The Rising Tide in the Northeast
The Rising Tide in the Northeast: the impact of climate change on coastal flooding and possible adaptation strategies EBC 3rd Annual Ocean Management Conference July 11, 2008 Ellen M. Douglas, PE, PG, PhD University of Massachusetts – Boston
Confronting Climate Change in the Northeast
New findings of the Northeast Climate Impacts Assessment
NECIA A collaboration between UCS and > 50 independent experts from institutions such as:
Colby College
University of Southern Maine Vermont Center for EcoStudies
Natl. Center for Atmospheric Research Texas Tech University University of Illinois – Urbana-Champaign
Cornell University
University of Massachusetts Wesleyan University
University of Waterloo, Canada Princeton University
Columbia University & CUNY
Bigelow Laboratory for Ocean Sciences
University of New Hampshire Harvard University, Tufts University, Wellesley College, & University of MA Boston Woods Hole Oceanographic Institution & Marine Biological Laboratory
IPCC AR4 (2007) “Warming of earth is now unequivocal” – Global sea level rise (SLR) is accelerating: • 1.8 mm/yr average 1961-2003 • 3.1 mm/yr average 1993-2003
– Arctic sea ice decreased 2.7% / decade since 1978 – Greenland and Antarctic Ice Sheets are thinning – Mountain glaciers receding at unprecedented rates
IPCC AR4 (2007) Sea level rise under warming is inevitable. Thermal expansion would continue for many centuries after GHG concentrations have stabilized, for any of the stabilization levels assessed.
Further warming depends on our emissions choices HIGHER A1FI
LOWER B1 Source: IPCC 2001 Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
temperature change ( F)
o
12 10 8 6
observations higher emissions lower emissions
4 2 0 The result of today’s emissions choices
-2 -4 1900
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Unavoidable warming
1950
2000
2050
2100
Projected Rise in Global Sea Level 2005 - 2100
1961-2003: ~1.8 mm/year (IPCC)
Projected Rise in Global Sea Level 2005 - 2100
1961-2003: ~1.8 mm/year (IPCC)* 1993-2003: ~3.1 mm/year (IPCC)*
12.2
*Data prior to 1993 are from tide gauges and after 1993 are from satellite altimetry
Norbert Psuty
Jerry and Marcy Monkman
• More frequent flooding • More coastal erosion • Wetland inundation and loss Michael Dwyer
Coastal Flooding NECIA Coastal Flooding Team: Paul Kirshen, Research Professor, Tufts University Ellen Douglas, Chris Watson, Allen Gontz, Yong Tian, Jawon Lee, UMass Boston
Dr. Norbert P. Psuty
Coastal Flooding Analysis (Kirshen et al, 2007) • Look at historic water levels at tide gages with long record length – Boston, Woods Hole, New London, NYC, Atlantic City…and now Lewes, DE
• Estimate frequency of historic extreme coastal flooding • Add in projected SLR due to climate change scenarios • Compare today’s 100-year flood elevation with future 100-year flood elevations
Defining Sea Level Rise
Tide Gauge
Vertical Land Movement Woodworth, 2001
‘Relative SLR’
‘Eustatic SLR’
Observed sea level rise
Local and Relative Sea Level • Example: Boston, MA – Relative SLR: 2.65 mm/yr (NOAA)
– Eustatic SLR: 1.6 mm/yr (IPCC) – Local SLR: 2.65-1.6 = 1.05 mm/yr (Subsidence)
Processing the Tide Gage Data
Processing the Tide Gage Data
Model Error
Processing the Tide Gage Data
~27 hour storm surge
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Predicted Elevation: -0.77 m NAVD
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Observed Elevation: +0.24 m NAVD Predicted Elevation: -0.77 m NAVD
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Maximum Combined Impact: ~2.0 m NAVD
Observed Elevation: +0.24 m NAVD Predicted Elevation: -0.77 m NAVD
Impact of SLR on the 100-year coastal flood • What is the 100-year flood? – The flood that is expected, OVER THE LONG-TERM, once every 100 years OR – The flood that has a 1% chance of occurring in any year.
Based on probability not prediction
Coastal Flooding Frequency
Woodworth, 2001
Impact of Sea Level Change
100 10 1
Woodworth, 2001
Boston Coastal Flooding Elevation at MHHW (meters NAVD)
4.5
4.0
3.5
3.0
2005 2050 (B1 lo) 2100 (B1 lo) 2050 (A1fi hi) 2100 (A1fi hi)
2.5
2.0 1
10
100
Recurrence Interval (years) Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
1000
Changing frequency of the current 100-year flood
Boston: The Future 100-Year Flood under the Higher-Emissions Scenario
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Boston: The Future 100-Year Flood under the Higher-Emissions Scenario
Edward Giardina
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Preparing for adaptation Some changes are now unavoidable.
Ocean City, NJ Source: http://marine.rutgers.edu/geomorph/oceancityfill.jpg
CLIMB Climate’s Long-Term Impacts on Metro Boston Paul Kirshen, Tufts University (http://www.tufts.edu/tie/climb/) ***Paper by Kirshen, Knee and Ruth, soon to be published in Climatic Change***
Adaptation responses to SLR • Protection: manage hazard using “hard” structures (sea walls) or “soft” measures (beach nourishment). • Accommodation: humans and hazard coexist through “floodproofing” strategies. • Retreat: humans move out of hazardprone areas.
CLIMB Zones: 1 = South Coastal Urban 2 = North Coastal Urban 3 = North Coastal Suburban 4 = South Coastal Suburban 5 = Developed Suburbs 6 = Developing Suburbs South 7 = Developing Suburbs North 32 towns, 110,000 hectares, 1.2 million people (US Census, 2000) Well over half the coastline is hardened (Knee, 2002)
Contemporary Hazard exposure (land use within 500-year floodplain)
(11%)
Year 2000 land use from MassGIS
0.6 m SLR, single event RIO = $19,993 BYWO = $9,400 Green = $5,806 Retreat = $17,155
Retreat Improved BYWO Zoning Adaptation Costs
RIO RIO Damage Costs
Green Improved Zoning Damage Costs
RIO = ride it out (no action); BYWO = build yourCLIMB way out Source: Study
0.6 m SLR, three events RIO = $44,190 $19,993 BYWO = $13,815 $9,400 Green = $12,276 $5,806 Retreat = $17,503 $17,155 RIO RIO RIO Damage Costs
Retreat Retreat Improved BYWO Zoning Adaptation Costs
BYWO
Green Green Improved Zoning Damage Costs
RIO = ride it out (no action); BYWO = build yourCLIMB way out Source: Study
Overall findings • Present flood management strategy, no SLR (only subsidence): $6-9 billion • Range of scenarios and adaptation strategies: up to $94 billion • Advantageous to use expensive structural protection in highly developed areas; more “green” strategies in less developed areas. • Green approaches are cost-effective, “no regrets” and environmentally benign • Regardless of the climate change scenario, taking no action (RIO) was the worst response.
There are limits to adaptation
Northeast U.S. Emissions: Significant on a Global Scale
Note: U.S. emissions include the Northeast
AP Photo/Michael Dwyer
Tony Tremblay
Source: Emissions data for 2001 from Energy Information Administration (EIA), International energy annual (2003), and EIA, Emissions of greenhouse gases in the United States (2004).
Available for download at: http://www.climatechoices.org For more information contact: [email protected]
Thank you!
Confronting Climate Change in the Northeast
New findings of the Northeast Climate Impacts Assessment
NECIA A collaboration between UCS and > 50 independent experts from institutions such as:
Colby College
University of Southern Maine Vermont Center for EcoStudies
Natl. Center for Atmospheric Research Texas Tech University University of Illinois – Urbana-Champaign
Cornell University
University of Massachusetts Wesleyan University
University of Waterloo, Canada Princeton University
Columbia University & CUNY
Bigelow Laboratory for Ocean Sciences
University of New Hampshire Harvard University, Tufts University, Wellesley College, & University of MA Boston Woods Hole Oceanographic Institution & Marine Biological Laboratory
IPCC AR4 (2007) “Warming of earth is now unequivocal” – Global sea level rise (SLR) is accelerating: • 1.8 mm/yr average 1961-2003 • 3.1 mm/yr average 1993-2003
– Arctic sea ice decreased 2.7% / decade since 1978 – Greenland and Antarctic Ice Sheets are thinning – Mountain glaciers receding at unprecedented rates
IPCC AR4 (2007) Sea level rise under warming is inevitable. Thermal expansion would continue for many centuries after GHG concentrations have stabilized, for any of the stabilization levels assessed.
Further warming depends on our emissions choices HIGHER A1FI
LOWER B1 Source: IPCC 2001 Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
temperature change ( F)
o
12 10 8 6
observations higher emissions lower emissions
4 2 0 The result of today’s emissions choices
-2 -4 1900
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Unavoidable warming
1950
2000
2050
2100
Projected Rise in Global Sea Level 2005 - 2100
1961-2003: ~1.8 mm/year (IPCC)
Projected Rise in Global Sea Level 2005 - 2100
1961-2003: ~1.8 mm/year (IPCC)* 1993-2003: ~3.1 mm/year (IPCC)*
12.2
*Data prior to 1993 are from tide gauges and after 1993 are from satellite altimetry
Norbert Psuty
Jerry and Marcy Monkman
• More frequent flooding • More coastal erosion • Wetland inundation and loss Michael Dwyer
Coastal Flooding NECIA Coastal Flooding Team: Paul Kirshen, Research Professor, Tufts University Ellen Douglas, Chris Watson, Allen Gontz, Yong Tian, Jawon Lee, UMass Boston
Dr. Norbert P. Psuty
Coastal Flooding Analysis (Kirshen et al, 2007) • Look at historic water levels at tide gages with long record length – Boston, Woods Hole, New London, NYC, Atlantic City…and now Lewes, DE
• Estimate frequency of historic extreme coastal flooding • Add in projected SLR due to climate change scenarios • Compare today’s 100-year flood elevation with future 100-year flood elevations
Defining Sea Level Rise
Tide Gauge
Vertical Land Movement Woodworth, 2001
‘Relative SLR’
‘Eustatic SLR’
Observed sea level rise
Local and Relative Sea Level • Example: Boston, MA – Relative SLR: 2.65 mm/yr (NOAA)
– Eustatic SLR: 1.6 mm/yr (IPCC) – Local SLR: 2.65-1.6 = 1.05 mm/yr (Subsidence)
Processing the Tide Gage Data
Processing the Tide Gage Data
Model Error
Processing the Tide Gage Data
~27 hour storm surge
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Predicted Elevation: -0.77 m NAVD
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Observed Elevation: +0.24 m NAVD Predicted Elevation: -0.77 m NAVD
Processing the Tide Gage Data
Maximum Surge: +1.01 m
Maximum Combined Impact: ~2.0 m NAVD
Observed Elevation: +0.24 m NAVD Predicted Elevation: -0.77 m NAVD
Impact of SLR on the 100-year coastal flood • What is the 100-year flood? – The flood that is expected, OVER THE LONG-TERM, once every 100 years OR – The flood that has a 1% chance of occurring in any year.
Based on probability not prediction
Coastal Flooding Frequency
Woodworth, 2001
Impact of Sea Level Change
100 10 1
Woodworth, 2001
Boston Coastal Flooding Elevation at MHHW (meters NAVD)
4.5
4.0
3.5
3.0
2005 2050 (B1 lo) 2100 (B1 lo) 2050 (A1fi hi) 2100 (A1fi hi)
2.5
2.0 1
10
100
Recurrence Interval (years) Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
1000
Changing frequency of the current 100-year flood
Boston: The Future 100-Year Flood under the Higher-Emissions Scenario
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Boston: The Future 100-Year Flood under the Higher-Emissions Scenario
Edward Giardina
Source: NECIA/UCS, 2007 (see: www.climatechoices.org/ne/)
Preparing for adaptation Some changes are now unavoidable.
Ocean City, NJ Source: http://marine.rutgers.edu/geomorph/oceancityfill.jpg
CLIMB Climate’s Long-Term Impacts on Metro Boston Paul Kirshen, Tufts University (http://www.tufts.edu/tie/climb/) ***Paper by Kirshen, Knee and Ruth, soon to be published in Climatic Change***
Adaptation responses to SLR • Protection: manage hazard using “hard” structures (sea walls) or “soft” measures (beach nourishment). • Accommodation: humans and hazard coexist through “floodproofing” strategies. • Retreat: humans move out of hazardprone areas.
CLIMB Zones: 1 = South Coastal Urban 2 = North Coastal Urban 3 = North Coastal Suburban 4 = South Coastal Suburban 5 = Developed Suburbs 6 = Developing Suburbs South 7 = Developing Suburbs North 32 towns, 110,000 hectares, 1.2 million people (US Census, 2000) Well over half the coastline is hardened (Knee, 2002)
Contemporary Hazard exposure (land use within 500-year floodplain)
(11%)
Year 2000 land use from MassGIS
0.6 m SLR, single event RIO = $19,993 BYWO = $9,400 Green = $5,806 Retreat = $17,155
Retreat Improved BYWO Zoning Adaptation Costs
RIO RIO Damage Costs
Green Improved Zoning Damage Costs
RIO = ride it out (no action); BYWO = build yourCLIMB way out Source: Study
0.6 m SLR, three events RIO = $44,190 $19,993 BYWO = $13,815 $9,400 Green = $12,276 $5,806 Retreat = $17,503 $17,155 RIO RIO RIO Damage Costs
Retreat Retreat Improved BYWO Zoning Adaptation Costs
BYWO
Green Green Improved Zoning Damage Costs
RIO = ride it out (no action); BYWO = build yourCLIMB way out Source: Study
Overall findings • Present flood management strategy, no SLR (only subsidence): $6-9 billion • Range of scenarios and adaptation strategies: up to $94 billion • Advantageous to use expensive structural protection in highly developed areas; more “green” strategies in less developed areas. • Green approaches are cost-effective, “no regrets” and environmentally benign • Regardless of the climate change scenario, taking no action (RIO) was the worst response.
There are limits to adaptation
Northeast U.S. Emissions: Significant on a Global Scale
Note: U.S. emissions include the Northeast
AP Photo/Michael Dwyer
Tony Tremblay
Source: Emissions data for 2001 from Energy Information Administration (EIA), International energy annual (2003), and EIA, Emissions of greenhouse gases in the United States (2004).
Available for download at: http://www.climatechoices.org For more information contact: [email protected]
Thank you!
