We could all still Stand on Zanzibar(1), but I'm also reminded of a Harlan Ellison short story I can't locate that had a very large number of humans living in c

We could all still Stand on Zanzibar(1), but I'm also reminded of a Harlan Ellison short story I can't locate that had a very large number of humans living in cramped, vertical dwellings with the rest of the Earth given over to intensive farming. It might be possible to support many more people, but that doesn't mean it's a pleasant or admirable objective. There's also the deletorious effects of the "green revolution"--when the natural gas for making nitrogen-based fertilizer runs out, the shock to the minimal remaining topsoil will be famine-ifying. (1) http://en.wikipedia.org/wiki/Stand_on_Zanzibar http://en.wikipedia.org/wiki/Stand_on_Zanzibar