Why do we care about Antarctic climate? A talk given by Andrew Russell at the north-west local centre of the Royal Meteorological Society on 29th March 2011

1. Why do we care about Antarctic climate? Dr Andrew Russell Brunel University [email_address] @dr_andy_russell @Antarctic_news

3. Image: BAS

27. What’s black and white and red all over?

28. Robert McCabe

29. The Antarctic “ozone hole”

31. Antarctic temperature trends

32. Is Antarctica warming, cooling or do we not really know?

33. Is Antarctica warming, cooling or do we not really know? Yes

34. Turner et al. (2005) “Antarctic climate change during the last 50 years” International Journal of Climatology 25 , 279-294.

35. Image: United States Historical Climatology Network

36. USA: 1000 observing stations, some go back to late 1800s Antarctica: 55 stations, very few go back to before 1957 Image: NASA

37. Can we be clever?

38. Steig et al. (2009) “Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year” Nature 457 , 459-462.

39. O’Donnell et al. (2011). Improved methods for PCA-based reconstructions: case study using the Steig et al. (2009) Antarctic temperature reconstruction Journal of Climate , in press

40. Antarctic sea ice NSIDC Zhang (2004)

42. Antarctic ice cores

43. Bubbles and gases * V BAS

44. What period do ice cores cover?

45. Petit et al. (1999)

46. Tilt Eccentricity Precession Wikipedia IPCC

47. EPICA (2004) Nature

48. Phew! Wikipedia

49. But CO2 lags temperature in these records so how does this explain the warming?

50. Idea “borrowed” from Richard Alley. An analogy.. Initial credit card debt of £1000 Pay off £5 per month 20% APR interest Can an initial forcing be amplified by some other mechanism?

51. Idea “borrowed” from Richard Alley.

53. My work on Antarctic weather and climate

55. Changes in the Southern Annular Mode IPCC (2007) IPCC (2007)

56. The Southern Annular Mode http://www.niwa.co.nz NIWA

57. The Southern Annular Mode http://www.niwa.co.nz

58. Negative SAM index

59. Positive SAM index

60. Changes in the Southern Annular Mode Gillett and Thompson (2003) Science Thompson and Solomon (2002) Science IPCC (2007) Marshall (2003)

62. Russell et al. (2008) ASL

63. Russell & McGregor (2010) Climatic Change Russell et al. (2004) Tellus A

70. Russell et al. (2006) GRL

72. http://nsidc.org/iceshelves/larsenb2002/animation.html

73. Southern Annular Mode BAS

74. Why you should be a bit concerned about Antarctic climate

75. IPCC (2007) Bindschadler et al. (1998) EoS “ Ice sheet models indicate that this would be offset by tens of percent by increased ice discharge, but still give a negative contribution to sea level, of –0.8 m by 3000 in one simulation with Antarctic warming of about 4.5°C ” Antarctic ice sheet

76. Rignot and Thomas (2002)

77. Peter Boyer Under the Antarctic ice sheet

78. Oppenheimer (1998) Nature Under the Antarctic ice sheet

79. Shepherd et al. (2001) Science Vaughan et al. (2006) GRL Pine Island Glacier

80. "Parts of the Antarctic ice sheet that rest on bedrock below sea level have begun to discharge ice fast enough to make a significant contribution to sea level rise. Understanding the reason for this change is urgent in order to be able to predict how much ice may ultimately be discharged and over what timescale. Current computer models do not include the effect of liquid water on ice sheet sliding and flow, and so provide only conservative estimates of future behaviour." Chris Rapley, former director of BAS

81. 84m sea level rise! Benfield Hazard Research Centre. This plot is silly. Worse case scenario - complete WAIS collapse - would result in 4-6m of sea level rise.

82. Why you should be very interested in Antarctic climate

83. Ted Scambos

84. Manchester Science Festival 22-30 October 2011