There have been a number of stories lately about cities undergoing "planned shrinkage": mostly in Rust Belt cities like Detroit, Flint and Youngstown, where the population has been declining precipitously and in response, city governments have begun "landbanking," keeping abandoned and foreclosed properties instead of selling them at auction. This is a sensible response to a situation where, Planetizen blogger John Kromer writes, "no one expects postindustrial cities to return to the population levels that existed at mid-twentieth century."
On the other hand, why not? It's true that the factories that once drew people to these cities have mostly gone out of business, but the fact is that these towns have three very important things: water, the relics of pedestrian-friendly infrastructure, and a climate where large numbers of people can survive without air conditioning.
This is more than can be said for, well, most of the South and Southwest. California's Central Valley is drying up, and the Colorado River is in for some trouble. The sprawling exurbs have been the worst hit by rising gas prices. Everyone expects energy costs to rise, and that will have a huge effect the large elderly populations in Florida, Arizona and Southern California. California is already seeing its population growth slow.
If I were President... No, wait, I understand that it's hard for the President to change the country's direction much more than he is right now. If I were Dictator, I would figure out which parts of the country are really sustainable given current trends. Not moronic extrapolations of past trends, but what we can realistically expect in the future. I would divide the country up into at least two zones.
In the "least sustainable" zone, all subsidies for housing, jobs and transportation would immediately cease, and a radical plan would be put into place. The walkable cores of every town that has one would be preserved for a sustainable population level, and all abandoned or foreclosed structures in the sprawling exurbs would be dismantled and salvaged.
In the "most sustainable" zone, any plans to shrink sprawly areas would continue, but walkable urban areas would be strengthened and enlarged to make room for the migrants and refugees from Scottsdale and Orlando. Money saved by not funding highway expansion in LA could instead be spent on buses in Ohio.
Of course, I'm not the Dictator, or even the President. That's probably a good thing. But I hope that the President and his advisors are thinking about things like this. And I hope that the next time transit and livable streets advocates report on things like transit shortfalls, highway widenings and planned shrinkage, we can connect them to other environmental issues like water and the effects (not just the causes) of energy shortages and climate change.