Regionalizing Sea-level Rise Projections for Urban Planning

Transcription

1 Regionalizing Sea-level Rise Projections for Urban Planning Bob Kopp Rutgers University Collaborators: Ken Miller, Ben Horton, Jim Browning, Vladimir Pavlovic (Rutgers); Jerry Mitrovica (Harvard); Andrew Kemp (Tufts) Students and Postdocs: Carling Hay, Eric Morrow (Harvard) DIMACS/CCIADA Workshop on Urban Planning for Climate Events 23 September 2013

2 The coastal impacts, vulnerability and adaptation knowledge chain Past Sea Level and Flooding Future Sea Level and Flooding Coastal Vulnerability Planning for Resilience 2

3 Coastal Climate Change Research for Resilience Past Sea Level and Flooding Future Sea Level and Flooding Coastal Vulnerability Planning for Resilience Institute of Marine & Coastal Sciences Earth & Planetary Sciences Geography Environmental Science Bloustein School of Planning & Public Policy Center for Advanced Infrastructure & Transportation Walton Center for Remote Sensing & Spatial Analysis Jacques Cousteau National Estuarine Research Reserve CCICADA

4 Coastal Climate Change Research for Resilience Past Sea Level and Flooding Future Sea Level and Flooding Coastal Vulnerability Planning for Resilience This talk Lathrop Greenberg Andrews

5 Ship Bottom, NJ N N 2008 (Ken Miller) October 31,

6 Storm surges take place in a context of sea-level change Sandy 13.9 ft 100 yr storm sea level rise Donna 10 ft Dec ft Irene 9.5 ft 50 yr storm 10 yr storm Miller; modified after Zervas (2005) 6 Heights in blue relative to MLLW (FEMA standard)

7 Kemp & Horton (2013) estimates of the contribution of historical sea-level rise to flooding at the Battery Contribution to Flood Height (m) tide storm surge cumulative sea-level rise storm tide cumulative glacio-isostatic adjustment (ICE6G-VM5b; 0.66 mm a -1 ) Donna Gloria Sandy Year (AD) 7

8 Dominant factors in global sea level rise: 1. Thermal Expansion Compare observed thermal expansion of about 1.0 mm/yr from (Domingues et al., 2008) 8 Meehl et al. (2007)

9 Dominant factors in global sea level rise: II. Glacier and ice sheet melt Total Hazard Non-polar glaciers and ice caps Greenland & Antarctic glaciers and ice caps Greenland Ice Sheet West Antarctic Ice Sheet East Antarctic Ice Sheet 0.26 ± 0.11 m 0.46 ± 0.17 m 7 m 5 m 52 m Maps by P. Fretwell (British Antarctic Survey) 9 Lemke et al. (2007); Bamber et al. (2001); Lythe et al. (2001)

10 Road map Why does regional sea level differ from global sea level? What sort of regional sea level variations do we see? How can we incorporate these into projections? [How can understanding past sea level help us move beyond informed expert judgment for projecting ice sheet behavior?] 10

11 Why does regional sea level differ from global mean sea level? 11

12 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics 12

13 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics a 0.1 b 60 N N N (m) 40 N N 20 N 100 W 60 W 20 W 80 W c SSH, d Yin et al. (2009)

14 40 N Global Sea Level change N 0.9 is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics N 20 N 100 W 60 W 20 W c 60 N 40 N (m) d Projected dynamic sea level anomalies 60 N from changes in the Atlantic Meridional Overturning Circulation in A1B in , 40 N relative to N 20 N 100 W 60 W 20 W 8 14 Yin et al. (2009)

15 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics ME 15

16 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics MI ME-MI Not to scale! Farrell & Clark (1976), after Woodward (1888) 16

17 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics Gravitational-Elastic-Rotational Fingerprints of Greenland and WAIS melting, per meter GSL rise West Antarctica Greenland WAIS ~1.1x Mitrovica et al. (2011) 17

18 Global Sea Level change is not the same as local sea level change Ocean dynamic effects Mass redistribution effects: Gravitational, elastic and rotational Natural and groundwater withdrawal-related sediment compaction Long term: Isostasy and tectonics predictions of the present-day rate of change of relative sea level (mm yr x1 ; positive denotes sea-level rise). (a) is the Sea-level rise due to GIA (mm/y) 18 Mitrovica et al., 2001

19 Geoid trends inferred from GRACE, Chambers et al. (2010)

20 What sort of regional variations do we see? 20

21 What do we actually see? 600 NEW YORK 600 ATLANTIC CITY mm mm Purple: Church & White (2011) GSL Blue: Tide gauge data Green: Long-term sea-level signal ~1.3 mm/y GIA An additional ~1 mm/y on the shore Interannual variability of ~10 cm 21

22 Local long-term ~linear sea-level anomaly rate (mm/y) Long term linear sea level anomaly rate (mm/y) Long term linear sea level anomaly rate (mm/y) complicated GIA + compact Erosion + compaction after Kopp (2013) 22

23 LETTERS PUBLISHED ONLINE: 24 JUNE 2012 DOI: /NCLIMATE1597 Hotspot of accelerated sea-level rise on the Atlantic coast of North America Asbury H. Sallenger Jr*, Kara S. Doran and Peter A. Howd Really? Yes, but it s too early to tell if it goes beyond natural variability (but it will likely, eventually)... Latitude smooth non linear regional sea level anomaly rate (mm/y) a ARGENTIA NORTH SYD BAR HARBO SEAVEY IS NEWPORT SANDY HOO ATLANTIC SOLOMON S PORTSMOUT SPRINGMAI mm b New York City Time FORT PULA MAYPORT DAYTONA B AMO 7 y NAO 2 y GSNW 0 y p=.03 p=.14 p=.10 Kopp (2013) 23

24 How can we incorporate these into projections? 24

25 Scenario-based localization example: SLR scenarios for NYC and New Jersey Global effects Regional effects Local eff. Totals Thermal Glaciers GIS AIS Ocean dynamics Mass redist. GIA Coastal subsidence Global NYC Shore cm cm cm cm cm cm cm cm cm cm cm 2030 best low high higher best low high higher best low high higher collapse after Miller et al. (in rev.) 25

26 Probabilistic localization example Exceedance probability GSL Honolulu NYC Atlantic City Sea level rise, (m) cm 95% 50% 33% 5% 1% GSL Honolulu NYC Atlantic City using Bamber & Aspinall (2013) for ice sheets: 30 cm ( cm, 90% range) Glaciers from Radic et al. (2013): 20 cm (10-30 cm) Thermal expansion from NRC (2012): 24 cm (10-46 cm) Dynamic sea level from Yin et al. (2009) GIA and subsidence from Kopp (2013) Fingerprints from Mitrovica 26

27 Seaside Heights, NJ 1 foot 3 feet 6 feet (likely by ~2040) (likely by 2090s) (~5% chance by 2100) Maps available from and 27

28 Influence of moderate SLR on historical flood levels 28 Miller et al. (in rev.)

29 Take-aways Regional sea-level rise differs from global mean sea-level rise due to a variety processes; we must understand these processes in order to generate sea-level rise projections that are maximally useful for local decisionmakers. Our current best estimates project >1 foot more sea-level rise on the Jersey shore than the global average by 2100, leading to a most-likely projection of ~3.5 on the Shore by 2100, and about a 5% probability of sea-level rise in excess of 6 by These estimates are ultimately informed expert judgment, though informed by modeling output and the historical record. Better pre-historical records, combined with better physical and statistical models, can allow us to advance further. 29