I have a friend who works for an environmental firm in California. They are specialists in identifying 50-100 year climate impact on new commercial construction. Every single project they've been working on for the past decade assumes within the next century there will be extensive sea-level rise wiping out most shorefront properties. He told me about it so glibly I didn't believe him, and he followed it up with: "oh yeah, every construction firm knows the coast is fucked, its common knowledge."
In 50 to 100 years we might have come up with a solution for coping with higher sea levels. Perhaps just elevated platforms to create an entire new city foundation 20 feet above the water. It’s not a big deal.
I think in 50 years we might be about as limited as we are today -- some technologies significantly (but not magically) improved, but much more restricted energy and material availability. We've undergone the greatest revolutions in history in the last century, and fundamentally building technology and energy usage isn't in a magical state compared to early 20th century. NY's Empire State was built in the 1930s. Roman buildings are better in some way than modern equivalents.
A significant sea level rise (>10m) would mean rebuilding the housing of >25% of US's population (~40% are living within 100km of the coast). Imagine 1 in 3 people needing to rebuild their homes. Because of our current mode of action, we're quickly approaching most environmental limits at the same time. If we assume availability and (inverse) cost is approximately proportional to natural reserves of a mineral, and that consumption is also approximately inversely related to cost, then most minerals are expected to deplete at similar times. That I know of, copper, several rare earth minerals, lithium, phosphor, and who knows what else.
Imagine the social shock this will bring, specially if current cultural, social and economic paradigms are maintained.
What is interesting to me is that we have the capability to do so much, but we always pass the buck to someone else and refuse to come together or take ownership of any problem that isn't beating down out front door.
It's never an issue with resources. It's an issue with community and leadership, and the refusal of the community to appoint leaders who lead.
Does this knowledge manifest in any way in the built environment? A lot of recent development in the Bay Area particularly has been below what should be considered a reasonable high water mark 50-100 years from today.
Most of the time the investors are adamant on building in a particular area, so it largely results in higher-elevation construction (think elevated freeways & roads), abandoning underground levels (parking, storage, dwelling), and heavily reinforced foundations.
Because people rich enough to buy coastal California real estate will be dead or in a nursing home by the time this happens. Or if they’re young, they have enough money that loosing a couple million is a cheap price to pay for living on the beach.
"Coastal real estate" in California is in no way endangered by sea level rise, being characterized by bluffs. Sea level rise imperils people who live along undesirable shores in places like Stockton and Newark and East Palo Alto.
It looks like with California beaches you typically don't have to go as far back to find higher ground than you do with say Florida beaches. From the pictures I've seen a lot of the beachfront houses are built one stilts, often with the back at the level of that higher ground behind the beach.
I don't think they built this was anticipating climate change--it was so if a bad combination of tides and storms pushed water far enough up the beach to reach where the house is it would be under the house instead of in the house. Nevertheless, it looks like a lot of these beachfront houses could take a meter or two of sea level rise and still be above water.
They'd have a lot less beach, so it would probably change the kind of person who wants to live in them, but it is quite possible that they would remain very desirable.
As far as things not actually on the beach goes, playing with the interactive sea level rise map from NOAA linked in kibwen's comment, it looks like there are a few places (such as the Long Beach area) where you get some extensive loss of land a ways in, but for most places on the Pacific coast it is just the beach itself that gets lost. It is more of a mixed bag for places not on the coast but on rivers or bodies of water connect to the coast.
Water is not simply a presence; it has weight, it has impact on everything. If the water level rises, it must have an impact on the coastline itself. Water might never reach the house, but it might make it impossible to maintain nonetheless.
The same reason places like Miami have a red hot market and construction is booming. People either can't fathom sea levels rising to the point of catastrophe, or they think a 50-100 year timeline is long enough to not really be relevant.
Miami Beach is one of the more precarious positions worldwide and the real estate market there is barely reacting to it with high elevations now commanding a slight premium over prior years even in poor areas. It looks like we collectively are only going to react after the fact even if some of us are worried about it individually.
Most condominiums built today using concrete-rebar construction will be torn down in the same timeframe. Concrete rebar has a lifetime of about 100 years, even when properly maintained.
But nobody buying a condo today looks at what the resale value will be in 50 years.
For institutional investors it will react maybe one quarter before it actually happens, and for retail it could continue even with their feet in water with good marketing.
His surprise is still reasonable, because as time goes on our information will get more precise. So, if this is true, you could buy today and then be unable to sell in 10 years as the market moves.
