There was an interesting bit about urban sprawl. ("Is Urban Sprawl an Urban Myth?")  Turns out, it's not as bad we think.  Cities have grown, but the development is not more scattered.

I guess it depends on your metric. If you compare us to Europe, then we have horrendous sprawl. Over there, you come upon a compact little village, and then leaving the village you are back into farmland unspoiled by half a dozen little subdivisions. Here, it seems like we have just sprawled all over good farmland, and I think we will ultimately regret that.

Depends where you look, Robert... France has sprawled catastrophically over the 20 years I've been commuting here. though, it's true, generally by expansion around the nucleus of existing villages, rather than green-field development. But there has been a major phenomenon of urban flight, and it's still going on. Will probably take a few years, and political will, to turn around before we start re-densifying the places with the good infrastructure.

When visiting the US, I was struck by the impression that only the best, easiest agricultural land is used. e.g. the hills of North Carolina : all that superb rainforest was destroyed, the land grazed or cropped for a little while (a generation or two?) and is now reverting to forest. What happens next? Clear the forests again to plant biomass for fuel?