Rising sea levels could damage city facilities, beaches, roadways in Encinitas

Changing global climate conditions over the next century will likely result in storm-tossed waves tearing out portions of Coast Highway 101 in Cardiff far more frequently in the decades to come.

Meanwhile, Moonlight and Cardiff State beaches could both regularly battle flooding troubles, and the lifeguard tower at Swami’s Beach could be at risk if the sea levels rise as forecast, a panel of scientists and city officials said during a forum May 8.

There’s also likely to be damage to less visible city facilities, including the city’s drinking water and wastewater systems, said Crystal Najera, the city’s Climate Action Plan program administrator. All these issues make it imperative that the city create a Coastal Vulnerability and Resiliency Plan and update part of its General Plan, she added.

Hosted by the city, Tuesday night’s panel discussion brought together some of the region’s top beach sand researchers. They described their ongoing work and discussed how beach conditions may change in the decades to come as the polar ice caps continue to melt and global temperatures rise.

Bob Guza, professor emeritus for the Integrative Oceanography Division at Scripps Institution of Oceanography, said there’s no doubt that sea levels will rise as the ice melts, particularly during the second half of the century. But, he said, “the question is how much and people are guessing.”

It’s hard to get a handle even on current conditions when it comes to beach sand movement and other coastal issues, he said. After doing more than a decade of beach sand studies, he can confidently say that sand replenishment projects, which add fresh sand berms to area beaches, have helped protect Coast Highway 101, he said. But, he said, much more research is needed.

Adam Young, a fellow Scripps researcher who is mapping coastal bluff collapses, agreed.

“Basically, there’s a lot we don’t know and we need to do more research,” he said, adding that there still is time to do this work because the most significant impacts of climate change are expected to hit midway through the current century or later.

-- Barbara Henry is a freelance reporter for The San Diego Union-Tribune.