How green is my valley (er, corn).

• Author: De Gorter, Harry
• Position: Ethanol fuels - Science & Technology

[ILLUSTRATION OMITTED]

THE FEDERAL "sustainability standard" requires ethanol to emit at least 20% less carbon dioxide (C[O.sub.2]) than gasoline. Recent rulings by California and the Environmental Protection Agency, however, have cast doubt on the methodology of the sustainability calculus and whether those standards are being met. The methodological debate is misplaced because sustainability standards for ethanol are, by definition, illogical and ineffective. Moreover, those standards divert attention from the contradictions and inefficiencies of ethanol import tariffs, tax credits, mandates, and subsidies, all of which exist whether ethanol is sustainable or not.

Ethanol is sustainable by definition. The C[O.sub.2] sequestered by growing corn is exactly offset by the C[O.sub.2] emissions that follow from burning the fuel in a car. The same observation applies to, say, consuming bourbon made from corn, but ethanol can replace energy--bourbon cannot. Hence, any sustainability standard should be applied to all corn and other crop products, and not just ethanol.

Sustainability standards are based on "lifecycle accounting," in which ethanol is assumed to replace gasoline but, in fact, it may be replacing coal or other energy sources. Life-cycle accounting also fails to recognize that, if incentives are given for ethanol producers to use relatively "clean" inputs (like natural gas), the "dirtier" inputs (like coal) that might otherwise have been used for the ethanol production simply will be used by other producers to make products that are not covered by the sustainability standard. Thus, sustainability standards reshuffle who is using what inputs--with no net reduction in national emissions.

Finally, sustainability standards are discriminatory under World Trade Organization law and are unlikely to survive a legal challenge from ethanol producers abroad. The U.S. will not be able to rely on the World Trade Organization's exception for trade laws protecting the environment because of lax U.S. policies dealing with greenhouse gas emissions relative to its wading partners. Moreover, the imposition of U.S. tariffs on more climate-friendly ethanol produced abroad weakens any U.S. defense of ethanol sustainability standards under the WTO.

The biofuel market is in turmoil over sustainability standards, however, because the Environmental Protection Agency and the European Union are overdue in adjusting existing greenhouse gas emission rides. These rules are based on life-cycle accounting (LCA), a "well-to-wheel" measure of greenhouse gas emissions in the production of gasoline (diesel) and an analogous "field-to-fuel-tank" measure for ethanol (and biodiesel) production. The current controversy revolves around the effects of indirect land use changes and whether they should be included in the LCA measures. The choice of a sustainability standard for biofuels is deemed a crucial environmental policy decision and the debate has reached a fever pitch.

This Q&A demonstrates that sustainability standards based on LCA--with or without the consideration of indirect land use changes--will be, at best, ineffective and, accordingly, will provide little guidance to policymakers. Worse still, it can be misleading while at the same time serving to divert attention away from more important biofuel policy issues like tax credits, import tariffs, adding tax credits to mandates, and production subsidies for either the feedstock or the biofuel.

How can ethanol be "sustainable" in the first place? There is a scientific law akin to the law of thermodynamics: the C[O.sub.2] sequestered in growing the crop used for biofuel production is exactly offset by the C[O.sub.2] emitted when the automobile combusts the biofuel. Ethanol therefore is a "net zero" in C[O.sub.2] emissions, just like the production and consumption of other corn products, like bourbon. (Henceforth, we will use "bourbon" as a catchall term for all products other than biofuels that are produced from corn and other crops.) Some uses of land are net positive from a greenhouse gas perspective (e.g., forests, which sequester and store CO:), while others are net negative (parking lots). Yet, if you bum a fossil fuel (oil, natural gas, or coal), 100% of the carbon in that fuel is emitted, nearly all of it as carbon dioxide.

Why have a sustainability standard on biofuels when they are a net zero in C[O.sub.2] emissions? There should be none. There is no logic in having a sustainability standard for ethanol (or a...