Sea Level Rise
Framing the Issue
California has been among the most aggressive U.S. states in its policies to reduce CO2 emissions. Its policies and strategies have been developed and expanded over several administrations led by governors from different parties, reflecting a broad political consensus on their priority. At the sub-state level, cities and regions in California have taken on the role of planning for the anticipated rise in sea levels, which will occur at some level whether or not C02 reduction goals are met.
Scientific estimates suggest that the magnitude of sea-level ride (SLR) in California could be at least six inches by 2030 and as much as seven feet by 2100. The impact of that rise will be magnified at times by exceptionally high tides (”king tides”) that regularly occur and by major storm events. While the exact magnitude of sea-level rise and its timing is still unknown, current research suggests that the most widespread physical impact will take the form of increased coastal flooding from sea and waves, through both permanent inundation and episodic events aggravated by storms. Consequent impacts include the erosion of coastal cliffs and rising groundwater levels which can cause flooding away from the immediate coastline. One recent study has suggested that flooding from emergent groundwater in the San Francisco Bay Area could impact a larger area across the region than wave-induced flooding.