Write a one sentence overview on what we will learn today based on this picture.

1. Write a one sentence overview on what we will learn today based on this picture.

2. Climate Change: Fitting the pieces together

3. Present day observations

5. Past Data: How do we know?

6. Is current climate change unusual? 1000 years of “proxy” surface temperatures, 100+ from thermometers National Research Council, 2006

7. Surface, balloon, & satellite temperatures agree Hadley Centre, 2003

8. Climate ModelingNOAA’s New Supercomputer “Gala”

9. The smoking gun Essentially all of the observed climate-change phenomena are consistent with the predictions of climate science for GHG-induced warming. No alternative “culprit” identified so far – no potential cause of climate change other than greenhouse gases – yields this “fingerprint” match. A credible skeptic would need to explain both what the alternative cause of the observed changes is and how it could be that GHGs are NOT having the effects that all current scientific understanding says they should have. (No skeptic has done either thing.)

10. 2001-2005 mean ∆Tavg above 1951-80 base, °C Temperature increases are nonuniform: higher mid-continent, highest of all in far North. (These are observations, not modeling results.) J. Hansen et al., PNAS 103: 14288-293 (26 Sept 2006)

11. Evaporation & precipitation are increasing NCDC, 2000 Effect is not uniform; most places getting wetter, some getting drier.

12. GLACIERS ARE MELTING

13. Coastal glaciers are retreating Muir Glacier, Alaska, 1941-2004 August 1941 August 2004 NSIDC/WDC for Glaciology, Boulder, compiler. 2002, updated 2006. Online glacier photograph database. Boulder, CO: National Snow and Ice Data Center.

14. is the MELTING OF THE ARCTIC. New predictions Satellite observations Mean IPCC prediction Most likely change (melt) IPCC range Actual observed melting % change in ice cover it has melted nearly80 YEARSahead of when scientists predicted YEAR

16. WEATHER IS BECOMING MORE EXTREME

17. MAJOR FLOODS PER DECADE

18. “ Australia fires spark calls for CLIMATE ACTION ” - Washington Post, March 1, 2006

19. Wildfires by continent & decade from 1950 The trend has been upward everywhere.

20. This works in part through soil moisture Running, Science, 18 August 2006

21. “ Australia suffers worst drought in 1,000 years ” - Guardian UK, Nov 7, 2008

22. “ Burma cyclone death toll rises above 43,000. ” - USA Today, May 15th, 2008

24. SEA LEVELS ARE RISING Three Year Average Satellite Altimetry Sea Level Change (cm) Year

25. Sea-level is rising mm ACIA, 2004 1993-2003 ≈ 35 mm = 3.5 mm/yr; compare 1910-1990 = 1.5±0.5 mm/yr.

26. Further evidence of changing climate As expected in a warming world, observations over recent decades also show… • Evaporation & rainfall are increasing; • Coastal glaciers are retreating; • Mountain glaciers are disappearing; • Permafrost is thawing; • Sea ice is shrinking; • Greenland is melting; • Sea level is rising; • Species are moving.

27. What changes climate? • Changes in: • Sun’s output • Earth’s orbit • Drifting continents • Volcanic eruptions • Greenhouse gases

28. Climate forcing agents in the industrial era. “Effective” forcing accounts for “efficacy” of the forcing mechanism. Source: Hansen et al., JGR, 110, D18104, 2005. Effective climate forcings 1750-2000 Correlating various lines of evidence has reduced uncertainties WARMING Units are watts per square meter alteration in global-average atmospheric radiation flow COOLING

30. Earth’s Atmosphere

31. THE GREENHOUSE EFFECT

32. “Greenhouse effect” Increasing greenhouse gases trap more heat

33. Atmosphere Matters!

34. Greenhouse gases Carbon dioxide Nitrous oxide Methane Water Sulfur hexafluoride

36. CO2 CONCENTRATIONS ARE OFF THE CHARTS Where we’ll be mid-century if we keep this up 550ppm? More? TODAY: 387ppm Parts per Million CO2 EARLY 1900S CO2 in PPM LAST ICE AGE TEMPERATURE Years

37. today: 390ppm CO2

38. Why should we care?

40. OCEANS ARE ACIDIFYING

41. Sea Levels Are RISING

43. Coral reefs are dying

44. impacts LOCAL LIVELIHOODS

45. COP 12 Montreal, Canada 2005 Each year there is a two-week Conference of the Parties (COP) to discuss the terms of the Kyoto Treaty

46. this all began 20 years ago 1988: The IPCC was created to “provide the decision-makers and others interested in climate change with an objective source of information about climate change”

47. Ratified Treaty KYOTO PROTOCOL 1997 Didn’t Ratify Signed, Ratification Pending No Position

48. AND IMPLEMENTING A THOUSAND DIFFERENT SOLUTIONS

49. SOURCES • BBC World Service Poll - http://www.globescan.com/news_archives/bbc_climate/ • Hansen, James, et al. Target Atmospheric CO2: Where Should Humanity Aim? Submitted April 7, 2008. • The IPCC 4th Assessment Report - www.ipcc.ch • Baer, Paul, Tom Athanasiou and Sivan Kartha. "The Right to Develop in a Climate Constrained World: The Greenhouse Development Rights Framework" • The United Nations Framework Convention on Climate Change • NASA - www.nasa.gov • RealClimate.org • Climate Safety - www.climatesafety.org • New Scientist - www.newscientist.com