LOS ANGELES – A wave of heavy rain has accelerated landslides and contributed to damaging coastal erosion in California, leaving multimillion-dollar homes on the edge of cliffs, falling a hundred feet of palm trees into the surf and forcing the closure of a historic chapel .
The state is now drying out, but the effects of a second season of extreme rainfall could be felt for years to come. Climate change, which is intensifying rainfall, driving sea level rise and making droughts more severe, is contributing to a number of forces reshaping California’s landscape.
This season’s storms have offered Californians a dramatic revelation and a taste of the consequences of a warming world, while slow-moving processes that scientists have warned about are clearly accelerating. Mike Phipps, a geologist with the geotechnical engineering firm Cotton, Shires and Associates, said landslide risk and sea level rise will combine to reshape California’s coastline.
“The coastline is at great risk,” he said. “As those cliffs try to recede, the buildings will be threatened and there are situations across California where buildings have been razed and buildings are falling into the ocean.”
According to the National Drought Monitor, two years ago, 100% of the state was in drought and rain was urgently needed. Now only small parts of the state – 7% in total – are considered “abnormally dry” and residents are begging for mercy due to the heavy rains.
The shift began last winter when more than a dozen atmospheric rivers battered the state with precipitation, easing drought conditions and saturated the state’s hills with moisture.
This year the extremes have only continued.
This month, downtown Los Angeles recorded more than 12 inches of rain — four times the average monthly average and nearly twice as much rain as what fell in all of 2022, according to National Weather Service data.
The rainfall has pushed some slopes to the edge, making landslides more likely.
During the most recent storm, the city of Los Angeles said it received 63 reports of debris flows or mudslides. After a more severe storm earlier this month, the city said it had received calls for 592 mudslides. At least 16 buildings have been ‘red tagged’, meaning people have not been denied access due to the risk.
“If you’re dealing with a constant barrage of storms, you’re most likely going to have water accumulating on the slopes and that increases your chances of slides,” says Nate Onderdonk, a professor and geomorphologist at California State University Long Beach.
In the community of Rancho Palos Verdes, a landslide-prone coastal city in Los Angeles County, recent rains have accelerated land movement and caused shifts in places where landslides have not previously been mapped, according to a city news release .
Onderdonk said layers of sedimentary rock in the area have tilted toward the sea. When weak clay layers become saturated with water, they expand and often shift because they have very little friction.
The intense rainy season has increased and expanded the areas of concern. Decades ago, geologists devised a plan to dewater the slopes in the Abalone Cove landslide area, significantly slowing the movement, Onderdonk said.
But about a week ago, the growing movement forced the closure of Wayfarers Chapel, a Frank Lloyd Wright Jr.-designed church. designed National Historic Landmark at Abalone Cove.
“That caught my attention,” says Onderdonk. “This is an area that has apparently stabilized.”
With homes and roads at risk, the city of Rancho Palos Verdes has asked Governor Gavin Newsom to pursue state and federal emergency declarations, which could expedite emergency solutions through the permitting process.
Many coastal cities along the California coast are exposed to the risk of landslides.
Homes in Dana Point made headlines this week after The Los Angeles Times and other media organizations published drone footage showing several large coastal homes high above landslide debris.
Scientists are still investigating how climate change will alter the frequency and severity of landslides. A 2022 study published in the peer-reviewed journal Geophysical Research Letters found that landslides are sensitive to changes in climate and move much faster in wet years than in dry years.
A 2019 study published in the Bulletin of the American Meteorological Society found that landslides in the San Francisco Bay area coincided with atmospheric river storms about 76% of the time.
Scientists say atmospheric river storms on the West Coast are becoming more frequent and intense as a warmer atmosphere can absorb and transport more water vapor.
California’s cliffs fight more than gravity.
Rising seas and more intense storms are chewing away at the state’s beaches and coastline, something climate scientists have warned about for years. A report from the United States Geological Survey shows that as sea levels rise due to climate change, Southern California could lose up to two-thirds of its beaches by 2100.
Global warming – caused by human use of fossil fuels – is the main cause of sea level rise. Melting glaciers and polar ice caps are causing sea levels to rise. The volume of ocean water also increases as it warms.
It is a dynamic that has caused many to see their beaches shrink.
Homeowners Edward and Debbie Winston-Levin, who live in Dana Point, California, in a home overlooking Capistrano Beach, said they have seen the sea wash away over time.
“There used to be a volleyball court and a basketball court down there, all of which have eroded,” said Edward Winston-Levin, 77. “And on a day with a lot of surfing it covers the parking lot.”
They fear that their property, which is located on a steep slope, could one day slide into the sea.
“If one slide starts, it’s going to continue. We’re going to lose our homes with, you know, beautiful views,” he said.
Many coastal cities are making drastic changes in an attempt to adapt.
In San Diego, plans are underway in the resort town of Del Mar to move train tracks now considered too close to the coast. And in San Clemente, the state plans to build a $7.2 million wall to fortify a landslide area, in an effort to stop a sliding hillside that has cut off rail service through Orange County.
On Isla Vista, near UC Santa Barbara, a collapsing cliff recently forced students to evacuate their homes and now several of these buildings are being rebuilt further from the coast.
Experts say this changing landscape could lead to a dilemma over time: save the state’s iconic beaches or cordon them off to protect the homes on the cliffs.
“That’s a very complex question,” Phipps said. “It’s clear that Californians love their beaches and everyone wants to preserve their beaches. There will be places where that is possible, but in many places the beaches are shrinking and being lost.”
This article was originally published on NBCNews.com