On Twitter, someone asks whether water issues mean that the trend of internal migration of the American southwest can't be continued. I had actually been mulling a variation of that question yesterday afternoon as I drove from tornado-stricken Oklahoma to drought-ravaged Texas: at some point, are people going to start prioritizing weather-proof places? It seems like they would do, but I suppose the issue is that bad weather is somewhat subjective: people in Houston dodge the extreme winters of Chicagoans, but Chicago doesn't deal with the horrible summers or occasional hurricane; San Franciscans get a temperate climate at the cost of some running anxiety about earthquakes. I can imagine water being a constraint on population growth in the southwest, but it might not be obvious that water is the issue. What we might see is that constrained access to water limits industry--agriculture relocates, or manufacturing becomes more expensive. That would weaken the pull of the jobs magnet.