It’s already too late to stop global warming, say scientists. No matter what we do, sea levels will rise. Some climate activists have even released an interactive map that will let you see how much of, say Washington, DC, will be under water in the next century, with the flooded zones depicted in blue. (Not all of it, alas).

Well, if it’s too late to stop global warming, I have a modest proposal instead: Tax the blue zones. That is, minimize the damage that will occur from flooding many decades in the future by reducing development now.

If we’re seriously worried about flooding from higher sea levels, then we want to make sure that areas that will be flooded in the future won’t be developed now. We want to limit the investment in buildings that will be swamped, and we want to limit the number of people who’ll have to move. And we want to encourage people who live in those areas now to move away in the near future, before they’re flooded.