Earth Policy Institute President Lester Brown threw out a statistic – almost in passing -- during his conference call Thursday that caused me to pause: The corn required to produce one SUV's 25-gallon tankfull of ethanol could feed the driver of that SUV for an entire year.

Assuming, of course, you could get that SUV driver to actually eat anywhere near that much corn. And what are the chances of that? Not much, especially if that SUV driver lives in the United States, where he'll more likely chow down a nice big steak … cut from a cow that'd been fed the corn.

And that cow will consume somewhere between 4.8 pounds and 16 pounds of corn per pound of beef (depending on who you ask) before the meat gets to your table. Still, that works out to quite a bit of food for each gallon of gas (not to mention a good reminder of the far-reaching impacts of the American meat-centric diet).

But is the issue quite that black and white? The food versus fuel debate often gets hung up in "either/or" mode, fixating on corn as the be all, end all feedstock for ethanol plants. What's more, they tend to focus on whether or not the edible parts of the corn should be used as a fuel feedstock.

In reality, corn should only be looked at as a stopgap feedstock. It's the low-hanging fruit, the mature technology. The real revolution will be in cellulosic ethanol, which is brewed from all sorts of bio waste (including, by the way, the parts of the corn NOT useable as food) and from switchgrass that can be grown in soil too poor for much of anything else.

So to me, the food versus fuel debate risks missing the point. Today, it's cheaper and easier today to make ethanol out of corn, but once the technology necessary for creating cellulosic ethanol matures, the game will change, big time.

That's because the United States alone has an estimated 1 billion tons of biomass available each year, which works out to enough for 100 billion gallons of cellulosic ethanol. That's enough to replace nearly half the 140 billion gallons of gasoline the nation currently consumes each year, while traditional corn ethanol can only replace 20 billion gallons, or about 14 percent of the gasoline consumed. What's more, cellulosic ethanol turns out to be a more environmentally-friendly option as well: It requires little to no pesticides or fertilizer, provides significantly more energy per acre and emits less greenhouse gasses than corn.

President Bush has called "to make cellulosic ethanol affordable within six years." Let's hope America rises to that challenge. Because if it does, the whole "food versus fuel" debate might seem, well, a little corny.