Yucatan Garden
   PHOTO BY BRYAN WELCH
We haven’t traditionally assigned much value to natural productivity except when it was producing something we could eat, wear or burn for fuel. Predictably, David Tilman’s research is inspired by the hunt for new biofuels — renewable resources that might replace petroleum products. He suggests that someday our cars might run on so-called “cellulosic” ethanol created from grass. Ethanol created from cellulose could be derived from nearly any plant, so why not the plants that naturally grow more profusely, the native plants of the prairie?

Cool idea, unless your children are among the millions currently starving for lack of corn, wheat, rice or some other staple foodstuff that might be grown on that property. We’ve clearly demonstrated that we can spike grain prices with burgeoning new demand from ethanol manufacturers. Poor people around the world are straining to pay for food made expensive this year by the demand for ethanol.

On top of everything else, there’s good evidence that while our population is expanding we’re also wrecking some of the natural machinery we use to create our food. Setting aside the excesses of industrial agriculture and the short-term damage they do to farmland, we’re still tearing down important environmental assets the old-fashioned way, by burning forests and overgrazing grasslands.