Future sea level rise through 2100 and beyond

Transcription

1 Future sea level rise through 2100 and beyond Emma Stone Uncertain World Summit (Tuesday 20 October 2015) 1

2 Why are we interested in future sea level rise? How certain are we about the worst case scenario at 2100? Living with environmental uncertainty 2

3 ~53 m ~7 m ~3-4 m Figure provided by Gordon Inglis and Catherine Catherine McIntyre 3

4 ~53 m Contributions by 2100: Glaciers (~0.16 m) Thermal Expansion (~0.27 m) ~7 m Land water storage (~0.04 m) Antarctica (~0.04 m) Greenland (~0.12 m) ~3-4 m Ice sheet rapid dynamics (~0.12 m) 4

5 IPCC predictions for future sea level by 2100 IPCC AR5 prediction by 2100: 0.26 to 0.98 m (Business as usual: 0.52 to 0.98 m) 5

6 6

7 IPCC predictions for future sea level by 2100 IPCC AR5 prediction by 2100: 0.26 to 0.98 m (Business as usual: 0.52 to m) Likely range in sea level rise (66%).what about the ~33% sea level change outside of this uncertainty range? 7

8 IPCC predictions for future sea level by 2100 NOT the worst case upper limit IPCC AR5 prediction by 2100: 0.26 to 0.98 m (Business as usual: 0.52 to m) Likely range in sea level rise (66%).what about the ~33% sea level change outside of this uncertainty range? 8

9 IPCC predictions for future sea level by 2100 NOT the worst case upper limit IPCC AR5 prediction by 2100: 0.26 to 0.98 m Low (RCP8.5: probability, 0.52 to high impact m) region Likely range in sea level rise (66%).what about the ~33% sea level rise outside of this uncertainty range? 9

10 Magnitude & rate of ice sheet contributions Regional distribution of sea level rise Current known uncertainties Future emissions scenarios and climate sensitivity Regional changes in storm frequency and intensity 10

11 Thermal Expansion Glaciers Land water 11 Jevrejeva et al. (2014)

12 Thermal Expansion Glaciers Land water Greenland Antarctica Expert Elicitation 12 Jevrejeva et al. (2014)

13 Thermal Expansion Glaciers Land water Greenland Antarctica Fat tail Expert Elicitation 13 Jevrejeva et al. (2014)

14 Thermal Expansion Glaciers Land water Jevrejeva et al. (2014) Greenland Antarctica 14

15 Jevrejeva et al. (2014) Living with environmental uncertainty 15

16 IPCC likely range Jevrejeva et al. (2014) Living with environmental uncertainty 16

17 IPCC likely range 5% probability of sea level exceeding 1.8 m Jevrejeva et al. (2014) Living with environmental uncertainty 17

18 What about beyond 2100? Can the past help us understand future sea level? Foster and Rohling (2013) Living with environmental uncertainty 18

19 +9 m Foster and Rohling (2013) Living with environmental uncertainty 19

20 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? 20

21 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? Bamber and Aspinall (2013) 21

22 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? Bamber and Aspinall (2013) 22

23 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? Bamber and Aspinall (2013) 23

24 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? Bamber and Aspinall (2013) 24

25 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? Bamber and Aspinall (2013) 25

26 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? What about the unknown unknowns? 26

27 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? What about the unknown unknowns? How much will increased understanding of the processes at play reduce the size of the fat tail from ice sheet contributions? 27

28 Final thoughts for discussion Is observed behaviour due to: Ice-sheet weather (short term variability) Ice-sheet climate (a long term trend) Or both? What about the unknown unknowns? How much will increased understanding of the processes at play reduce the size of the fat tail from ice sheet contributions? What do we regard as a reasonable worst case scenario for sea level rise? 28