This memorandum provides Net Gain’s preliminary observations regarding Environmental Outcomes of the US Renewable Fuel Standard published by Lark et al. (2022). The work described in this paper appears to be the same as that presented at an American Association for the Advancement of Science meeting on February 15, 2019. The August 2019 Ramboll report previously submitted to the docket for this rulemaking as part of Growth Energy’s comment letter (ID: EPA-HQ-OAR-2021-0324-0521) discusses the presentation material at Section 3.4. We briefly summarize below a few key issues with the study’s attribution of adverse environmental impacts to the Renewable Fuel Standard (RFS) based on a preliminary, limited review. These include:
- The study importantly neglects to evaluate the relationship between oil prices and corn prices.
- The study fails to adequately explain and evaluate uncertainties associated with its use of a “Business as usual” scenario absent the RFS as a counterfactual.
- With respect to land use change modeling, the study purports to correct for grave deficiencies in one of the author’s prior work by applying “recommended practices,” but does not explain how those practices were applied. Further, it is not possible to evaluate some of the data sets themselves as they are non-public, thus limiting third party reviewers’ abilities to evaluate the validity of the conclusions the authors draw.
- The authors characterize as fact numerous modeled results, giving the reader a misleading impression of false confidence in the conclusions which are drawn from highly uncertain models embedded with extensive assumptions that may or may not reflect the real-world.