Policy and perspective: The scoping plan for AB 32, and how to do it right

Science can be precise but inaccurate, resulting in wonderfully precise yet completely misguided results from a policy perspective. Similarly, econometrics modeling can paint a picture with a limited, narrow range of possibilities (aka “low standard deviation”) with a significant mistake around the mean value (“high standard error”). In the debate ranging about biofuels today, both problems persist in different manifestations – among the recent papers influencing current debate (especially around the AB32 scoping plan being considered in California) are articles by Professor Timothy Searchinger1 arguing that biofuels harm carbon emissions more than they help, and a recent letter2 by a group of distinguished academics (Delucchi et al) arguing for strong consideration of biofuels’ indirect land use change (iLUC) in the development of California’s Low Carbon Fuel Standard. Both are ground in solid science, well‐ intentioned pieces that are intended to inform the debate – unfortunately, both fall into the trap of inaccurate modeling nonetheless conducted to a high degree of precision; they provide a false sense of knowledge to the debate that can mislead policy making. My focus here is on explaining why they are wrong for the intended purpose of policy making, and to illuminate more important issues they fail to consider, besides having model input assumptions that are both likely to be wrong as currently used and that can be dramatically changed by policy signals…

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