One of the common varieties of cognitive kaleidoscope on the market today is the bio-fuel version. It's a fairly complicated device with lots of odd shaped bits that can be selected and rotated to make all sorts of pretty patterns - almost any pattern you want. There are a couple of favorite patterns though and a heated dispute between advocates of one or another.

The ethanol pattern has been both praised and criticized. A new argument that finds it beautiful comes from a group that has reconsidered previous arguments, fixed their defects, modernized them and concluded that the critics were just twirling improperly.

They assessed the studies' assumptions and then reanalyzed each after correcting errors, inconsistencies and outdated information regarding the amount of energy used to grow corn and make ethanol, and the energy output in the form of fuel and corn byproducts.

Once these changes were made in the six studies, each yielded the same conclusion about energy: Producing ethanol from corn uses much less petroleum than producing gasoline. . .

The team said it found numerous "errors, inconsistencies and omissions" among the studies, such as not considering the value of co-products of ethanol production - dried distillers grains, corn gluten feed and corn oil - that boost the net energy gain from ethanol production. Other studies overestimated the energy used by farm machinery.

I've followed this debate and can testify that there is some truth in this. Omitting the value of co-products is a common twirl by those who find the ethanol pattern unlovely. Some even argue that the corn should just be burned to make heat for homes, industry and power stations rather than be converted to ethanol. They base their arguments on the energy yield of the ethanol vs. that of burning the corn. This compares the energy of the starch component of corn used for ethanol brewing against the energy of the whole corn kernel. Not quite apples and oranges but similar.

But this new study omits some bits too.

However, the UC Berkeley researchers point out that there is still great uncertainty about greenhouse gas emissions and that other environmental effects like soil erosion are not yet quantified. . .

some studies ignored the use of crushed limestone on corn fields, which can be a significant energy input because of the need to pulverize the rock. Farrell noted that some numbers needed for the analysis, such as the amount of limestone applied, are just not known reliably. . .

corn production has other negative environmental impacts associated with fertilizer, pesticide and herbicide use. These need to be taken into account when considering the balance between corn ethanol and gasoline . . .

Water use, biodiversity reduction, soil CO2 and methane emissions from cultivation and a host of other considerations are also glossed over, mainly by pointing to a future when the cellulose rather than just the starch component of plants can be used in a multi-step process that uses microorganisms to first turn the cellulose into starch so that other microorganism can turn the starch into ethanol. It is assumed that the ethanol yield will then be so great that any environmental or production costs will be insignificant in comparison. They also fail to consider other competing uses for the biomass or the resources consumed in its production, and switch back and forth between static views of present behaviors and dynamic futures when it favors their arguments. For example they say that there are "a billion tons of currently unused waste available for ethanol production", but fail to note that these "unused wastes" are resources rapidly being discovered as their value rises. They aren't wastes, they are resources that have had low values though that is changing.

They clearly want ethanol to be made, but it isn't entirely clear why they want this. They seem to discount the emissions aspect, giving it a cursory nod, and assume that "an oil-free future" is a value in itself.

The analysis, appearing in this week's issue of Science, attempts to settle the ongoing debate over whether ethanol is a good substitute for gasoline and thus can help lessen the country's reliance on foreign oil and support farmers in the bargain.

It's not clear why reliance on foreign oil is a problem (yes, I've heard the security talk and spite the Arab talk), or why we want to support corn farmers. Aren't they subsidized already?

I think I prefer the future scope to the kaleidoscope. The patterns aren't always pretty but they seem more useful. The future scope shows nearly a billion food insecure people in the world now and 3 billion more on the way. It's hard to see how burning biomass for energy makes any sense when this is our future. We need to produce a lot more food with our limited land and water, and produce a lot more energy some other way since those folks will need energy as well as food.

When you decode the buzz words - bio-fuel, bio-mass, oil-free, foreign oil, etc. - you end up with proposals to revert to an earlier time in history when plants and dung were all the fuel we had. Food was scarce enough that gloomy predictions of impending doom were made while beasts of burden consumed large quantities of crops. For a few decades food production increased greatly while at the same time beasts of burden were replaced by fossil fueled engines. It desn't seem to make sense to have our engines replace beasts as competitors for food even if our technologies are very much more advanced than they were in the past since there are also lots more of us.