Study predicts California could lose more than half its beaches by 2100
MENLO PARK -- A new study to be published forecasts close to three-quarters of California's beaches could disappear by 2100.
Those include Stinson Beach as well as popular spots in Half Moon Bay and Santa Cruz.
Modern satellite technology is helping researchers get a better sense of how accurate their models are at predicting beach-sand loss in California and around the world.
To carve waves at the world class spot off Cowell Beach in Santa Cruz, surfers walk down a long flight of stairs to the narrow beach. During high tide, that beach is submerged.
"What you can see here is a very little amount of sand between the stairs and the main beach of Santa Cruz over there," explained Sean Vitousek, a research oceanographer with the U.S. Geological Survey.
Warming temperatures and rising sea levels will only make it harder to get to the perfect wave.
"Access is limited in these situations where beaches are lost," Vitousek said.
Vitousek has led a years-long study using mathematical models and newly available satellite imagery and data. It indicates that about one-quarter to three-quarters of California's beaches will disappear by the end of the century, depending on how much sea level rises.
"A lot of locations are chronically eroding. As that trend continues, you see the shoreline is almost completely lost or it's right up against the cliff at around 2100," Vitousek said.
One satellite image showed what a beach in Orick (Humboldt County) looked like in 1993.
Another image from 2016 showed 300 meters -- nearly 1000 feet -- of beach-loss since then.
The concern isn't just recreational access to beaches.
More roads, highways and streets have collapsed, been damaged or indefinitely closed despite shoreline armoring -- engineering protections like rock walls..
Relatively small and major storms are generating destructive waves that are crashing closer to onshore infrastructure.
Experts say rising sea levels will only exacerbate the problem. Erosive impacts have become a familiar sight along the coast such as the gaping hole that cut off access to Big Sur in recent years.
"This is a serious issue for any coastline around the world but, in particular, in California," said Gary Griggs, an earth sciences professor at the University of California Santa Cruz.
Griggs studies coastal erosion.
"Adaptation is realizing that this is happening. Santa Cruz is trying to deal with how it's taking out parts of the roads and path. What do we do?" said Griggs.
Part of the solution is more awareness.
Virtual Planet Technologies uses virtual reality to show the potential impacts of climate change. Their presentation shows what Santa Cruz beach would look like with rising sea levels.
"When we get into high end sea-level rise scenarios -- one to three meters of sea level rise -- we're going to have a lot of challenges on losing beaches all across the country and, potentially, across the world," Vitousek said.
Vitousek and a team at USGS is working on a similar study looking at what will happen to beaches on the East and Gulf coasts and Hawaii.
