The Sea Level Projections of USACE EC 1165-2-211 in Context

Kris Esterson & Sergey GorlachevEverglades Project Joint Venture

GEER 2010Greater Everglades Ecosystem RestorationThe Greater Everglades: A Living Laboratory of ChangeJuly 14, 2010

OVERVIEW OF PRESENTATION

How are SLR projections are developed using USACE guidance (EC 1165-2-211)?

EC projections in the context of:

•Latest scientific literature on sea level rise•Other projections in use in the region•Related climate change effects•Role in decision support

HOW ARE THE PROJECTIONS DEVELOPED?

Naples Tide Station Record

Record exceeds 40yr minimum

High Rate Contribution (standard worldwide)

Intermediate Rate Contribution (standard worldwide)

EC’s projections connected to orthometric and tidal datums

LATEST DEVELOPMENTS IN THE

SCIENTIFIC LITERATURE

Responding to Changes in Sea Level:

Engineering Implications

NRC, 1987

The source of the EC’s

High and Intermediate

Curves

Sea Level Projections from the Literature

1.43m

0.18m

USACE EC 1165-2-211For Naples, FL

From Rahmstorf (2010)

OTHER PROJECTION METHODOLOGIES

2050 2100

0 ft

6 ft

1.09’ (34cm) for 2100 (Yellow Book, 1999)

3 ft

1.7’ by 2100 (CGM 16, 2004)

2030

?

?

2 ft

1 ft

4 ft

5 ft

2000

SFRPC 10% Worst Case

SFRPC 50% Moderate Case

SFRPC 90% Least Case

SLR Projections & Planning Standards for South Florida

>1.5’ for ~2059 (Miami-Dade., 2009)

0.5’ SFWMD Sensitivity Test (Trimble, 1998)

0.48’ (15cm) for 2050 (Yellow Book, 1999)

EC 11

65-2

-211

High

EC 1165-2-211 Intermediate

>3-5’ for ~2100 (Miami-Dade., 2009)

0.8’ by 2050 (CGM 16, 2004)

2.1” to 1’ for 2030 (Broward Co., 2009)

EC 1165-2-211 Historic

NRC 2nd Biennial Review (2008) “not much more than 3 feet”

?

GREENHOUSE GAS EMISSIONS SCENARIOS

Drivers Stressors Impacts

Greenhouse Gas Emissions

CO2Ocean

Acidification

Sea Level Rise

Hurricane Intensity

Precipitation Change

Increased Global

Temperature

Impacts to Natural and

Built Environments

Typical SLR Impact Assessment

Drivers Stressors Impacts

Greenhouse Gas Emissions

CO2Ocean

Acidification

Sea Level Rise

Hurricane Intensity

Precipitation Change

Increased Global

Temperature

Impacts to Natural and

Built Environments

Exploring Causation

What GHG emissions scenario would produce this SLR?

Actual Emissions vs IPCC SRES Scenarios

Raupach et al. 2007, PNAS, updated; Le Quéré et al. 2009, Nature Geoscience; International Monetary Fund 2009

1990 1995 2000 2005 2010 2015

Fo

ssil

Fu

el E

mis

sio

n (

GtC

y-1)

5

6

7

8

9

10

A1B

A1FI

A1T

A2

B1

B2

Carbon Dioxide Information Analysis Center

International Energy Agency

EC “High” SLR Projection

EC “Intermediate”

EC “Historic”

Source: Global Carbon Project

RELATED EFFECTS OF CLIMATE CHANGE

What other climate change effects are related to this SLR scenario?

Drivers Stressors Impacts

Greenhouse Gas Emissions

CO2Ocean

Acidification

Sea Level Rise

Hurricane Intensity

Precipitation Change

Increased Global

Temperature

Impacts to Natural and

Built Environments

What Climate Effects are Associated with a “High” SLR Scenario?

Accelerated SLR cannot occur in a vacuum

UTILITY AND LIMITATIONS IN DECISION SUPPORT

EC’s Projections & Decision Support

Scenarios- End of academic process and start of decision support.

Scenarios- Three scenarios with equal chance of occurrence.

Not probabilistic- No “most likely” projection. Not predictions/forecasts- They bound rather than hide

uncertainty. Multiple futures rather than single line forecasts.

No information on “surprises”- Smooth projections don’t describe potential surprises such as leaps in the rate of rise

EC’s Projections & Decision Support

Not probabilistic- Makes traditional risk assessment unclear. Calculation of traditional risk requires probabilities.

Not predictions/forecasts- Makes cost-benefit analysis difficult as benefits may vary depending on SLR scenario. Complicates engineering design.

No information on “surprises”- Management strategies (AM, SBP) based on SLR projections may not fully incorporate the range of potential outcomes.

Questions?