# Presentation: 153686

## Informing Decision Makers of the Potential Impacts of Sea Level Rise in the Coastal Region of New Jersey 

- Michael D. Beevers
- Princeton University and University of Maryland
- Presentation prepared for the U.S. Climate Change Science Program Workshop
- November 15, 2005
- Arlington, VA

## Introduction 

- Sea Level Rise (SLR): significant and growing threat to New Jersey
- Changes in SLR related to fluctuations in global temperature (IPCC, 2001)
- Effects of SLR likely to intensify

- (IPCC, 2001)

## Coastal Resources

- Atlantic coastline - 204 km; Raritan and Delaware Bays – 134 km
- Coastal population ~5.3 million (60% of total)
- Industry: $16 billion tourism; $50 billion maritime; $100 million commercial fishing

## Coastal Resources

- 24 endangered or threatened species
- Atlantic flyway ~1.5 million migratory shorebirds
- World’s largest population of horseshoe crabs

## Methods – SLR Projections

- NJ mean SLR trend = 3.53 mm/yr
- Global-mean SLR trend - 1.0-2.0 mm/yr or a total of 10-20 cm (IPCC, 2001)
- NJ  local component ~2 mm/yr

- NJ Tide-Gauge Data (NOAA, 2004)

## Methods – SLR Projections

- Projected global-mean SLR: 0.09 –
- 	0.88 m over next century
-     (IPCC, 2001)
- Projected NJ relative SLR: 0.31 -
- 	1.10 m (global + local components)
- NJ SLR parameters:
- 0.61 m (2 ft) (50% probability  2100)
- 1.22 m (4 ft) (1% probability  2100)

- Projected global-mean SLR (IPCC, 2001)

-  Applied SLR projections to digital elevation models
-  Limitations: static representation, unable to represent future shorelines

## Coastal Inundation 

- 0.61 m SLR:
- ~170 km2
- (1% land area)
- 1.22 m SLR:
- ~442 km2
- (3% land area)

- Estimated land area susceptible to inundation applying SLR projections

## Coastal Flooding

- Associated with storm events - episodic
- NJ 100-yr flood water level: ~2.90 m
- 100-yr flood water levels exceeded 4 – 20 times more frequently
- Current 100-yr flood water level could become:
- 30-yr flood water level (0.61 m SLR)
- 5-yr flood water level (1.22 m SLR)

- Potential impact of SLR on tidal surge frequency
- and flood levels, Atlantic City, NJ

## Coastal Flooding 

- Episodic flooding
- w/ 0.61 m SLR:
- 1,787 km2 
- 9% land area

- Estimated land area susceptible to flooding applying SLR projections

## Coastal Erosion |  Saline Intrusion

- Future shoreline change rate with SLR: 73 -146 m – high variability (see Zhang et al., 2004)
- Significant coastal erosion

- Increased salinity of surface and groundwater near coastal areas
- Alteration of coastal ecosystems

## Potential Impacts on Socio-economic Systems 

- Developed NJ coastline susceptible to:
- Inundation: ~19.5 – 60 km2
- Flooding: ~269 - 414 km2
- Impacts ~145 km2 previously unaffected developed shoreline
- Communities currently safe from most severe flooding events will be impacted

- Atlantic City, NJ

## Potential Impacts on Natural Systems

- Coastal wetlands susceptible to SLR:
- Inundation: ~15 - 30% of saline marshes
- More frequent episodic flooding
- Coastal wetlands risk inundation if SLR is faster than accretion rate or “squeezed” by development

- Cape May, NJ

## Case Study  - Cape May NWR, Migratory Bird Refuge and Wetlands 

- Globally important bird area (Chipley et al., 2003) ~ 90 km2
- 80% coastal wetlands
- Large concentrations of breeding, migrating, and wintering bird species
- Atlantic flyway
- World’s largest population of horseshoe crabs

## Case Study – Cape May NWR, Migratory Bird Refuge and Wetlands

- Estimated land area susceptible to inundation and episodic flooding applying SLR projections

## Case Study – Cape May NWR, Migratory Bird Refuge and Wetlands

- Inundation: 40 – 50% of bird areas
- Coastal wetland loss  38 – 49%
- Episodic flooding: 76 – 90% of bird areas
- Habitat change and alteration  able to sustain current population levels of coast dependent bird species? Horseshoe crabs??

## Adaptation Opportunities

- Coastal management responses to SLR:
- Defending the existing coastline (structural and non-structural approaches)
-  	 short-term: due to high property value/tourism cost effective
-  	 long-term: elimination of coastal wetlands and high costs
- Allow coastline to naturally migrate inland
- 	 gradual withdrawal of development from coastline (Titus, 1991)

## Adaptation Opportunities

- Coastal land use planning in New Jersey:
- Development in hazardous and sensitive coastal regions
- Current provisions do direct new development away from high hazard areas BUT...in place construction and expansion of existing development remains unaffected
- NJ DEP: success at acquiring susceptible coastal areas

## Adaptation Opportunities

- Political, legal and social challenges:
- Largely unsuccessful defending coastal development permit denials when litigation brought by private parties
- Acquisition of coastal resources  BUT can only protect a minority through acquisition

## Informing Decision Makers

- Restating science in lay language – inadequate
- Dynamic & overlapping decision process:
-  climate, SLR, ecological processes, coastal management, regulations, risk

## Informing Decision Makers

- Decision process: SLR and coastal management
- Routine problem  SOP and repetitive decisions
- Repeated, complex & controversial problems  stakeholder participation model – “open process” (Stern and Fineberg, 1996)

## Informing Decision Makers

- How is risk to SLR contextualized by technical experts, decision-makers, citizens??

- (Slovic, 1987; adapted from Stern and Fineberg, 1996)

## Informing Decision Makers

- Detailed and targeted scientific and technical information
- Decision makers  understand enough to make good decisions
- Stakeholders  understand enough to participate in good decisions
- Address uncertainty  BUT  “don’t wait for certainty in an uncertain world”
- Adaptive management – strategy as hypothesis as well as plan
- Flexibility  social learning  change
- Expansion of decision making cycles – institutional patience
- Make decision makers aware they are experimenting

## Conclusions

- Katrina effect   which “policy window”??

## References

- Chipley, R.M. et al: 2003, *The American Bird Conservancy Guide to the 500 Most Important Bird Areas in the United States*, Random House, New York.
- Intergovernmental Panel on Climate Change (IPCC): 2001, ‘Summary to Policymakers, A report on Working Group of the Intergovernmental Panel on Climate Change’ in *Climate Change 2001, the Scientific Basis*, Cambridge University Press, Cambridge, pp. 1-20.
- National Oceanic and Atmospheric Administration (NOAA): 2004, *Mean Sea Level Trends for Stations in New Jersey*, _[http://coops.nos.noaa.gov/sltrends/sltrends](http://coops.nos.noaa.gov/sltrends/sltrends)_
- New Jersey DEP Bureau of Geographic Information Services: 2004, _[http://www.nj.gov/dep/gis/](http://www.nj.gov/dep/gis/)_
- Slovic, P: 1987, ‘Perception of Risk’, *Science* 236, 280-285.
- Stern, P. and Fineberg, H.V. (eds): 1996, *Understanding Risk, Informing Decisions in Democratic Society*, National Academy Press, Washington DC.
- Titus, J.G.: 1991, ‘Greenhouse Effect and Sea Level Rise, the Cost of Holding Back the Sea’, *Coastal Management* **19**, 171-204.
- Zhang, K. et al: 2004, ‘Global Warming and Coastal Erosion’, *Climatic Change* **64**, 41-58.

## Contact Information

- Michael D. Beevers
- _[mbeevers@gvpt.umd.edu](mailto:mbeevers@gvpt.umd.edu)__ _
- _[mbeevers@Princeton.edu](mailto:mbeevers@Princeton.edu)_