December 29, 2009

Can regulations be based on an estimate?

The Nebraska Corn Board's Kelly Brunkhorst (@kbrunkhorst) recently spent some time reviewing the California Air Resources Board (ARB) low carbon fuel standard. (For background, click here and here.)

The timing was perfect because a lawsuit was recently filed against California's ARB for the standard. The suit was filed in the Federal District Court of Fresno by the Renewable Fuels Association and Growth Energy, charging that the measure violates both the Supremacy Clause and the Commerce Clause of the U.S. Constitution.

You can read more about the suit over at Corn Commentary.

In either case, Brunkhorst's thoughts are below - and he raises an important point.

Can regulations be based on an 'Estimate'?

Wikipedia defines “estimated” to mean a calculated approximation of a result which is usable even if input data may be incomplete or uncertain. But my question is…can an estimated figure be used to write state or Federal regulations when the science is incomplete and/or uncertain? For that matter can “approximation” be used as a basis for regulations.

Currently the state of California is in the final stages of adopting a Low Carbon Fuel Standard that provides a plan in which to reduce transportation greenhouse gas emissions by 10% by 2020. This is an admirable task and goal, but the avenue in which they are proceeding, sure seems to be filled with holes and unanswered questions.

In order to come up with a carbon intensity figure, the California Air Resources Board (CARB) is utilizing the modified GREET model. This model was initially developed by the staff at Argonne National Lab, but was modified by staff at CARB to better fit the California environment.

But in addition to the GREET model, CARB says that significant indirect effects such as land use change (LUC) must be included in the final carbon intensity score. To do this, CARB is utilizing the GTAP model to “estimate” this figure. Yes, “estimate” and this figure is being used in the regulation. Look on page 5 of the corn ethanol pathway, version 2.1 that can be found at CARB’s website (.pdf). To quote the paper exactly it states, “The GTAP model has been used to estimate Land Use Change impact for corn ethanol and is estimated to be 30 g CO2e/MJ.”

The whole land use change science is so uncertain, over 100 scientists have written a letter (.pdf) to CARB on this basis. In fact the very models that are being used to “estimate” land use change were not initially developed for this use.

So I guess to answer the question, you have to say yes, but it is very unfortunate that estimates can be used to base regulations on. Whatever happened to sound science and facts?

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