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Sea Level Rise


Sea levels may rise twice as much by the end of this century than was previously predicted. That's according to an announcement last week by the U.N. Intergovernmental Panel on Climate Change. Also last week, the Oakland-based Pacific Institute released a study finding that hundreds of thousands of people and billions of dollars of California infrastructure and property will be at risk if ocean levels rise 55 inches. What should we do to prepare?
— "Oceans rising," Forum, KQED radio, March 16, 2009 (Listen to the program)

Latest from the Team

The Climate Action Team is meeting with pertinent staff from various divisions to engage in a series of dialogues regarding scenarios for sea level rises, and changes in temperatures and precipitations. A draft summary helps you to think about impacts and adaptation in your area and a list of questions helps to facilitate the dialogue. After each dialogue, key outcomes are summarized.

News Articles about SCVWD's Work on Sea Level Rise

Rising Seas, Federal Inaction and Donald Trump Turn Climate Change into a Local Issue, Metro/San Jose Inside, Dec 8, 2016

Little Hoover Commission Explores Local Response to Climate Change, Association of California Water Agencies, Oct 27, 2016

Palo Alto considers bracing now for sea level rise, Palo Alto Daily News, Jul 14, 2016

More articles about SCVWD's work on sea level rise

Tools Available to Date (updated March 2015)

The latest Army Corps of Engineers regulation stipulated that "potential relative sea level change must be considered in every USACE coastal activity as far inland as the extent of estimated tidal influence" (December 2013). The Climate Action Team has compiled the following for District staff's use:

  1. Our Coast, Our Future - "A collaborative, user-driven project focused on providing San Francisco Bay Area coastal resource and land use managers and planners locally relevant, online maps and tools to help understand, visualize, and anticipate vulnerabilities to sea level rise and storms within the bay and on the outer coast from Half Moon Bay to Bodega Bay."

  2. Cal-Adapt - Tools to visualize sea level rise for local areas. (May 2011 updates)

  3. Digital Shoreline Analysis System - "Computer software that computes rate-of-change statistics from multiple historic shoreline positions residing in a geographic information system. (NOAA Digital Coast and U.S. Geological Survey)

  4. FEMA Map Service Center - Download flood maps from the Federal Emergency Management Agency

  5. More sea-level rise maps:

  6. Global Climate Change: NASA's Eyes on the Earth. Latest statistics on climate change, including a Sea Level Viewer.

  7. Climate Wizard. This site presents precipitation and temperature scenarios, displayed geographically, through the year 2100. (From the Nature Conservancy, University of Washington, and University of Southern Mississippi)

  8. Incorporating Sea Level Change in Civil Works Programs: This Regulation (ER 1100-2-8162) provides United States Army Corps of Engineers (USACE) guidance for incorporating the direct and indirect physical effects of projected future sea level change across the project life cycle in managing, planning, engineering, designing, constructing, operating, and maintaining USACE projects and systems of projects. (Dec. 31. 2013).

  9. Risk and Uncertainty Analysis. This site provides software that supports risk and uncertainty analysis in hydraulic engineering systems used by the San Francisquito Creek Flood Damage & Reduction Ecosystem Restoration project. The Army Corps of Engineers currently uses the @Risk computer program to perform Monte Carlo statistical analysis for stage-damage estimates for various flood frequency events. This analysis is a used to account for a lack of complete knowledge concerning the phenomena and processes inherent in problem definition and resolution. Uncertainties in hydraulic engineering system design can be divided into four basic categories:

    1. hydrologic or design discharge determination;
    2. hydraulic or accuracy in geometric and Manning's roughness variables;
    3. structural or likelihood of levee failure, and
    4. economic or stage-damage relationships
    Reliability analysis typically includes:
    1. identify and analyze the uncertainties of contributing factors to the system;
    2. combine the uncertainties of the stochastic factors to determine the overall reliability of the structure (hydraulic utility).

  10. FEMA and Sea Level Rise. The Federal Emergency Management Administration's (FEMA) 1991 study, Projected Impact of Relative Sea Level Rise on the National Flood Insurance Program, determined that if sea levels rise by 1 foot between 1990 and 2100, flood damages on NFIP-insured property would increase 36-58 percent. If sea levels rise by 3 feet, the increase would be 102-200 percent. In June 2009, FEMA Launches Effort to Measure Impact of Climate Change on Flood Insurance. FEMA's report, Hurricane Ike in Texas and Louisiana (2009), has a chapter, "Planning for a Sustainable Coast", that incorporates sea level rise. Designing for Flood Levels above the BFE (2006) is a publication issued after Hurricane Katrina that recommends designing for flood levels above the base flood elevation, in part because those levels do not account for sea level rise and more frequent severe storms.

    FEMA has also developed various training courses: for example, Catastrophe Readiness and Response, deals with slow-motion catastrophes including sea level rise and drought; another course on coastal hazards management deals with sea level rise.

Latest Policy Directives or Discussions (updated August 2015)

Sea-Level Rise Policy Guidance

Description: "Interpretive guidelines for addressing sea level rise in local coastal programs and coastal development permits." Adopted Aug. 12, 2015.
Source: California Coastal Commission
Publication Date: August 12, 2015

Governing California Through Climate Change: Executive Summary

Description: The commission recommends that "the Governor should work with key state agencies . . . to clarify the impact of sea level rise on California's Common Law Public Trust Doctrine. A collective dialogue should seek ways to create a legal framework in advance of crisis and prevent litigation and instability as a rising ocean begins to condemn private property on the Pacific coastline." Full report
Source: Little Hoover Commission
Publication Date: July 10, 2014

Incorporating Sea Level Change in Civil Works Programs

Description: Army Corps' policy, Dec. 2013, regulation no. ER 1100-2-8162 stipulated that "potential relative sea level change must be considered in every USACE coastal activity as far inland as the extent of estimated tidal influence."
Source: United States. Army Corps of Engineers
Publication Date: December 31, 2013

California Ocean Protection Council: Update to the Sea Level Rise Guidance Document

Description: Updated guidance "to help state agencies incorporate future sea-level rise impacts into planning decisions, but has now been updated to include the best current science." Includes a table summarizing sea level models for the years 2030-2100 north and south of Cape Mendocino.
Source: California Ocean Protection Council
Publication Date: March 15, 2013

California Climate Adaptation Strategy

Description: State of California's comprehensive plan to guide adaptation to climate change, becoming the first state to develop such a strategy.
Source: California's Natural Resources Agency
Publication Date: Aug. 3, 2009

BCDC Bay Plan

Description: The San Francisco Bay Conservation and Development Commission (BCDC) is making some changes to its Bay Plan, taking climate change into account. SCVWD's Ann Draper has made some comments on their proposals.
Source: San Francisco Bay Conservation and Development Commission
Publication Date: Jun 2, 2009

Adapting to Rising Tides

Description: Fact sheets on efforts by local governments in the Bay Area to adapt to sea level rise. A "community of practice" site is available for state and local officials to exchange adaptation experiences.
Source: United States. National Oceanic and Atmospheric Administration

Projects/Programs of Interest

Latest Reports

All reports on sea level rise

Sea Level Rise Scenarios

The table below is sorted from higher estimates to lower ones. Mouse over estimates to read longer descriptions of each projection. Printer-friendly version

Estimate (inches) Agency Report (Year) Source of Information Note
2050 2100
low high low high
    7.9 78.8 NOAA Global Sea Level Rise Scenarios for the United States National Climate Assessment (2012) Synthesis  
    31.5 78.8 n/a Pfeffer, W. T., et al., Kinetic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise (2008) Original research  
      70.9 n/a Jevrejeva, S., et al. Upper limit for sea level projections by 2100 (2014) Original research  
    35.5 63.0 Arctic Monitoring and Assessment Programme Snow, Water, Ice and Permafrost in the Arctic (2011) Synthesis  
    18.0 60.0 BCDC Sea Level Rise: Predications and Implications for SF Bay, p. 15 (1988) National Research Council. Responding to Changes in Sea Level (1987)  
    19.7 59.1 n/a Rohling, E. J. High rates of sea-level rise during the last interglacial period (2007) Original research  
5.9 23.6 19.7 59.1 US Army Corps of Engineers Planning for Sea Level Rise: U.S. Army Corps of Engineers Policy (2002) National Research Council. Responding to Changes in Sea Level (1987) This is the basis for the current Shoreline study
    19.7 59.1 US Army Corps of Engineers Incorporating Sea Level Change in Civil Works Programs (2013) IPCC 2007; NRC 1987 Note: Includes instructions for calculating local sea-level rise
    40.2 57.1 California Climate Change Center/Pacific Institute Heberger, M., et al. The Impacts of Sea-Level Rise on the California Coast (2009) Based on Cayan, et al., 2006; Rahmstorf 2007; Cayan, et al. 2009  
6.9 19.0 19.8 55.2 National Academy of Sciences Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future (2012) Synthesis  
11.8 17.7 23.6 55.2 California Climate Change Center Cayan, D., et al., Climate Change Scenarios and Sea Level Rise Estimates for the California 2008 Climate Change Scenarios Assessment (2009) Rahmstorf 2007; other sources  
    19.7 55.2 n/a Rahmstorf, S., A Semi-Empirical Approach to Projecting Future Sea-Level Rise (2007) Original research  
3.2 16.2 7.9 55.2 DWR Technical Memorandum: Delta Risk Management Strategy. . . Topical Area: Climate Change, p. 13 (2008) IPCC 2001, Rahmstorf 2007, extrapolation  
      55.2 USGS Knowles, N. Projecting Vulnerability to Inundation Due to Sea Level Rise in the San Francisco Bay and Delta (2008) Community Climate System Model using A2 emission scenario  
    19.7 55.2 CALFED Bay-Delta Program Sea Level Rise and Delta Planning (Independent Science Board) (2007) Recent empirical models after IPCC 2007  
    7.1 55.2 USGS Report of workshop in Menlo Park (2008) IPCC 2007; Rahmstorf 2007  
      55.0 Delta Vision Blue Ribbon Task Force Letter to Governor, March 24, 2008 (2008) CalFed Independent Science Board Assumption for strategic plan; asks that Governor issue an executive order with estimates of sea level rise for 2050 and 2100
  16.0   55.0 BCDC Living with a Rising Bay: Vulnerability and Adaptation in San Francisco Bay and on its Shoreline (2011) Cayan, et al. 2009; Rahmstorf 2007  
      54.8 California Climate Change Center Knowles, N. Potential Inundation Due to Rising Sea Levels in the San Francisco Bay Region (2009) Cayan, et al. 2009; Cayan, et al. 2008  
    9.4 51.6 n/a Kopp, R. E., et al., Temperature-driven global sea-level variability in the Common Era (2016) Original research  
    35.5 51.2 n/a Grinsted, A., et al., Reconstructing sea level from paleo and projected temperatures 200 to 2100AD (2009) Original research  
    22.5 43.3 n/a Jevrejeva, S., et al. Sea level projections to AD2500 with a new generation of climate change scenarios (2012) Original research  
  16.5   39.4 BCDC Analysis of a Tidal Barrage at the Golden Gate (2007)    
    18.5 39.4 n/a Horton, et al., Sea level rise projections for current generation CGCMs . . ., Geophysical Research Letters 35 (2008) Original research  
    3.9 39.4 BCDC BCDC Climate Change Planning Project (2007) IPCC and Climate Action Team "Sea level rise models indicate that a 30 cm (11.8 inch) rise in sea level would shift the 100-year storm surge-induced flood event to once every 10 years."
    19.7 39.4 International Scientific Congress on Climate Change Rising sea levels set to have major impacts around the world (2009) Research presented at the conference  
    5.9 37.4 USGS National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the US Pacific Coast (2000) IPCC 1995 Old report
  12.0   36.0 Calif. Coastal Commission Overview of Sea Level Rise and Some Implications. . . , p. 12 (2001) EPA, Titus and Narayanan 1995  
    5.1 35.1 Calif. Climate Change Ctr. Scenarios of Climate Change in California: An Overview, p. 10 (2006) Cayan, et al.  
    22.0 35.0 Calif. Ocean Protection Council Resolution on Climate Change (2007) Our Changing Climate  
    22.0 35.0 Calif. Climate Change Ctr. Our Changing Climate, p. 12-13 (2006)    
    3.6 34.8 DWR Progress on Incorporating Climate Change. . . (2006) Based on IPCC 2001  
    4.0 33.0 Governor's Climate Action Team Governor's Climate Action Team Report (2006) Based on Cayan, et al., 2006  
    2.8 32.3 n/a Siddall, M., et al. Constraints on future sea-level rise from past sea-level change (2009) Original research  
    7.9 31.5 USGS Projecting Inundation Due to Sea Level Rise in the SF Bay and Delta (2006) Knowles (USGS)  
    7.1 31.1 US EPA Future Sea Level Changes (2007) IPCC 2007  
2.4 12.6 3.9 28.4 Calif. Climate Change Ctr. Projecting Future Sea Level, p. 5 (2006) Cayan, et al. Data on waves and storm surges, too
    4.3 28.4 n/a Cayan, D., et al., Climate Change Projections of Sea Level Extremes Along the California Coast, Climatic Change 87 (suppl. 1) (2008) Original research  
      24.0 State of Maine Wetlands and Climate Change webcast, May 13, 3008 (2008)    
    7.1 23.2 IPCC Report of Working Group 1: Summary for Policymakers, p. 13 (2007)   Does not include ice flows, which could increase the upper number by 10-20 cm (4-8 in.). See
    7.1 23.2 IPCC Technical Paper on Climate Change and Water, p. 37 (2008)    
      18.9 USGS Coastal Vulnerability Assessment of GGNRA to Seal-Level Rise (2005) IPCC 2001  
    13.4 15.0 NOAA National Marine Fisheries Viability Criteria for Steelhead of S. Calif., p. 20 (2007) Raper and Braithwaite, 2006  
    11.0 13.4 n/a Church, J. and N. White. A 20th century acceleration in global sea-level rise (2006) Original research  

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Created and maintained by Bob Teeter, District Librarian; organized by Sarah Young

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