Growth Energy respectfully submits these comments on the Environmental Protection Agency’s Workshop on Biofuel Greenhouse (GHG) Gas Modeling.
Growth Energy is the world’s largest association of biofuel producers, representing 89 biorefineries that produce nearly 9 billion gallons annually of low-carbon renewable fuel and 100 businesses associated with the biofuel production process.
Growth Energy appreciates EPA’s facilitation of the Workshop on Biofuel Greenhouse Gas Modeling (Workshop) and the knowledgeable presentations from government, academicians, and other stakeholders over the two-day program. It is critical that EPA move forward expeditiously in updating its 2010 lifecycle analysis (LCA) of ethanol given how outdated that analysis is and the advancements in modeling since 2010. EPA substantially undervalues the GHG emissions benefits of ethanol due to its failure to update its methodology for assessing lifecycle GHG emissions. Specifically, over a decade ago, EPA projected that lifecycle GHG emissions from corn ethanol would be only 21% better than the representative 2005 baseline for petroleum lifecycle GHG emissions, but the best available and most recent science–including studies published by the DOE’s Argonne National Laboratory and USDA–place the lifecycle GHG reductions from corn ethanol in the range of 39-46% below the petroleum baseline. These results are bolstered by other studies, including the expert analyses of Environmental Health & Engineering, Inc. (EH&E) and Life Cycle Associates, LLC attached to this comment letter and included in Growth Energy’s comment letter on the reset rulemaking.2
As explained below, it is also important that EPA not rely on a fundamentally flawed recent
study of ethanol’s lifecycle GHG emissions that uses improper assumptions and unreliable
modeling to assert demonstrably incorrect findings related to ethanol’s GHG emissions.
Updating the LCA of ethanol is critical not only to faithfully implementing the
Renewable Fuel Standard (RFS) program (the only Clean Air Act program explicitly aimed at
reducing GHG emissions), but for sound policymaking on a range of future potential
rulemakings designed to facilitate the use of E15, flex fuel vehicles, higher-level ethanol blends
like E85, and sustainable aviation fuel (SAF). Robust and accurate cost-benefit analyses depend
on accurate assessment of the GHG impacts of biofuels, particularly given this Administration’s
use of the social cost of carbon (SCC) to monetize the societal benefits of projected GHG
emission reductions and the associated avoidance of incremental damages from climate change.
Further, an updated LCA is necessary to achieving the Administration’s ambitious
climate goals. The President has declared that climate change poses an “existential threat” and
established national goals of realizing a 50-52% reduction in GHG emissions by 2030 and net1
Workshop on Biofuel Greenhouse Gas Modeling, https://www.epa.gov/renewable-fuel-standardprogram/workshop-biofuel-greenhouse-gas-modeling.
2 See Scully, et. al., Carbon intensity of corn ethanol in the United States: state of the science (2021)
(showing reduction of 46%); Lee, et. al., Retrospective analysis of the U.S. corn ethanol industry for
2005–2019: implications for greenhouse gas emission reductions (2021) (showing reduction of 44%%);
Rosenfeld, et. al. A Life-Cycle Analysis of the Greenhouse Gas Emissions from Corn-Based Ethanol
(Sept. 5, 2018) (showing reduction of 39%).
zero emissions by 2050.3
As the largest contributor to U.S. GHG emissions, the transportation
sector must play a major role if these goals are to be achieved. Moreover, projections from the
International Energy Agency, the U.S. Energy Information Agency, and Bloomberg agree that
liquid fuels will retain a major share of transportation sector energy demand for at least the short
and medium term.4
The fact is that liquid fuels will be needed to keep the American
transportation system running for the foreseeable future. It is therefore impossible to achieve the
Administration’s climate goals in the transportation sector without harnessing the full potential
of biofuels to substitute for the petroleum that will otherwise dominate the liquid fuels market for
years to come.
EPA has highlighted that the “impacts of climate change are affecting people in every
region of the country, threatening lives and livelihoods and damaging infrastructure, ecosystems,
and social systems in communities across the nation.”5
Failure to utilize all available pathways
of reducing carbon emissions increases the likelihood of “climate disaster” with “devastating”
impacts, particularly on the most vulnerable communities.6
Choosing to leave the GHG
emissions reductions benefits of biofuels on the table would be such a failure. EPA must
accurately account for the GHG lifecycle benefits of renewable fuels and appropriately
incentivize production and use of these fuels consistent with the RFS’s mandates.
In February, Growth Energy submitted a comprehensive 643-page comment on EPA’s
proposed RFS Program Annual Rule for 2020-2022.7
A large portion of this submission was
dedicated to providing information to aid EPA in its development of an accurate, updated LCA
value for ethanol that is based on and consistent with the best available science. Specifically, an
analysis of the literature demonstrates that the best available science has coalesced around a
credible range of indirect land use change (iLUC) values that are substantially lower than EPA’s
2010 projections. This downward trend in iLUC estimates is attributable to improvements in the
model’s methodologies, designs, data, and parameters, including the (1) addition of new modules
that allow for more accurate simulation of real-world agricultural practices; (2) addition of more
spatially resolved information on land cover; and (3) tuning of parameters that describe rates of
land conversion and land. Factors other than iLUC have also contributed to the decrease in LCA
3 See Exec. Order 14008, Tackling the Climate Crisis at Home and Abroad (Jan. 27, 2021); Remarks by
President Biden Before Signing Executive Actions on Tackling Climate Change, Creating Jobs, and
Restoring Scientific Integrity, White House Briefing Room (Jan 27, 2021),
https://www.whitehouse.gov/briefing-room/speeches-remarks/2021/01/27/remarks-by-presidentbidenbefore-signing-executive-actions-on-tackling-climate-change-creating-jobs-and-restoringscientificintegrity/ (“I’m signing today an executive order to supercharge our administration ambitious plan to
confront the existential threat of climate change. And it is an existential threat.”).
4 See Section II-A-3 of Growth Energy’s Comment on EPA’s Proposed RFS Annual Rules for 2020-2022
(Feb. 4, 2022), Comment ID # EPA-HQ-OAR-2021-0324-0521, excerpts attached as Exhibit 1.
U.S. Environmental Protection Agency Policy Statement on Climate Change Adaptation (May 26,
2021), in U.S. Environmental Protection Agency Climate Adaptation Plan (Oct. 2021),
U.S. Dep’t of State, The Long-Term Strategy of the United States (Nov. 2021),
7 See supra note 4.
estimates, including reduced energy consumption of ethanol plants, reduced GHG intensity of
the U.S. electric grid, and increased utilization of ethanol co-products.
Since Growth Energy’s previous submission, the Biofuels GHG Workshop has furthered
scientific discussion on LCA analysis. In this comment and in multiple attached expert reports,
Growth Energy now addresses some of the issues raised by Workshop presenters.
First, we encourage EPA to closely review Argonne National Laboratory’s
multidisciplinary response to a deeply flawed study, Environmental Outcomes of the US
Renewable Fuel Standard by Lark, et. al. (“Lark, et al. 2022”), which was repeatedly mentioned
by certain presenters at the Workshop. Below we summarize key considerations from that
response as well as an additional analysis by EH&E of the Lark, et al. 2022 paper.
Second, Growth Energy also offers two additional expert reports to facilitate EPA’s
consideration of materials presented in the workshop and move expeditiously to updating
ethanol’s GHG LCA. Life Cycle Associates discusses the importance of accurate model
parameters and that updated models are reliable and accurate tools to incorporate real-world data
from the past decade into calculating a new LCA of ethanol. Net Gain Ecological Services (Net
Gain) provides recommendations of key areas for EPA to focus on as the Agency confronts both
the immediate task of accurately updating the LCA of biofuels and longer-term efforts to
improve scientific understanding of the environmental impacts of biofuel use. Each report is
briefly summarized below.
Finally, we offer comments on an appropriate approach to addressing uncertainty in GHG
lifecycle modeling, as addressed by EH&E in its report included with Growth Energy’s comment
letter on EPA’s proposed 2020-2022 RFS Annual Rule and provided for ease of reference again
here. Specifically, consistent with the interagency working group’s approach in the SCC
context, EPA should address the issue of uncertainty by utilizing central estimates, embracing
the principle of best available science, and updating its LCA for corn ethanol without undue
Nothing raised by the Workshop or published since February alters the fundamental
conclusions put forth in Growth Energy’s comprehensive comment on the EPA’s 2020-2022
proposed rule. EPA must swiftly update its lifecycle GHG emissions analysis for
conventional corn ethanol using the best currently available science. Through extensive
expert analyses submitted in comments both to the Workshop and the proposed RFS Annual
Rule for 2020-2022, EPA has the tools available to develop LCA values that incorporate the
many scientific and industry advancements that have been achieved since 2010. Continued delay
on this critical issue is contrary to the congressional purposes of the RFS Program, undermines
national climate goals, and leaves substantial GHG emissions reductions on the table.