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About me
- Planning consultant
– CASE Consultants International
- IPCC FAR – 2007
– Hired by NOAA/UNCA – Co-author of APA PAS report
- Co-author of APA Climate Change Policy Guide
Sea level rise implications for eastern NC Scott Shuford, AICP - - PowerPoint PPT Presentation
Sea level rise implications for eastern NC Scott Shuford, AICP - - PowerPoint PPT Presentation
Sea level rise implications for eastern NC Scott Shuford, AICP NCBIWA April 23, 2018 About me Planning consultant CASE Consultants International IPCC FAR 2007 Hired by NOAA/UNCA Co-author of APA PAS report
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SLIDE 3
Causes of sea level rise
- Thermal expansion
- Melting of land-based ice (glaciers, ice sheets)
- Subsidence
- Changes to ocean currents
SLIDE 4
Sea level rise in NC
48.5 cm or ~19 inches
4
Federal Department of Transportation
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5
Sea level rise in NC
Graphics courtesy of The Nature Conservancy
2 feet
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6
One meter (~40”) of SLR
Sea level rise in NC
SLIDE 7
NOAA’s SLR Viewer at 6 feet of SLR
Sea level rise in NC – 6 feet
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Historic sea levels
London Geological Society Note the stable SL over the last 4,000 years in the graph above
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Historic sea levels
USGS figure from handout brochure
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Historic sea levels
This figure shows the shoreline 20,000 years ago prior to a 125 meter rise to current SL. Note that the shoreline was at the continental shelf
- ff the NC coast.
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USGS
Historic sea levels
KEY Orangeburg Scarp City of Fayetteville
This figure shows the shoreline during the Pliocene Era 3M years ago when global temperatures were 2-3 degrees Celsius above current temps. The SL then was 30 m higher than today. The Paris Accord is trying to hold global temperature rise below 2 degrees Celsius.
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SLR is more than just inundation
- Storm surge magnification
- Salt water intrusion
- Disruption of ocean outflows (e.g., rivers,
drainage ditches)
- Infrastructure degradation
- Insurance – availability and affordability
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Adaptive responses
- Evaluate “risk”
– “Risk” is your level of exposure to an event relative to the likelihood of that event happening – For SLR, exposure is significantly related to elevation above sea level and to time – SLR is extremely likely and its impacts will increase
- ver time but its extent is not certain
- Respond accordingly to the level of risk, based
- n client/community tolerance for risk and
best information available
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Adaptive responses
Greater exposure Less exposure
Project is long-term Project is short-term Project is more costly Project is less costly Project is lower elevation Project is higher elevation
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Adaptive responses
The US Naval Yards and the City of Norfolk have major exposure to SLR. DOD
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Adaptive responses
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The Confederation Bridge in Canada was built with anticipation of a meter of SLR. The subway grate riser protects subways from street flooding while providing amenities like seating and a bike rack.
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Decision-making
- Beach nourishment project – 5-10 life span
- Seawall – 50 year life span
- Paved road – 20-30 year life span
- Rail line – 50+ year life span
- Sewage treatment plant – 70 year life span
- Major bridge – 100 year life span
Project decision making should take into account how much SLR will occur over the life span of the particular project.
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Planning ahead
- Retreat
- Fortification
- Abandonment
- Migration
– Industries (tourism, farming, etc.) – Residents
Planning for the future must include large scale actions to address SLR depending on the projected extent of potential impacts.
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Conclusions
- SLR will significantly reshape coastal NC
regardless of its ultimate extent
- It will be necessary to evaluate adaptive
responses using risk-based analysis
- Difficult choices will be required; these
choices should be informed by the best available data, but there will always be an element of uncertainty
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