Revised Papers due April 17

1. Revised Papers due April 17 • Strunk and White, The Elements of Style. Note: The guidelines indicated in the “Revisions Instructions” (posted on the web) must be followed precisely for the revised paper to be accepted.

2. Global Warming NEWS: later

3. NEWS: Wilkens Ice Shelf is disintegrating

4. Last Class… What is the definition of a greenhouse gas? What are examples of greenhouse gases? What is the most effective greenhouse gas? NEWS: later

5. Absorbers in our Atmosphere Earth emits much of its radiation here.CO2 and H2O are the most important greenhouse gases.

6. Last Class… Power*: P = T4 For Earth: Power* out Power* In T = 253 K or -3o F 235 W/m2 235 W/m2 For Venus: Power* out Power* In T = 252 K or -3o F 229 W/m2 229 W/m2 We argued that the energy/sec of sunlight into the atmosphere equals the energy/sec out of the atmosphere. NEWS: later  = 5.67x10-8 W/m2 K4

7. Last Class… Power*: P = T4 For Earth: Power* out Power* In T = 253 K or -3o F 235 W/m2 235 W/m2 For Venus: Power* out Power* In T = 252 K or -3o F 229 W/m2 229 W/m2 We argued that the energy/sec of sunlight (and IR radiation) into the atmosphere equals the energy/sec out of the atmosphere. NEWS: later  = 5.67x10-8 W/m2 K4

8. Power balance Infrared Radiation Infrared Radiation VisibleSunlight VisibleSunlight Correction: The power of sunlight and IR light entering the atmosphere equals the power of IR light exiting the atmosphere Our assumption: The power of sunlight entering the atmosphere equals the power of IR light exiting the atmosphere

9. VENUS vs EARTH * Hot enough to melt lead

10. VENUS vs EARTH * But there is 1000 times this amount on the surface!

11. Runaway Greenhouse: Recipe* • Heat Earth with CO2 , H20 evaporates. • Water further heats Earth. • More water then evaporates. • This causes more heating. • More water evaporates. • And so on. * Easier than instant pudding

12. Topic: Global WarmingScience & Society Today’s Lecture includes: Why no life on Venus? Are we affecting Earth? Saucy political intrigue. NEWS: later

14. The Increase in CO2

15. Measuring Earth’s temperature Thousands of thermometers on weather stations & ships Satellite microwave emission from O2 (lower 5 km) Measure change of temperature with height. Greenhouse warming causes the lower 5-10 km to heat and above to cool. Make measurements throughout the day, everyday. Isotopic composition in ice cores (Past climate) Coral growth (Past climate) Tree ring widths. (Past climate) Human records, e.g. the freezing of the Thames (London). Harvard Research Date by counting layers, Volcanic eruptions… Colder temperatures: lighter H & O isotopes (for which H2O has a higher vapor pressure). USGS core lab

16. Evidence that Earth is warming Reconstruction of the Northern Hemisphere temperatures coral and ice-core proxy records (Mann et al. 1999, 1998, Jones & Briff 1992)

17. Figure 3.1 IPCC

18. Intergovernmental Panel on Climate Change February 9, 2007, Paris

19. Figure 3.10 IPCC

20. Rising Ocean temperatures The Atlantic, Pacific and Indian oceans have warmed by 0.06 C in since 1955 (Science, 24 March 2000, pg 2225). This result was determined by compiling millions of measurements of the deep oceans made from 1948 to 1995. More recently (Science, 13 April 2001), climate calculations indicate that the anthropogenic rise in CO2 explains this sea warming. Coral reefs are dying all around the world, likely as a result of the warming of the oceans.

21. 2002 all-time record melt area • Melting up to elevation of 2000 m • 16% increase from 1979 to 2002 70 meters thinning in 5 years Increasing Melt Area on Greenland Satellite-era record melt of 2002 was exceeded in 2005. Source: Waleed Abdalati, Goddard Space Flight Center From Jim Hansen

22. Melt descending into a moulin, a vertical shaft carrying water to ice sheet base. Source: Roger Braithwaite, University of Manchester (UK) GREENLAND MELT

23. Jakobshavn Ice Stream in Greenland Discharge from major Greenland ice streams is accelerating markedly. Source: Prof. Konrad Steffen, Univ. of Colorado Greenland’s largest outlet glacier, drains 6.5% of the ice sheet. Doubling of flow speed from 1997 to 2003. Complete melting would raise sea level by 7 meters.

24. Melting Polar Ice Increasingly higher number of Polar Bears drowning. (Science 2007) The northeast passage is predicted to open up in 2050, allowing ships to sail from London to Japan along the coast of Siberia.

25. Sea levels are rising Present predictions based on glacial melt rates indicate that the sea level will rise 10-20 inches in the next century. Rate of rise is 0.1 inch since 1993 (NASA).

26. Washington New York Bangladesh Beijing Melt all of the ice sheets: 70 m increase in sea level (above scale in meters)

27. Global Warming? • Earth has warmed 1° F in the last century • The CO2 abundance has risen by 20% since 1950. • The oceans have warmed 0.06 C since 1955. • The sea level is rising 0.1 inches each year.

28. Global Warming & Society • Good word: Orwellian: 1) of or relating to the works by George Orwell, particularly the novel 1984, about a future totalitarian state. 2) A policy controlled by propoganda, misinformation and denial of truth, and manipulation of history. Political Intrigue

29. USA consumes 25% of the World’s Oil

30. USA has 4.5% of the World Population

31. World Energy Consumption 1995

32. Kyoto Protocol

35. Emission of CO2 USA 69% Oil for Transportation 92% Coal for Electricity 40% of all petroleum is expended by transportation

36. Canada Venezuela Mexico Saudi Arabia Iraq Kuwait Associate Editor / Air Force Mag.

37. Kyoto Protocol2002 • In 1997 the Kyoto Protocol was formulated. • The treaty calls for the 38 largest industrial nations to reduce emissions due to greenhouse gases. • But the Protocol would not take effect until it is ratified by the nations emitting at least 55% of the greenhouse gases. • In March of 2001, the USA rejected the Protocol on the grounds that it would hurt the economy. • The USA, with 4% of the world population, produces 25% of the greenhouse gases. The protocol would require the USA to reduce the emissions by 7% by 2010. • In June 2002, the European Union and many other countries, including Japan, proceeded to ratify the Protocol, without the USA. The union of countries produce almost 55% of the greenhouse gases.

38. Kyoto Protocol 2005 • Green: signed & ratified • Yellow: ratification pending • Red: signed, refused ratification • Grey: not involved

39. Article in Le Monde (2004)

40. 2005 60 Minutes interview with Dr. James Hansen

41. Paris vs Tucson 1960 metro stops in Paris!

42. LONDON

43. Summary: Global Warming • The CO2 abundance has risen by 20% since 1950. • Earth’s atmosphere has warmed 1° F in the last century. • Oceans have warmed 0.06 C since 1955 • The sea level is rising 0.1 inches each year • If Greenland melts, the sea level will rise 7.2 m • If Antarctic ice sheet melts the sea will rise 61 m

44. Sources of Information • Primary Sources: • Science http://www.sciencemag.org/ • Nature http://www.nature.com/nature/index.html • Secondary Sources: • Scientific American http://www.sciam.com/ • USA Scientists: National Academy of Sciences • http://www.nasonline.org/site/PageServer • International Panel: IPCC* (http://www.ipcc.ch/) * Intergovernmental Panel on Climate Change (Nobel Peace Prize along with Al Gore)