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FIGURE 5.10 Committee’s projected sea-level rise for California, Oregon, and Washington compared with global projections. The dots are the projected values and the colored bars are the ranges. Washington and Oregon = coastal areas north of Cape Mendocino; California = coastal areas south of Cape Mendocino.

RARE EXTREME EVENTS

Extreme events can raise sea level much faster than projected above. The rapid rise in sea level could be temporary, as in the case of a severe storm, or permanent, as in the case of a great subduction zone earthquake. The potential contribution of such extreme events to future sea-level rise is described below.

Extreme Sea Level

In the first 3 months of 1983, the west coast of the United States experienced a sequence of strong storms, with the coincidence of El Niño conditions, high astronomical tides, and large waves producing record sea levels along virtually the entire coast (see “Changes in Ocean Circulation” in Chapter 4). Damage was extensive (e.g., Figure 5.11), with losses totaling $215 million (in 2010 dollars; Griggs et al., 2005). Some models predict that such extreme events will become more common and that heightened sea level will persist longer as sea level rises, increasing the potential for damage (Cayan et al., 2008; Cloern et al., 2011).

Cloern et al. (2011) used a GCM forced by the IPCC (2000) B1 emission scenario to assess possible climate change impacts in the San Francisco Bay and delta. As part of the analysis, they used a local sea-level model, introduced by Cayan et al. (2008), to investi-



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