1. Climate Change Professor Matthew England Climate and Environmental Dynamics Laboratory School of Mathematics, Faculty of Science The University of New South Wales

2. Causes of climate change

3. CO 2 Concentration is Rising 190 290 1959 2004 10001200 1400 16001800 2000

5. Why is Venus hotter than Mercury? Mercury temperature = ~85  C Venus temperature = 500  C Answer - The Greenhouse Effect!

7. NH air temperatures since 1000 A.D.

9. Global 20 th Century Temperature Trends

11. Is the Antarctic changing? … observations Larsson-B Ice Shelf Collapse 31 January to 7 March 2002 http://nsidc.org/iceshelves/larsenb2002/animation.html

12. Twentieth Century Land-Ice Changes Davis et al., Vaughan; Science, 2005

13. Melting of the Greenland Ice-sheet

14. Australian temperature trend, 1950 – present day

15. Australian rainfall trend, 1950 – present day

16. Total annual inflow into Perth Dams IPCC-WG2 [2007]

18. Southern Annular Mode

19. … trend due to ozone delpletion & greenhouse gas increases

20. How much will our climate change in the future? … models

22. Climate Modelling Governing equations Forcing conditions Initial conditions Model output

23. Models of the ocean and atmosphere Solve governing equations over a discrete grid Use (sparse) observations in forcing functions Integrate solutions forward in time Assess simulation vs. observed fields

28. 1000 20001500 500 Year The Past and the Future  Instrumental Data  Proxy Reconstructions  Model Simulations 2100 5.8 IPCC high and low projection 1.4 Spörer minimum Maunder minimum Dalton minimum 0 0.2 -0.2 -0.4 -0.6 0.4 ∆T -0.8

29. Rahmstorf et al. We are currently tracking at the very high end of emission scenarios and temperature projections

30. Annual mean change in temperature (colour shading) and its range (isolines) (Unit: °C) for the SRES scenario A2, showing the period 2071 to 2100 relative to the period 1961 to 1990. Annual-mean temperature change predicted for 2070-2100 in IPCC Third Assessment Report models

31. Climate Change simulation to year 2054

32. IPCC-WG1 [2007]

34. Figure 1. Model Simulation of Trend in Hurricanes (from Knutson et al, 2004)Knutson et al, 2004 CONTROL 2050

35. The planet has seen substantial climate change in the past century These changes cannot be explained by known modes of natural variability (i.e., solar cycles, …) A manifestation of climate change can easily be found in air temperatures, rainfall, ocean properties, land-ice, sea-level, winds, storm tracks, … These changes will accelerate over the coming decades/century unless we adopt aggressive response strategies CONCLUSIONS

36. The planet has seen substantial climate change in the past century These changes cannot be explained by known modes of natural variability (i.e., solar cycles, …) A manifestation of climate change can easily be found in air temperatures, rainfall, ocean properties, land-ice, sea-level, winds, and storm tracks These changes will accelerate over the coming decades/century unless we adopt aggressive response strategies CONCLUSIONS

37. The planet has seen substantial climate change in the past century These changes cannot be explained by known modes of natural variability (i.e., solar cycles, …) A manifestation of climate change can easily be found in air temperatures, rainfall, ocean properties, land-ice, sea-level, winds, and storm tracks These changes will accelerate over the coming decades/century unless we adopt aggressive response strategies CONCLUSIONS

38. The planet has seen substantial climate change in the past century These changes cannot be explained by known modes of natural variability (i.e., solar cycles, …) A manifestation of climate change can easily be found in air temperatures, rainfall, ocean properties, land-ice, sea-level, winds, and storm tracks These changes will accelerate over the coming decades/century unless we adopt aggressive response strategies CONCLUSIONS

39. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

40. Physical oceanography and climate science The study of the physics, properties, and dynamics of the oceans and coupled climate system

41. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

42. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer- review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

43. Intergovernmental Panel on Climate Change (IPCC) http://www.ipcc.ch

44. Intergovernmental Panel on Climate Change (IPCC)

45. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

46. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

47. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

48. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

49. Some issues re. climate science Climate scientists are well aware of natural variability Climate scientists have no “conflict-of-interest” Climate science must undergo rigorous peer-review Climate scientists should not prescribe policy Inexpert debate - unlike any other science Opportunities for innovation and economic growth We have succeeded before: CFC’s, … Climate scientists are your best source of information for climate science

50. Climate Change Professor Matthew England Climate and Environmental Dynamics Laboratory School of Mathematics, Faculty of Science The University of New South Wales

51. Milankovitch Forcing : Variation in Incident Solar Radiation Due to Natural Variations in Earth’s Orbit Eccentricity: 100,000 Year Cycle Obliquity: 41,000 Year Cycle Precession: 26,000 Year Cycle

52. Simulation: Global Warming Scenario (Rahmstorf & Ganopolski, Clim. Change 1999)

53. Antarctic Circumpolar Current

54. Southern Ocean water-masses

55. The Greenhouse fingerprint