Regionalizing Sea-level Rise Projections for Urban Planning Bob - - PowerPoint PPT Presentation

DIMACS/CCIADA Workshop on Urban Planning for Climate Events 23 September 2013

Bob Kopp Rutgers University E-mail: robert.kopp@rutgers.edu

Regionalizing Sea-level Rise Projections for Urban Planning

Collaborators: Ken Miller, Ben Horton, Jim Browning, Vladimir Pavlovic (Rutgers); Jerry Mitrovica (Harvard); Andrew Kemp (Tufts) Students and Postdocs: Carling Hay, Eric Morrow (Harvard)

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Past Sea Level and Flooding Future Sea Level and Flooding Coastal Vulnerability Planning for Resilience

The coastal impacts, vulnerability and adaptation knowledge chain

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 Bloustein School of Planning & Public Policy

Earth & Planetary Sciences Geography Environmental Science Center for Advanced Infrastructure & Transportation CCICADA Walton Center for Remote Sensing & Spatial Analysis Jacques Cousteau National Estuarine Research Reserve

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

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N N

Ship Bottom, NJ 2008 (Ken Miller) October 31, 2012

Storm surges take place in a context of sea-level change

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100 yr storm 10 yr storm

Sandy 13.9 ft Donna 10 ft Irene 9.5 ft

• Dec. 93

9.8 ft

sea level rise

50 yr storm Miller; modified after Zervas (2005) Heights in blue relative to MLLW (FEMA standard)

Kemp & Horton (2013) estimates of the contribution

• f historical sea-level rise to flooding at the Battery

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storm tide storm surge tide cumulative sea-level rise cumulative glacio-isostatic adjustment (ICE6G-VM5b; 0.66 mm a-1)

Year (AD) Contribution to Flood Height (m)

1788 1821 1893 1938 1960 1985 2012 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Donna Gloria Sandy

Dominant factors in global sea level rise:

• 1. Thermal Expansion

Meehl et al. (2007)

Compare observed thermal expansion of about 1.0 mm/yr from 1983-2003 (Domingues et al., 2008)

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Dominant factors in global sea level rise:

• II. Glacier and ice sheet melt

Lemke et al. (2007); Bamber et al. (2001); Lythe et al. (2001)

Total Hazard Non-polar glaciers and ice caps 0.26 ± 0.11 m Greenland & Antarctic glaciers and ice caps 0.46 ± 0.17 m Greenland Ice Sheet 7 m West Antarctic Ice Sheet 5 m East Antarctic Ice Sheet 52 m

Maps by P . Fretwell (British Antarctic Survey)

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Road map

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• 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?]

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

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Global Sea Level change is not the same as local sea level change

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• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

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

Yin et al. (2009)

20° N 40° N 60° N 100° W 60° W 20° W 0.1 ¬0.1 ¬0.3 ¬0.5 –0.7 –0.9 ¬1.1 ¬1.3

a

(m)

SSH, 1992-2002

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Global Sea Level change is not the same as local sea level change

Projected dynamic sea level anomalies from changes in the Atlantic Meridional Overturning Circulation in A1B in 2091-2100, relative to 1981-2000

20° N 40° N 60° N 100° W 60° W 20° W 0.4 0.3 0.2 0.1 ¬0.1 ¬0.2 ¬0.3 ¬0.4

c

(m)

Yin et al. (2009) 14

• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

Global Sea Level change is not the same as local sea level change

ME

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• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

Global Sea Level change is not the same as local sea level change

ME-MI MI

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Not to scale!

Farrell & Clark (1976), after Woodward (1888)

• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

Mitrovica et al. (2011)

WAIS ~1.1x West Antarctica Greenland

Gravitational-Elastic-Rotational Fingerprints of Greenland and WAIS melting, per meter GSL rise

Global Sea Level change is not the same as local sea level change

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• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

Global Sea Level change is not the same as local sea level change

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Global predictions of the present-day rate of change of relative sea level (mm yrx1; positive denotes sea-level rise). (a) is the prediction

Sea-level rise due to GIA (mm/y) Mitrovica et al., 2001

• Ocean dynamic effects
• Mass redistribution effects: Gravitational, elastic and rotational
• Natural and groundwater withdrawal-related sediment compaction
• Long term: Isostasy and tectonics

Geoid trends inferred from GRACE, 2002-2009

Chambers et al. (2010) 19

What sort of regional variations do we see?

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What do we actually see?

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1900 1950 2000 −100 100 200 300 400 500 600 mm NEW YORK 1900 1950 2000 −100 100 200 300 400 500 600 mm ATLANTIC CITY

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

Local long-term ~linear sea-level anomaly rate (mm/y)

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260 265 270 275 280 285 290 295 300 25 30 35 40 45 50 Long−term linear sea level anomaly rate (mm/y) 0.5 1 1.5 2 2.5 3 3.5 4 225 230 235 240 245 250 255 260 265 25 30 35 40 45 50 Long−term linear sea level anomaly rate (mm/y) −2 −1.5 −1 −0.5 0.5 1 1.5 2

after Kopp (2013)

complicated GIA + compact. Erosion + compaction

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LETTERS

PUBLISHED ONLINE: 24 JUNE 2012 | DOI: 10.1038/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

1880 1900 1920 1940 1960 1980 2000 2020 28 30 32 34 36 38 40 42 44 46 48 Time Latitude DAYTONA B MAYPORT FORT PULA SPRINGMAI PORTSMOUT SOLOMON’S ATLANTIC SANDY HOO NEWPORT SEAVEY IS BAR HARBO NORTH SYD ARGENTIA smooth non−linear regional sea level anomaly rate (mm/y)

a

−1.5 −1 −0.5 0.5 1 1.5 1900 1920 1940 1960 1980 2000 −40 −30 −20 −10 10 20 30

b

New York City AMO − 7 y −NAO − 2 y −GSNW − 0 y mm

Really? Yes, but it’s too early to tell if it goes beyond natural variability (but it will likely, eventually)...

Kopp (2013)

p=.03 p=.14 p=.10

How can we incorporate these into projections?

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Scenario-based localization example: SLR scenarios for NYC and New Jersey

25 after Miller et al. (in rev.)

Global effects Regional effects Local eff. 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 5 3 3 2

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• 1

4 3 13 22 25 2030 low 2 3 1 1 2

• 1

3 2 8 15 18 2030 high 11 4 4 6 8

• 1

5 4 21 30 33 2030 higher 11 4 4 6 8

• 1

5 4 24 36 40 2050 best 10 6 8 2 10

• 4

7 5 25 38 43 2050 low 4 5 2 1 3

• 1

5 4 16 27 32 2050 high 19 7 10 9 13

• 3

9 6 39 52 57 2050 higher 19 7 10 9 13

• 3

9 6 45 62 68 2100 best 24 14 27 8 20

• 13

13 10 73 93 103 2100 low 10 13 4 2 5

• 3

9 8 40 64 74 2100 high 46 19 35 33 25

• 11

17 12 117 139 149 2100 higher 46 19 35 33 25

• 11

17 12 133 164 176 2100 collapse 55 37 54 100 35

• 6

17 12 246 292 304 Totals

Probabilistic localization example

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using Bamber & Aspinall (2013) for ice sheets: 30 cm (10-103 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 cm 95% 50% 33% 5% 1% GSL 47 77 89 151 233 Honolulu 50 87 102 181 288 NYC 67 101 115 186 286 Atlantic City 77 112 125 196 298

0.5 1 1.5 2 2.5 0.2 0.4 0.6 0.8 1 Sea−level rise, 2000−2100 (m) Exceedance probability GSL Honolulu NYC Atlantic City

Seaside Heights, NJ

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Maps available from http://slrviewer.rutgers.edu/ and http://sealevel.climatecentral.org/

1 foot (likely by ~2040) 3 feet (likely by 2090s) 6 feet (~5% chance by 2100)

Influence of moderate SLR on historical flood levels

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Miller et al. (in rev.)

Take-aways

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• 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
• n 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 2100.

• 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.