Sea Level Rise &Implication for Harbors and Marinas

Ronald M. Noble

Looking Into a Warmer Future…

MSLR by 2100 Assuming ΔT < 4° C(Nicholls, et al. 2011 Phil. Trans. Roy. Soc.)

Greenland (+21 ft) and Antarctica (+200 ft) melting will become largest contributor to global MSL rise

Global ≠ Regional MSLR 1992-2009

Fast Rise

No Rise

Global MSLRnot evenly distributed

dynamical effects!

Global MSLR 3.3 mm/yr or 33 cm/cy

Is MSL rise acceleration imminent on west coast?

http://www.aviso.oceanobs.com/

“Reg

ime

Shift

”

Reve

rsal

?

Bromirski, Miller, Flick, Auad, 2011. Dynamical suppression of sea level rise along the Pacific coast of North America: Indications for imminent acceleration, Jour. Geophys. Res. 116(C07005)

Bromirski, Miller, Flick, 2012, North Pacific Sea Level Trends, Eos Trans. AGU, 93(27), 249-256.

Historical Mean Sea Level Trend: San Francisco

Source: NOAA Website

Historical Mean Sea Level Trend: Los Angeles

Source: NOAA Website

“Prediction is very difficult,

especially if it's about the future.”

- Niels ‘Yogi Berra’ Bohr

Global Sea Level Change Prediction (by 2100)

Source: USACE EC 1165-2-212

USACE SLR Guidance: EC 1165-2-212 (2011)

Three SLR scenarios: “Low” SLR rate: using the historical rate of SLR “Intermediate” SLR rate: using modified NRC Curve I “High” SLR rate: using modified NRC Curve III

CO-CAT includes state entities:− Business, Transportation and Housing Agency− Coastal Commission− Dept of Fish and Game− Dept of Parks and Recreation− Dept of Public Health− Dept of Toxic Substances Control− Dept of Transportation− Dept of Water Resources− Environmental Protection Agency− Governor’s Office of Planning and Research− Natural Resources Agency− Ocean Protection Council− Ocean Science Trust− San Francisco BCDC− State Coastal Conservancy− State Lands Commission− State Water Resources Control Board

California Sea-Level Rise Guidance Document

California Climate Action Team (CO-CAT) developed a SLR Guidance based upon NRC 2012 report SLR.

NRC (2012) SLR Report

California Sea-Level Rise Guidance Document

CO-CAT reached agreement on the following policy recommendations for SLR

Time PeriodNorth of

Cape MendocinoSouth of

Cape Mendocino

2000 - 2030-4 to 23 cm

(-0.13 to 0.75 ft)4 to 30 cm

(0.13 to 0.98 ft)

2000 – 2050-3 to 48 cm

(-0.1 to 1.57 ft)12 to 61 cm

(0.39 to 2.0 ft)

2000 – 210010 to 143 cm(0.3 to 4.69 ft)

42 to 167 cm(1.38 to 5.48 ft)

CCC (2013) Draft Sea-Level Rise Policy Guidance

SLR Projects between USACE and CA State

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

Sea

Leve

l Ris

e fr

om 2

000

(ft)

Year

USACE Low SLR Scenario

USACE Intermediate SLR Scenrio (Modified NRC-I)

USACE High SLR Scenario (Modified NRC-III)

Modified NRC-II

CO-CAT SLR (South of Cape Mendocino)

Cardiff State Beach, 1998

Stinson Beach, 1998

MSL is 20 feet lower!

wave

^

Wave-Driven Runup & Overtopping = Damage

Both private and public infrastructure is and will be at risk!

Waves, Storm Surge & High TidesFlooding & Erosion

December 1982

January 1983

Mission Beach 2010Hs 4 m

Hs 3 m

Beaches and infrastructure are “tuned” to current extremes of ~3m (10 ft) MSL (Bill O’Reilly cartoon)

Extra 0.5-2 m!

“Tuned”

MSLR

SF Bay Area Potentially Exposed to SLR

Over 1 in 6 chance sea level rise + storm surge + tide will overtop + 6 ft by 2100

Implication of SLR: Marina del Rey, California

Src: http://sealevel.climatecentral.org/

Over 1 in 6 chance sea level rise + storm surge + tide will overtop +7 ft by 2100

Implication of SLR: San Francisco, California

Src: http://sealevel.climatecentral.org/

Impact of SLR on Yosemite Slough Wetlands Restoration

Impact of SLR on Yosemite Slough Wetlands Restoration

Impact of SLR on Yosemite Slough Wetlands Restoration

Impact of SLR on Yosemite Slough Wetlands Restoration

Impact of SLR on Yosemite Slough Wetlands Restoration

MSL is 20 feet lower!

Return-Period ‘Creep’

100-yr Maximum Water Level (+5.2 ft MSL) in 2000 becomes 10-yr event in 2017, 1-yr event in 2048, and monthly in 2083

Projections based on MSL rise “central” value +3 ft (2000-2100)

NRC (2012)

Waves, Storm Surge & High TidesFlooding & Erosion

December 1982

January 1983

Mission Beach 2010Hs 4 m

Hs 3 m

Cardiff State Beach, 1998

Stinson Beach, 1998

MSL is 20 feet lower!

wave

^

Wave-Driven Runup & Overtopping = Damage

Both private and public infrastructure is and will be at risk!

Wet

Dry

Mild -but- Variable Climate

• Decades drought

• Decades wet

• Extremes111⁰ - 26 Sep 19633.2” rain - 5 Apr 192625” rain 1940-4126” rain 1883-84

• CA Four “Seasons”QuakeDroughtFireFlood

Dry?

San Francisco Annual Mean Sea Level

60

70

80

90

100

110

1840 1860 1880 1900 1920 1940 1960 1980 2000

cm (M

LLW

)

Sea Level Rise Rates Vary

Regional MSLR rates depend on large-scale atmospheric conditions over North Pacific Ocean

El Niño

-5.4 cm/cy

18 cm/cy

-0.7 cm/cy