Iconic coast threatened as rising seas ‘drown’ beaches
Leave a CommentThe state is preparing at multiple levels, though many of the steps are advisory only. The OPC, along with the California Energy Commission and Gov. Jerry Brown’s (D) Office of Planning and Research, are formulating guidance for state and local officials, based on that sea-level rise report received in April. It’s an update to a 2013 analysis, incorporating newer science. The guidance expected early next year will be nonbinding.
The state’s 2014 Safeguarding California report, which is also undergoing an update, contains climate adaptation strategies in several categories, including sea-level rise. It’s limited to recommending “current and needed actions state government should take to build climate change resiliency.”
….If West Antarctica’s sheet melts quickly, it would wallop California with greater sea-level rise than the world average, the OPC report said. That’s due to a kind of gravitational effect to ocean currents and the way the Earth rotates, Fricker said. Three feet of sea-level rise coming from Antarctica would mean it’s 4 feet higher in California, she said.
Groundwater near the surface also threatens California beach cities, said Barnard with USGS. As sea levels climb, “that water table’s going to keep rising.”
Low-lying areas near the beach, where the water table is close to the surface, will flood during high tide. It’s what’s happening now in Miami, he said. Areas of Southern California most likely to be hit include parts of Huntington Beach, Newport Beach and Seal Beach in Orange County, and Mission Beach and Del Mar in San Diego.
If the groundwater table rises 2 to 4 feet, Barnard said, “those are going to be areas that are effectively going to be turned into swamps. Even though you might have a wall protecting the water from coming over the top of the beach, there’s a lot of areas that are going to be vulnerable to this groundwater inundation.”
…California beaches bring in big money. The ocean and coast contributed $44.2 billion to the state’s gross domestic product and more than 500,000 jobs in 2013, the latest year available, the state said in its climate adaptation plan, Safeguarding California.
To replenish eroding beaches, many cities and counties have spent many millions of dollars on sand replenishment. That solution might not work long term, Cavalieri said. “It’s going to become more and more expensive,” she said, “and it’s not clear whether there’s enough sand. You have to have more and more sand. Where would it come from?”
Right now, it’s often dredged from harbors, she said. There are ecological impacts, she added, such as the need to match grain size so creatures using the sand aren’t suffocated….
….Assemblyman Stone has offered a measure on sea walls, A.B. 1129. It would put into law the coastal commission’s current practice on sea walls, allowing homes built before 1977 to install barriers. Homes developed after that can apply for a sea wall permit but aren’t guaranteed to get one.
The bill also would give the commission authority to fine people who put up sea walls without a permit, he said, or who obtained only an emergency permit. The latter requires people to go back and secure a permanent permission. Stone said there are about 140 sea walls that fall into those categories.
“Everywhere we armor as the seas rise means that we’ve lost that for public access,” Stone said. “We need to make sure that we have beaches.”
Scientists at the University of California, Riverside predict California will get an average of 12 percent more precipitation through the end of this century, compared to the last 20 years of last century. Credit: UC Riverside Strategic Communications
