In that scenario, housing only goes down in value because the underlying conditions make the area unlivable, leading to mass migration elsewhere (which we're already seeing in some parts of the world) and a commensurate drop in economic activity in the area. It doesn't make housing more affordable, it just makes it less desirable, plus it puts upward pressure on housing markets that receive climate migrants. It will effectively make housing less affordable because it takes certain geographies out of the equation. Not only are they not making more land, but there will start being land that becomes effectively uninhabitable. The status quo has already priced all of this in. There's no condition where housing becomes more affordable without meaningful changes to how housing is owned and distributed.

But, to be less doomer about it, there is nothing inherently blocking the creation of better ways to do housing. The market won't provide affordability, but that doesn't mean that housing can't be affordable. It's not a problem that needs to be handled all at once at all levels, the problem can be broken down and solved in different ways in different places. There are plenty of levers to pull to solve the problem, and the pressure to start pulling those levers is only going to grow. It's a good area for organizing, and for finding people who are already radicalized, it's just that the current status quo is shitty and isn't going to get better without changes.