The debate about biofuels has always been painted with a wide brush and bounced between extremes. One week there's a report that says crop A or conversion technology B is promising and everyone is gaga; the next week, some new study how to do biofuels wrong grabs the spotlight and there's nothing but dire predictions and "I told you so."
The Searchinger et al. paper in Science two weeks ago seems to be a different beast. The scale of the impacts predicted are huge, they attach to any biomass that diverts arable land away from food, feed, or fiber production, and they were, even before the study hit the streets, squarely in the sights of federal and California regulators. So while many of the discussions I've had about emissions from land-use change and biofuels have had a feeling of college econ 101 study sessions, the debate is not academic.
My friend, Ruth Scotti, who works in the biofuels industry, put the challenge of processing the Searchinger analysis well when she asked: what's the truth, what can be measured, and what's important? Paraphrasing and mixing in some of my own thoughts, the truth is underlying supply and demand dynamic. As I said last time, I see this as undeniable. What can be measured is a much trickier question, but the critical one at this juncture. I was alarmed to hear today that the predictive validity of very few, if any, economic models are tested with back-casting. This is a process of putting in old data and seeing if the model accurate predicts some historic period. Back-casting is used regularly to evaluate climatic models. The human element makes economic system less predictable, but not random. There are at least three models being used to look at land-use impacts of biofuels--Iowa State's FAPRI, Texas A&M's FASOM, and Perdue's GTAP. In short order, it will be important to run these models with similar inputs and to test them with some type of back-casting.
The question of what is important has already been answered in CA with the low-carbon fuel standard and at the federal level through the renewable fuel standard with its lifecycle GHG emissions standards and land-use safeguards. As my colleague Roland and I have written about, a federal low-carbon standard is a critical next step to further focus on what's really important--reducing the global warming pollution associated with our transportation sector.
Two concerns that spent some time thinking through are the fairness of regulating indirect land-use emissions and novelty of including these type of emissions in regulations. Ultimately, I disagree that including the dynamic of indirect land-use in regulations is unfair or unprecedented. Especially while we still do not have international protocols that pay to protect or simply prohibit clearing of carbon rich lands, emissions from cleared land driven by marginally higher demand is simply a function of the laws of supply and demand. Just as giving a gun to a person you know to be crazy makes you criminally liable for that person's actions with that gun, we as a country must take responsibility for production (agricultural or manufacturing for that matter) we effectively export to countries that are not protecting their carbon rich lands. Furthermore, we assume supply and demand to hold true when we allocate lifecycle emissions from ethanol production to co-products.
Nor is this the only example of calculating second order impacts. Most modeling of the impacts of CAFE increases (including that done within NRDC) does include second order economic impacts. We model the effective lower price per mile of a more efficient vehicle causing more vehicles-miles-traveled. For every 10% lower cost of driving, our model assumes a 1% increase in the miles driven. This “take-back” or “rebound” effect is also common to models of savings from more efficient appliances. Similarly, there are many instances of regulations factoring second order impacts. For instance, NOx and VOC are regulated both for their direct impacts and because they cook into ozone.
Finally, options such as cover crops, ag residues, and new crops that produce more feed, food, fiber and biomass for fuel that there much that farmers can do to minimize these impacts. We should be working to make sure that these practices have the highest economic return for farmers not trying to deny the impacts of more business as usual.