And in a related news flash, biofuels have just been officially approved for use in civillian commercial aircraft. I'm no expert, but aviation biofuel uses different organic inputs from the various ethanol technologies, so it is a different technology track from ethanol. The inputs are also not typically food for people, unlike the current main inputs for ethanol, like corn or sugar cane.

I know that the Dept of Defense has been looking into biofuel for its military planes, but I don't know if that is still just in the experimental phase. One day, we may be sending our aircraft carriers and soldiers to novel new destinations to protect our supply of plants or algae that go into making aviation biofuel. Who knows.

However, as Byrd_Hunter points out, this promising news still doesn't get around the issue of fossil fuel-derived fertilizer to keep crops growing, but as natural gas gets permanently expensive someday, we may find a viable alternative as we are just beginning to do for transportation fuels.