written 11 February 2024
published 18 February 2024
"California Against The Sea", written last year by Rosanna Xia, is an in depth look at the fact of rising sea levels, how it is already impacting California cities, and what people are doing in response.
Sea level rise is caused by melting of land-based ice, expansion of warming ocean water, and coastal land subsidence. From 1880 to 2022, the ocean rose an average of 9 inches, but that was not uniform around the globe. The US east coast experiences higher rise impact than the west coast, because the Atlantic is warmer than the Pacific. Florida and the Gulf coast have the highest domestic rise impact, because the North American tectonic plane is still rebounding from the loss of the 3 mile thick sheet of ice that melted 12,000 years ago. As the northern edge of the plate continues to rise, the southern edge sinks.
Plate tectonics aside, the primary driver of sea level rise is the rapidly warming planet, a consequence of our energy policy. 90 percent of planetary warming goes into the ocean, the energy equivalent of seven Hiroshima bombs every second, 24 hours a day, all year long. And this is accelerating. Barring unforeseen increases, sea levels are projected to rise another few feet by 2050, and more than 6 feet by 2100. But problems are already here in the form of greater storm surges and accelerated coastal erosion.
In the last 50 years, "nuisance flooding", also called "sunny day flooding", is 9 times more frequent. The City of Imperial Beach, south of San Diego, spends a significant percentage of their annual budget clearing sand from the roads after high tide events. But increasing sea levels means large portions of the city will become flooded and uninhabitable.
Coastal erosion has always been a California fact of life. Encinitas used to have 7 streets west of highway 1, but now the western most is 4th street. As the sea rises, another 130 feet of bluff retreat is expected by 2100. In Pacifica, houses are falling into the sea. In Del Mar, the rail link between LA and San Diego is threated by erosion and landslides.
Over geologic times, sea level has changed from 200 feet higher to 400 feet lower, but human civilization grew in a time of relative stability. Trillions of dollars of invested infrastructure are now threatened by changing reality. In a conflict between human desire and the will of the ocean, the water wins. The choices are to fight the facts, or plan for resilient adaptation.
Since coastal California is some of the most expensive real estate in the country, many landowners choose to fight, trying to armor the coast with sea walls. Where seawalls are built, the beach is destroyed, as waves scour the sand away. Seawalls can cost millions, and the protection is temporary, eventually being over topped, or undermined, some destroyed in a matter of weeks.
Low lying areas trying to defend with sea walls find the rising ocean forces the inland water table to rise as well, causing fresh water flooding. A seawall might delay the demise of a home on a coastal bluff, what about infrastructure that has to be at sea level for commerce and transportation?
Sea level rise is forcing a re-examination of our entire notion of property rights. Native people knew we don't "own" the land, but are transient guests, and lived in ways that accorded with the changes of nature. Western civilization killed off those naive ideas, and made lots of money selling "rights" to the land. Our culture is rigidly rooted in certainty and endurance, which is in conflict with the dynamic reality of nature. The coast line is a fixed concept, but a moving reality, always changing, sometimes very slowly, and other times in rapid transformation.
Much like the foolish king who commanded the tide to halt, humanity is confronted with a situation that can't be forced into submission by application of money or power. We need to become more pliable, learning to work in harmony with nature, not be at war. This is a profound social transformation, but the ocean is inexorable. Most coastal California communities have begun discussion and planning for how to address the issue. California Against The Sea describes some of the emerging solutions, none of which have yet to be been applied on a larger scale. But the discussion has begun.
