It's annoying for coastal areas, and a problem for beach houses, but California isn't really that vulnerable to rising sea levels. The Pacific Coast is mountainous and the ground slopes upward in short distances.
Here's the US topo map.[1] Look at vulnerable spots, such as Malibu and Oceanside. Three blocks inland you're 20 feet above sea level. Almost all problems are on the ocean side of the Pacific Coast Highway, which was a marginal place to build anyway.
Cliff edge erosion is an ongoing problem. That's why CALTRANS gave up on Devil's Slide as a road route and built the Tom Lantos Tunnels further inland. Small changes in sea level don't affect hundred-foot cliffs that much, though.
The places that really suffer from rising sea level are river deltas, sitting on deposited sand just barely above sea level. In the US, New Orleans has the worst problem. New York City has problems, and they're building coast defenses against storms. China's coastal cities are mostly on river deltas with really flat terrain. That's why China has to build ports way off shore, reached by miles of bridges, to get to deep water.
I just dodged being stuck on the Outer Banks or evacuating for a hurricane which has now closed Hwy 12 based on which week the family agreed on for the annual beach vacation:
Animats · · focus · HN ↗
Here's the US topo map.[1] Look at vulnerable spots, such as Malibu and Oceanside. Three blocks inland you're 20 feet above sea level. Almost all problems are on the ocean side of the Pacific Coast Highway, which was a marginal place to build anyway.
Cliff edge erosion is an ongoing problem. That's why CALTRANS gave up on Devil's Slide as a road route and built the Tom Lantos Tunnels further inland. Small changes in sea level don't affect hundred-foot cliffs that much, though.
The places that really suffer from rising sea level are river deltas, sitting on deposited sand just barely above sea level. In the US, New Orleans has the worst problem. New York City has problems, and they're building coast defenses against storms. China's coastal cities are mostly on river deltas with really flat terrain. That's why China has to build ports way off shore, reached by miles of bridges, to get to deep water.
[1] <a href="https://en-us.topographic-map.com/map-9t5k57/Venice-Beach/?center=33.18363%2C-117.36954&zoom=16" rel="nofollow">https://en-us.topographic-map.com/map-9t5k57/Venice-Beach/?c...
WillAdams · · focus · HN ↗
<a href="https://www.outerbanksnews.org/post/n-c-highway-12-damaged-closed-on-pea-island-as-nor-easter-impacts-the-outer-banks" rel="nofollow">https://www.outerbanksnews.org/post/n-c-highway-12-damaged-c...
(and they have an on-going beach replenishment effort as well)