Climate Change Professor Matthew England Climate and Environmental Dynamics Laboratory

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. 2004 1959 290 190 CO2 Concentration is Rising 2000 1000 1200 1600 1800 1400

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 20th 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]

17. Southern Hemisphere Jet Stream

18. Southern Annular Mode

19. Southern Annular Mode … 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. 5.8 IPCC high and low projection 1.4 Spörer minimum Maunder minimum Dalton minimum 2100 The Past and the Future • Instrumental Data • Proxy Reconstructions • Model Simulations ∆T 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 Year 1500 2000 500 1000

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

30. Annual-mean temperature change predicted for 2070-2100 in IPCC Third Assessment Report models 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.

31. Climate Change simulation to year 2054

32. IPCC-WG1 [2007]

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

35. CONCLUSIONS • 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

36. CONCLUSIONS • 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

37. CONCLUSIONS • 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

38. CONCLUSIONS • 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

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