Not that it could be calculated but I'd like to know how much of the housing number is just grass. The golf course acreage was surprisingly high to me and I'd bet the majority of the housing segment is lawns. I do like how the USDA classifies golf courses as low economic importance.
40 million acres of turf grass. Golf courses are 2M, so I don't think it's a stretch to say that all the lawns, roadside grass and parks in urban areas are the other 38M acres. That would put urban grass at about half the urban area from the map (69.7 M acres).
I'm not at all a fan of lawns but one of the things Americans in general forget is that if you water them, they turn brown and go dormant, they don't die. Up in Seattle lawns turn brown from Easter through Halloween. Here in LA they suck the reservoirs dry. If I ran the USDA I'd bring back victory gardens so fast.
The easiest explanation is we're huge. We're so huge we're wasteful so you get giant lawns and zero public transit in some larger cities. That's the Atlanta metro area. I live somewhere in there. To efficiently move from one end to another, or one county to another really, without a personal vehicle is impossible. That area has to be larger than some small countries.
You should see the street map in the part I'm in at standard zoom vs. the suburb I lived in to the east when I moved here. This place is what happens when civic planning is ignored. I think they just paved every dirt road available in the 60s and 70s and said it was good enough. I basically live in the petri dish of things that can happen when local government fails.