less gravitational force to compress it.

52. Differential Rotation Rotation period is shorter closer to the equator: Jupiter Saturn Uranus Near poles At equator 9 h 56 m 10 h 40 m 16 h 30 m 9 h 50 m 10 h 14 m 14 h 12 m How do we know?

53. Differential Rotation Rotation period is shorter closer to the equator:

54. Uranus' rotation axis is tilted by 98 o Why? Unknown. Perhaps an early, grazing collision with another large body.

55. The Ice Giants - Uranus and Neptune Neptune Uranus 15 to 17 times the mass of the Earth Slushy water and methane ice atmospheres Rocky cores of ~1 Earth mass Off axis magnetic fields No large moons1 large moon (Triton) Not much internal heating3 times more internal power than solar

56. Moons of Jovian Planets

57. The Galilean Moons of Jupiter Closest to JupiterFurthest from Jupiter (sizes to scale) Radii range from 1570 km (Europa, slightly smaller than our Moon), to 2630 km (Ganymede - largest moon in Solar System). Orbital periods range from 1.77 days (Io) to 16.7 days (Callisto). The closer to Jupiter, the higher the moon density: from 3.5 g/cm 3 (Io) to 1.8 g/cm 3 (Callisto). Higher density indicates higher rock/ice fraction. Io EuropaGanymedeCallisto

58. Io's Volcanism More than 80 have been observed. Can last months or years. Ejecta speeds up to 1000 m/s. Each volcano ejects about 10,000 tons/s Rich in S, SO 2. S can be orange, red, black depending on temperature. Frozen SO 2 snowflakes are white.

59. Voyager 2 (1979) Galileo (1996) Activity causes surface to slowly change over the years:

60. Volcanic activity requires internal heat. Io is a small body. Should be cold and geologically dead by now. What is source of heat? First, Io and Europa are in a "resonance orbit": Day 0 Europa Io Day 1.77 Europa Io Day 3.55 Europa Io The periodic pull on Io by Europa makes Io's orbit elliptical. Jupiter

61. Io orbital speed slower orbital speed faster - Tidal bulge always points to Jupiter. So the angle of the bulge changes faster when Io is closer to Jupiter. (exaggerated ellipse) - But Io rotates on its axis at a constant rate. - So bulge moves back and forth across surface => stresses => heat => volcanoes

62. Europa may have Warm Ocean beneath Icy Surface 860 km 42 km Icebergs or "ice rafts" suggest broken and reassembled chunks. Dark deposits along cracks suggest eruptions of water with dust/rock mixed in (Europa’s density => 90% rock, 10% ice). Fissures suggest large moving ice sheets. Hardly any impact craters.