From the article:

> A slow-moving emergency is lapping at California’s shores— climate-driven sea-level rise that experts now predict could elevate the water in coastal areas up to 10 feet in just 70 years, gobbling up beachfront and overwhelming low-lying cities.

There is a map that show what part will be flooded with an increase of 10 feet. It's not the whole state. Some cities will be fine. Some cities will be doomed.

> A consensus of scientific research makes catastrophic projections that, in the worst case, will be reality by the end of this century: [...] More than 42,000 homes in California will be under water—not merely flooded, but with seawater over roofs.

For comparison, there are like 40 million people living in California, so a good guess is that there are 10-20 million of homes there. So 42,000 sink homes are only 0.5%-0.25%, but it's a lot if it's your home.

California generally has a steep coastline, but none the less a lot of housing exists in low lying areas. That said California's policy makers are already trying to figure out what they are going to have to do.

that's erosion.

If we really care we hire the Dutch to build a seawall.