=Eric, I think you are very unrealistic about the potential of solar, wind, tidal, and wave. Currently, all those "alternative" forms of energy generation account for less than one percent of the energy that is generated nationally. I think you need to start working the term "carbon tax" into your discussions, as we need to drastically reduce the amount of energy that we are using.=
Without a real paradigm shift in the thinking of the average American, any group that proposed such a tax would not stay elected for long. I don't know how to convince individuals that their respective footprints are part of the global problem. But they are.
He reminds us that there is no such thing as a "free byproduct of growing food crops,"
Sue is right on about land and soils. Presently with cheap natural gas agriculture, they have been very nearly ruined as they produced "unnatural" yields. With natural gas in decline (and oil most probably too at this juncture), we need to be restoring them big time, rather than exploiting them to grow food simply because we want to maintain personal transportation vehicles. The downside (which has been written about a lot more lately, fortunately) includes increasing food prices, creating hunger and starving the poor worldwide, and contributing to further degradation of the planet.