|USGS Coastal Vulnerability Index for sea level rise for California. Click to enlarge.|
Stating that the longer California delays planning and adapting to coming sea level rise the more expensive and difficult adaptation will be, California Governor Arnold Schwarzenegger issued an Executive Order (S-13-08) directing a set of state agencies to begin those tasks.
Separately, a newly-released report by David Roland-Holst and Fredrich Kahrl at UC Berkeley—California Climate Risk and Response—found that the state has $4 trillion in real estate assets, of which $2.5 trillion are at risk from extreme weather events, sea level rise, and wildfires, with a projected annual price tag of $300 million to $3.9 billion over this century, depending on how warm the world gets.
The report authors note that the most severe costs associated with coastal flooding and sea level rise will not be incurred until the latter third of the century when, depending on scenario, costs will reach $36-257 billion per decade by 2080 and $57-303 billion per decade by 2100. Those estimates do not include any potential value lost to wetland inundation.
The coastal areas at highest risk, the authors note, are concentrated around the state’s major bays, including the Humboldt, San Francisco, and Monterey Bays. Areas around Los Angeles and San Diego are also at very high risk. Many of these are areas with “quite significant commercial and residential real estate assets.”
...as with wildfire adaptation, the best option may come in changing land-use patterns and land development of the coastal areas to insure that most of the future coastal development in California occurs in areas that are not flood prone.—Roland-Holst and Kahrl
The Governor’s Executive Order directs the state agencies to request that the National Academy of Sciences (NAS) convene an independent panel to complete the first California Sea Level Rise Assessment Report and to initiate within 60 days an independent sea level rise science and policy committee made up of state, national and international experts.
Agencies involved in the project include the California Resources Agency; the Department of Water Resources (DWR); the California Coastal Commission; the California Ocean Protection Council (OPC); California State Parks; and the California Energy Commission.
By 31 March 2009, the state is to hold a public workshop to gather policy-relevant information specific to California for use in preparing the Sea Level Rise Assessment Report and to raise state awareness of sea level rise impacts.
The final Sea Level Rise Assessment Report is to be completed as soon as possible but no later than 1 December 2010. The final Sea Level Rise Assessment Report will advise how California should plan for future sea level rise. The report should include:
Relative sea level rise projections specific to California, taking into account issues such as coastal erosion rates, tidal impacts, El Niño and La Niña events, storm surge and land subsidence rates;
The range of uncertainty in selected sea level rise projections;
A synthesis of existing information on projected sea level rise impacts to state infrastructure (such as roads, public facilities and beaches), natural areas, and coastal and marine ecosystems; and
A discussion of future research needs regarding sea level rise for California.
State agencies are to review the NAS assessment every two years or as necessary.
Other components of the order include:
Prior to release of the final Sea Level Rise Assessment Report from the NAS, all state agencies that are planning construction projects in areas vulnerable to future sea level rise are, for planning purposes, to consider a range of sea level rise scenarios for the years 2050 and 2100 in order to assess project vulnerability and, to the extent feasible, reduce expected risks and increase resiliency to sea level rise.
All projects that are underway and/or are programmed for construction funding the next five years, or are routine maintenance projects may, but are not required to, account for these planning guidelines.
Sea level rise estimates should also be used in conjunction with appropriate local information regarding local uplift and subsidence, coastal erosion rates, predicted higher high water levels, storm surge and storm wave data.
A report within 90 days to assess vulnerability of transportation systems to sea level rise that will include provisions for investment critical to safety, maintenance and operational improvements of the system and economy of the state.
By 30 June 2009, the California Resources Agency, through the Climate Action Team, shall coordinate with local, regional, state and federal public and private entities to develop a state Climate Adaptation Strategy.
The strategy is to summarize the best known science on climate change impacts to California, assess California’s vulnerability to the identified impacts and then outline solutions that can be implemented within and across state agencies to promote resiliency.
A water adaptation strategy will be coordinated by DWR with input from the State Water Resources Control Board, an ocean and coastal resources adaptation strategy will be coordinated by the OPC, an infrastructure adaptation strategy will be coordinated by the California Department of Transportation, a biodiversity adaptation strategy will be jointly coordinated by the California Department of Fish and Game and California State Parks, a working landscapes adaptation strategy will be jointly coordinated by the California Department of Forestry and Fire Protection and the California Department of Food and Agriculture, and a public health adaptation strategy will be jointly coordinated by the California Department of Public Health and the California Air Resources Board, all as part of the larger strategy.
By 30 May 2009, OPR, in cooperation with the California Resources Agency, is to provide state land-use planning guidance related to sea level rise and other climate change impacts.
|Rise in sea level in San Francisco Bay since 1900, relative to 1990 level. Click to enlarge. Source: Roland-Holst and Kahrl|
The sea level gauge operating at Fort Point in San Francisco Bay (the country’s longest continuously operating gauge) has recorded a 7-inch rise in sea level over the 20th century. The Intergovernmental Panel on Climate Change (IPCC) has projected that global sea levels will rise by between seven to 23 inches this century; some experts predict even higher rises.
The order notes that California’s water supply and coastal resources, including valuable natural habitat areas, are particularly vulnerable to sea level rise over the next century and could suffer devastating consequences if adaptive measures are not taken.
Further, billions of dollars in state funding for infrastructure and resource management projects are currently being encumbered in areas that are potentially vulnerable to future sea level rise.
Technical Supplement to California Climate Risk and Response