ACE to EPA: Adopt GREET Model and Recognize Ethanol’s Low Carbon Value

April 04, 2022

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by Helena Tavares Kennedy (Biofuels Digest) In South Dakota, The American Coalition for Ethanol submitted feedback to the Environmental Protection Agency’s request for comment on the current scientific understanding of greenhouse gas modeling of land-based crop biofuels.

ACE CEO Brian Jennings and ACE Board Director Ron Alverson contributed to the feedback after attending EPA’s workshop on biofuel GHG modeling. The comments cover subject areas that illustrate why EPA must update the methodology it uses to account for the lifecycle GHG emissions of ethanol and other biofuels to properly credit their GHG benefits to meet climate goals.

The topics covered include: the role corn ethanol can play in combatting climate change; land use change discrepancies, along with research that debunks the flawed Lark et al. study findings and the mythical tie between ethanol and food price increases; why GREET is the gold standard modeling tool and should be adopted by EPA; how efficient use of fertilizer is reducing nitrous oxide emissions; and soil carbon sequestration advances through climate-smart farming. The comments conclude by detailing a first-of-its-kind pilot project ACE is leading to convince market regulators and lifecycle modelers to provide carbon credits for certain farming practices. READ MORE

Docket No. EPA-HQ-OAR-2021-0921-0001 -- Request for Comments on the Current Scientific Understanding of Greenhouse Gas Modeling of LandBased Crop Biofuels (American Coalition for Ethanol)

RFA to EPA: Use Current Data and GREET Model to Update Corn Ethanol GHG Analysis (Renewable Fuels Association)

COMMENTS OF THE RENEWABLE FUELS ASSOCIATION (RFA) IN RESPONSE TO THE EPA WORKSHOP ON BIOFUEL GREENHOUSE GAS MODELING DOCKET ID NO. EPA-HQ-OAR-2021-0921 (86 Fed. Reg. 73757) (Renewable Fuels Association)

Groups urge EPA to adopt GREET, improve GHG modeling of biofuels (Ethnaol Producer Magazine)

Excerpt from American Coalition for Ethanol: Corn Ethanol is Part of the Solution to Address Climate Change

ACE members firmly believe corn ethanol and other biofuels need to be a meaningful part of the solution to achieving these important climate goals. In fact, during its fourth quarter meeting of 2021, the ACE board of directors unanimously adopted the following resolution to compliment the administration’s climate goals: “The ACE Board of Directors supports the adoption of policies at the state and/or federal level which recognize ethanol is part of the climate and health solution while crediting farmers and ethanol producers for activities which will help ethanol reduce lifecycle GHG emissions by at least 70% on average compared to gasoline by 2030, and reach net-zero lifecycle GHG emissions by 2050.”1

In order to realize the goal of net-zero GHG emissions by midcentury, the U.S. will need to implement a policy framework to increase the use of low carbon biofuels such as corn-based ethanol which can displace fossil fuels. We acknowledge the administration heavily favors the use of electric vehicles (EVs) to decarbonize the transportation sector, but this overlooks the power grid realities that cause many EVs to have significant lifecycle GHG emissions and the practical reality that it will be impossible to electrify the entire transportation sector. In 2021 the Rhodium Group released a compelling report indicating even under most aggressive sales projections, EVs alone will not accomplish the goal of the Biden administration to reach net-zero emissions by 2050.2 Rhodium explained that increased reliance of clean fuels (and efficiency standards) will be needed to close the emissions gap. In order to properly account for the climate benefits of land-based crop biofuels that we will rely upon to help meet climate goals, it is past time for EPA to finally update the methodology it uses to account for the lifecycle GHG emissions of ethanol and other biofuels.

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The Harvard/Tufts study found that average corn ethanol reduces GHGs by 46 percent compared to gasoline and given improvements occurring in corn farming and within ethanol facilities, corn ethanol’s carbon footprint will continue to decline over time.

EPA’s Assessment of Land Use Change is Far Overstated

Land use change represents one of the most glaring discrepancies between EPA’s outdated approach to lifecycle modeling and more recent versions of the GREET model as well as other research on this topic.

We recognize there will be a degree of uncertainty about actual land use change, and each model will result in variability based on methodologies used, but recent and comprehensive modeling and research on land use indicates it is far past time for EPA to update its assessment.

EPA’s outdated modeling used in the final RFS rule (in 2010) assigns an enormous land use change penalty of 29 grams to the overall carbon intensity (CI) of corn ethanol, as illustrated in the chart on page 3. Subsequent and more sophisticated research on land use change, in addition to the fact that the U.S. has produced more than 15 billion gallons of corn ethanol so actual land use changes can be observed, indicates a more accurate land use factor between 3.78 and 7.5 grams, as illustrated on the far right of the graph using recent versions of the GREET model.

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Even the California Air Resources Board (CARB), in its implementation of the Low Carbon Fuel Standard (LCFS), has reduced the corn ethanol land use change assumption from the 30-gram penalty it originally applied based on a 2009 assessment with a 19.8-gram factor today based on an assessment it did in 2015. While the 19.8-gram land use change penalty is still inexplicably higher than what most research suggests should be the case, the fact remains CARB has at least tried to update their land use emissions related to corn ethanol while EPA has not.

Recent Lark et al. Paper Wildly Overstates Land Use Change

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One of the most definitive analyses done on this topic was published in the Biomass and Bioenergy Journal by D.S. Shrestha et al. in 2019.8 According to the abstract (emphasis added): “Food price and land use data over an extended time period have been examined to identify possible correlations between biofuel production and food price or land use changes. We compared the food price index before and after the biofuel boom in the 2000s to evaluate biofuel’s impact on the inflation rate. We found that the U.S. food price inflation rate since 1973 could be divided into three distinct regions. The inflation was lowest at 2.6% during 1991-2016, which encompasses the biofuel boom. Among many factors, continuously rising food production per capita was identified as the likely cause of low food price inflation during this period. The U.S. exports of corn have not declined since the 1990s and soybean exports are rising at a steady rate. Among several variables tested as a cause of food price index increase, crude oil price had the highest correlation.

We also manually verified the automated land use classification of satellite image covering 664 km2 in three selected areas in the U.S. We found that 10.9% of nonagricultural land was misclassified as agriculture, whereas only 2.33% of agricultural land was misclassified as non-agriculture. The automated classification showed an 8.53% increase in agricultural land from 2011 to 2015, which the manual classification showed only 0.31% increase. This result was within the margin of error alluding to no significant land use change. We concluded that automated satellite image land use classification should be verified more rigorously to be used for land use change
analysis.”

Since we are in a period where crude oil prices are high again due to geopolitical unrest and there are concerns about inflation in general and food prices specifically, we know EPA will be under enormous pressure from certain groups to blame biofuel production for food price increases and to bake this faulty assumption into future GHG modeling of biofuels. We strongly encourage the Agency to heed this finding from Shrestha et al. on the issue of biofuels and food prices (emphasis added): “Globally, it was found that the food price index had highest correlation with crude oil price and 96% of the variability could be explained from the crude oil price and world population. Looking at the discrepancies between model predictions and observed data, we concluded that the assumptions in economic models predicting the impact of biofuel on food prices and indirect land use change needs to be revised, and carefully assessed to see if the model captures the complex real-world dynamics adequately by validating the results against real-world data.”

Finally, knowing there was considerable discussion of satellite images for estimating land use change during the EPA workshop held earlier this year, we share the conclusion from Shrestha et al. (emphasis added): “Based on our findings, it was concluded that satellite analysis is not an accurate method of determining land use change. In summation, our findings indicate that there has been no significant change in U.S. food prices due to biofuels and biofuels have not caused any significant agricultural land use change. We conclude that machine classified satellite images do not have needed accuracy yet to be used for land use change analysis.”

The fact that USDA’s Cropland Data Layer (CDL) was never intended to be a tool for measuring land use change should be sufficient justification for dismissing the inaccurate “conclusions” from Lark et al., and to be clear, many papers have been published over the years to explain why the CDL should not be used to determine land use change. We refer EPA to but a handful of those reports.9 10 11

GREET is the Gold Standard Model and Should be Adopted by EPA In response to EPA’s questions about what model(s) are available to evaluate the lifecycle GHG emissions of land-based biofuels, and what model(s) meet the Clean Air Act requirements for quantifying the direct and indirect emissions of biofuels, the GREET model is the global gold-standard and should be EPA’s model of choice. Unlike EPA’s badly outdated 2010 assessment, the assumptions and estimates used by Argonne scientists in GREET are under constant peer review and updates to the model occur annually.

Not only do more than 40,000 users around the world depend upon GREET to help determine the lifecycle GHG impacts of certain fuel technologies, but the model is the basis for the assessments used under the California LCFS and Oregon Clean Fuels Program. Legislation pending in Minnesota to create a clean fuel standard would statutorily require the use of the latest GREET model.12

A considerable portion of EPA’s workshop on the GHG modeling of biofuels was devoted to uncertainty.

ACE encourages EPA to look for ways to minimize uncertainty surrounding the modeling of biofuel GHG emissions where possible, but we strongly encourage the Agency to recognize models cannot, nor are they designed to, answer all questions definitively. EPA should not dwell on uncertainty or allow a particular researcher’s opinion of what is “perfect” be the enemy of the real good the Agency can do by updating its assumptions about the GHG emissions of ethanol and by specifically choosing to adopt the gold-standard model for this purpose: the latest GREET model. We also implore EPA to recall that leading up to its promulgation of the final rule for the RFS, Searchinger et al. made extraordinary allegations about the potential land use and deforestation impacts of producing 15 billion gallons of corn ethanol in the U.S. However, as time went by, more advanced analyses and actual observations of land use changes showed that crop yields and crop switching in fact occurred instead of massive land use and deforestation changes, leading to lower and more accurate estimates of land use change emissions.

While it is an inconvenient truth for some, today’s corn ethanol meets the definition of an “advanced biofuel” under the RFS, notwithstanding the politically driven discrimination clause in the statute excluding “corn starch” ethanol from qualifying as an advanced biofuel under the program. According to the latest GREET model, average corn ethanol reduces GHG emissions by 50 percent compared to gasoline. In other words, we do not need to wait for so-called next generation crops or biofuels, or EVs and an entirely new supply chain to support them, to immediately begin tackling climate change. The GREET model is likely to be updated soon to account for the increased adoption of reduced tillage corn production, enhanced efficiency fertilizer use, and soil carbon sequestration from corn. When the GREET model reflects these updates, corn ethanol will get credit for reducing GHG emissions by between 60 and 70 percent compared to gasoline.

The lifecycle GHG emissions of corn ethanol can be divided between corn farming activities and the ethanol production process. Many ethanol producers have invested in technology to reduce CI within their facilities, but future progress on the ethanol production side is likely to be incremental. On the other hand, corn production holds the greatest potential for meaningful GHG improvements in the future. For example, practices to apply nitrogen fertilizer more efficiently and minimize N2O emissions provide nearterm opportunities to reduce farm-level GHG emissions attributed to the lifecycle CI of ethanol.

Additionally, tillage practices fostering enhanced soil carbon sequestration should result in a credit to offset or further reduce corn production GHG emissions.

Efficient Use of Fertilizer is Reducing Nitrous Oxide Emissions from Corn Production

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Soil Carbon Sequestration from Climate-Smart Farming

USDA has indicated agriculture can play an important role in mitigating climate change through soil carbon sequestration, which the department identifies as “among the best options for carbon storage in terrestrial ecosystems,” and estimates that U.S. farmers already store 20 million metric tons of carbon per year. USDA forecasts that agriculture could store an additional 180 million metric tons per year, representing an estimated 12-14 percent of total U.S. carbon emissions annually.

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Ultimately, the combination of climate-smart farming practices, constant improvements and efficiencies within ethanol facilities, and carbon capture and sequestration (CCS) puts corn ethanol on a trajectory to reach both net-zero and net-negative emissions – a trajectory that is unique to ethanol and squarely puts farmers and biofuel producers in a position to be a meaningful part of the solution to climate change.

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1 Motion adopted by American Coalition for Ethanol Board of Directors on November 10, 2021.
https://ethanol.org/ethanol-essentials/low-carbon-benefits-of-corn-ethanol

2 Closing the Transportation Emissions Gap with Clean Biofuels. January 15, 2021. https://rhg.com/research/closingthe-transportation-emissions-gap-with-clean-fuels/

3 The Case for Properly Valuing the Low Carbon Benefits of Corn Ethanol. (2018) https://ethanol.org/ethanolessentials/low-carbon-benefits-of-corn-ethanol

4 https://greet.es.anl.gov

5 https://ethanol.org/news/news/2021/01/26/new-study-showing-corn-ethanol-reduces-carbon-emissions-by-nearly-50-percent-cites-ace-low-carbon-white-paper/

6 Lark, T.J., Hendricks, N.P., Smith, A., Pates, N., Spawn-Lee, S.A., Bougie, M., Booth, E.G., Kucharik, C.J., and Gibbs, H.K., 2022. Environmental Outcomes of the U.S. Renewable Fuel Standard.

7 Farzad Taheripour, Steffen Mueller, Hoyoung Kwon, Madhu Khanna, Isaac Emery, Ken Copenhaver, and Michael Wang, 2022. Comments on “Environmental Outcomes of the U.S. Renewable Fuel Standard.”

8 D.S. Shrestha, B.D. Staab, and J.A. Duffield. (2019). Biofuel Impact on Food Prices Index and Land Use Change.
https://doi.org/10.1016/j.biombioe.2019.03.003

9 Dunn, Mueller, and Eaton. Comments on Cropland Expansion Outpaces Agricultural and Biofuel Policies in the U.S. April 29, 2015

10 Reitsma, Clay, Clay, Dunn, and Reese. Does the U.S. Cropland Data Layer Provide an Accurate Benchmark for
Land-Use Change Estimates? January 14, 2016

11 Wang, Wander, Mueller, Martin, and Dunn. Evaluation of Survey and Remote Sensing Data Products Used to
Estimate Land Use Change in the United States: Evolving Issues and Emerging Opportunities. Environmental Science and Policy Journal. December 2021.

12 https://www.house.leg.state.mn.us/bills/Info/HF2083/92/2021/0

13 “Estimating Net Carbon Emissions and Agricultural Response to Potential Carbon Offset Policies”. http://agris.fao.org/agris-search/search.do?recordID=US201500052566

14 https://onlinelibrary.wiley.com/doi/10.1111/gcbb.12631

15 https://www.usda.gov/sites/default/files/documents/LCA_of_Corn_Ethanol_2018_Report.pdf

16 https://iopscience.iop.org/article/10.1088/1748-9326/ab794e

Excerpt from Renewable Fuels Association: More broadly, the principles of lifecycle analysis (e.g., ISO 14040) require that consistent analytical boundaries be used when evaluating and comparing the relative attributes of competing products. It is inarguable that all forms of energy have associated indirect economic effects, many of which have implications for a fuel’s lifecycle GHG emissions. Thus, assuming the EPA includes ILUC in LCAs for biofuels, the Agency must also take into account the additional emissions that petroleum-based fuels induce through indirect economic effects at the resource margin. Otherwise, a comparison of GHG emissions from biofuels and petroleum-based fuels would not be on an “apples-to-apples” basis. Still, regulators should only quantify indirect effects in a manner that is scientifically defensible and driven by consensus-based methods.

2 Lee, U., Kwon, H., Wu, M. and Wang, M. (2021). Retrospective Analysis of the U.S. Corn Ethanol Industry for
2005–2019: Implications for Greenhouse Gas Emission Reductions. Biofuels, Bioprod. Bioref.
https://doi.org/10.1002/bbb.2225