The argument that these aspirations are unsustainable seems too conservative
to me. After all, the resource that matters is human effort, and that is being bent to making homes where people want them, as opposed to where 'smart growth' says they should live.
[WS:] Let's do the math, James. There are close to 7 billion people on the planet Earth now, and that number will reach 9 billion in 20 or so years. Assuming the American model of nucular ;) family, there are 4 people per household, which gives about 1.75 billion households in need of a US-style suburban house. Assuming that a US style suburban house occupies, on average, an acre of land or about 4047 square meters, those suburban houses for all would take the area of ca. 7 million square kilometers.
The total area of the planet Earth is about 149 million square kilometers, of which only about 1.5% - or 2.2 millions square kilometers, is currently covered by urban settlements. The remainder is used for agriculture, or is covered by forests, wetlands, deserts, mountains, etc. That means that your building project will expand the current urban settlements about three-fold, before we even start counting roads, airports, industrial parks, or commercial areas. I did not count parks, though, because I assume that your nucular suburban households have no need for them.
So here are the choices your building project faces:
1. Start chopping down those trees, bulldozing mountains, drain wetlands, kill the Bambi, etc. to create more lebensraum for the common volk with land aspirations;
2. Kick out those pesky farmers and build more homes on the land they cultivate;
3. Proclaim that the US suburban model is not for everyone but only for the select few, and keep the undesirables at bay or better yet, gas them, so the "entire" humanity can enjoy the lebensraum brought by the American suburban life style.
Good luck with your building project.
Wojtek