Gross has made a good summary of some of the arguments against looking for salvation in ethanol made from corn. I would like to add a few other considerations.
The first is that a good case can be made that using grain corn to make vehicle fuel results in a net energy loss. That is that it takes more energy to produce the ethanol than is obtained when it is burned. This argument, if true, demolishes all the politically motivated measures to increase the use of grain corn for this purpose, including the subsidy mentioned by Gross, along with all the other farm programs designed to enrich corn growers. But, hey, corn growers are a politically potent group in a large number of states and well organized.
It wasn't long ago that third world countries were complaining about how our agricultural subsidies were making corn too cheap on the world market, thereby driving subsistence farmers there out of business. The increases in the prices of grain corn as a result of ethanol production have enabled these third worlders to grow their own corn profitably. This could have the beneficial effect of reducing these countries need for cheap grain from relief organizations, as well as rebuilding their rural communities (think Mexico).
One thing Gross didn't mention is the fact that if all the cropland in the world were made available to ethanol production, there still would not be near enough to supply fuel in the quantities used today. There is a real danger that, as fuel prices rise, land will increasinglly be switched from food to fuel production. The rural poor may have to starve in order for us to keep our SUVs going.
It is becoming increasingly clear that, as petroleum supplies dwindle, we will have to make profound changes in our life style. Let's get on with it.
