Wednesday, March 25, 2009
Like other shorelines around the world, San Diego County's coast is at risk of being swallowed by the ocean. UC San Diego researchers say the sandy beaches we walk on today could be gone in our lifetime. KPBS Environment Reporter Ed Joyce tells us that could hurt the state's number one industry - tourism.
(Photo: Restaurant row along Highway 101 in Cardiff is one low-lying area that could be at risk from sea-level rise. Ed Joyce/KPBS )
"I'm standing on a thin stretch of beach in Cardiff south of the Charthouse restaurant. It's high tide and the waves crash on the shore about one-hundred yards from Highway 101," Ed Joyce says.
This is one area on San Diego's coastline that could be permanently lost because of sea level rise and other factors.
UC San Diego's Reinhard Flick has been studying the California coast for nearly 40 years.
"All of this stuff that we've built on the coast both privately and publicly is going to have trouble with a 10 foot or certainly a 20 foot rise in sea level," he said. "And I think that's probably out of the question still for the next 100 years, 10 feet or 20 feet, but not in the next 500."
The Scripps Institution of Oceanography researcher says by 2050 sea level is expected to rise about 1 1/2 feet along our coastline.
Reinhard says that isn't enough to put restaurant row in Cardiff under water.
"Unless there is some catastrophic or unexpected relatively low probability collapse of a major ice sheet in the next 20 to 50 years," he said. "The chances of that have increased in the last few weeks, in the last few months, as observations from Antarctica and not just Antarctica, but the melting of Greenland have come to light."
In the meantime, UC San Diego researchers have launched the wave inundation project.
"When people talk about sea level rise, inundation in the future, one of our focuses is we don't have a good handle on it right now," said Michele Okihiro.
Michele Okihiro works with the Coastal Data Information Program at Scripps. She says the goal is to create a science-based model that can be used to predict when the ocean may overrun low-lying coastal areas.
"Being able to validate our models and the conditions when inundation might be bad now will help us to then forecast and predict for the future," Okihiro said.
She says coastal cities can help by identifying problem areas and observing wave flooding.
One volunteer observer is Kathy Weldon. The city of Encinitas employee monitors the beach in Cardiff along restaurant row.
"We're basically just looking for when the high tide reaches the road. It's very simple, and just taking pictures to see when that inundation occurs," Weldon said. "So today on this high tide we really don't have any surf, or hardly any surf, so that's not pushing it as high up to the road as say in February."
(Photo by Ed Joyce/KPBS)
Scripps researcher Reinhard Flick says four factors combine to create dangerous flooding along our coast: tides, storm surge, wave runup and longer term, sea level rise.
"If they occur at the same time, that's when you have the most serious kinds of flooding, inundation, beach erosion and all of the havoc and monetary loss, and damages and even loss of life along the coast," Flick said.
He says that's why planning now is critical, especially for major public works projects, like sewage treatment and power plants.
"Given the long lead times on some of these big projects it is never too early to start thinking about these potential problems in the future," Flick said.
In San Diego County, Mission Beach could eventually become submerged and inundation of the Sacramento-San Joaquin Delta with brackish water could jeopardize the main source of water for California.
Flick says that seawalls causing passive erosion will likely combine with sea level rise to doom some Southern California beaches.
"If the beaches disappear it's not just a sort of a loss of the "baywatch mystique" but it's also a huge economic impact. Coastal-dependent tourism is the single biggest coastal-dependent industry in California," Flick said.
Flick says there are stretches of sand in Southern California that just a few decades ago were part of the beach, now those areas are underwater except at low tide.
He says the Scripps wave inundation project could serve as a planning tool to make wise decisions now, to prevent more serious damage in the future.
Ed Joyce, KPBS News.