Where Elephant Grass Stops

criticalmass · Posted: Wed Oct 10, 2007 3:52 pm Post subject: Where Elephant Grass Stops

This question is aimed at all the experts, especially those versed more in agriculture and botony...
I need some fuel for dispelling biomass locally as the savior fuel for fossil fuel replacement. In order to put yourself in my place, imagine you have dozens of sceptical friends. "Yeah, like that's difficult to imagine." You've succeeded to date to explain to them that ethanol is nothing more than a cleaner substitute for gasoline and can only be run as a percentage of fossil fuels in most vehicle configurations. You've also been successful at explaining that hydrogen can't just be mined and takes energy to produce, and is really nothing more than an effective carrying vehicle as far as use on a mass scale- sort of like electricity stored in batteries.
So now the hard part. Our culture is so urban that most of these friends cannot fathom why we cannot grow an infinite (or nearly infinite) supply of things like highly cellulose elephant grass. They can't seem to get their heads around key hang-ups like crop rotation, soil depletion, limited land supply for food, etc. Is there an eloquent argument or trustworthy statistics that places a theoretical limit on how much land we could actually grow sugar canes and elephant grasses on to be used as fuel over food?
Even if there is a good link with related material I would be more than willing to read some arguments there.