Vicki Arroyo BRWIV

7/29/2019 Vicki Arroyo BRWIV

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Decisionmaking Under Uncertainty

Vicki Arroyo

Executive Director

Georgetown Climate Center


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One Reaction to Uncertainty: Airport Security


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I know certainty freaks you guys out,

but its 100 [percent]


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Views of climate change impacts


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Key Uncertainties in the Climate Models


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Uncertain Futures


8/31Associated PressAssociated Press


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Urban Heat Tool Kit

Audience Local Planners

Heat

adaptation

methods

Green roofs

Cool roofs Cool pavements

Urban forestry

Analysis

of options

By adaptation method

By authority

By type of land use By tradeoffs


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Sea-Level Rise Uncertainties


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High6.6 feet

Low**0.7 feet

Adapting to Uncertain

Sea-Level Rise


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State Adaptation Plans


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Adaptation Planning


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Old Twin Span

New Twin Span21 feet higher

Elevating Interstate 10

Michael DeMocker/Times-Picayune


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Audience State and Local Planners

Coastaladaptation

methods

Accommodate Protect

Retreat

Analysis

of options

By adaptation method

By authority

By type of land use By tradeoffs

Sea-Level Rise Tool Kit


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Sea level rise policy approaches

Adapted from image from Integration and Application Network, University of Maryland Center for Environmental Science (ian.umces.edu/symbols)

Protect Zone

Accommodate ZoneConservation Zone


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Uncertainties in Projecting Sea-Level Rise

Most states using IPCC models that

failed to account for ice sheet melt

resulting in conservative estimates

Shorelines are constantly in flux due to

natural processes Models classify flooding by depth only

Difficulty Downscaling


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Skewed uncertainty = Elevated Risk

Probabi

lity

Increasing Impacts Severity

Idealized view ofscientific uncertainty

Uncertainty basedon climate sensitivity

risky fat tail

Risk & Uncertainty


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How Scientists Deal With Uncertainty

Quantitative

Qualitative


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Strategies for building

resilience in the face ofuncertainty Adaptive management

Resilient design Precautionary regulations Robust decision-making Insurance Redundancy


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How Do Engineers Deal with Uncertainty?

Base FloodElevation

Wave runupstorm surge

Engineeringmargin of safety

Uncertainty(e.g. rapid ice sheet melt)

LEVEEDESIGN(historic

conditions)

ADAPTIVEDESIGN

Adapted from Dessai & VanDer Slutjs 2007


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How Do Courts Deal with Uncertainty?

Substantive Due Process: Land Use Regulations constitutional if they have a

rational basis supported by policy rationale

Agency Decision-making

Agency decisions are valid unless arbitraryor capricious


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Climate science is not too uncertain to

guide agency decisions Imperfect models are entitled todeference

Precautionary regulation is permitted

How Courts Deal with

Scientific Uncertainty


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Beyond a reasonable doubt

Clearing and convincing evidence

Substantial and credible

evidence

Preponderance of theevidence

Probable cause

Rational basis

Arbitrary and

capricious

Level of certaintyneeded to regulatefor climate impacts


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Designing for Sea Level Rise

Sherman Creek Waterfront Esplanade Proposal

WXY Architecture and Urban Design

City of New York

MoMA Rising CurrentsNew Urban Grounddlandstudio and ARO City of New York


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An example of adaptive design:

Treasure Island, San Francisco


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Dedicated openspace

Setbacks

Elevated structures

Clusteredhigh-densitydevelopment

Plans for flood protection +funding


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Adaptation Reduces Vulnerability and Increases Resilience


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Landing Page Features


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For more information:www.georgetownclimate.orgwww.adaptationclearinghouse.org
http://www.georgetownclimate.org/http://www.adaptationclearinghouse.org/http://www.adaptationclearinghouse.org/http://www.georgetownclimate.org/

Documents

Vicki Arroyo BRWIV