Growth Energy Calls on DOE to Set the Record Straight on Anti-Ethanol Study

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March 16, 2022

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(Growth Energy) Growth Energy CEO Emily Skor sent a letter to U.S. Department of Energy (DOE) Secretary Jennifer Granholm calling on the department to address the most recent inaccurate and misleading study by Tyler Lark and others that claims to have been partially funded by the department.

The study directly contradicts conclusions from DOE’s own Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies (GREET) model, which has been tracking the impacts of corn-ethanol’s lifecycle emissions since 1996. Last May, DOE’s Argonne National Lab stated that, “for the United States, biofuels like corn ethanol can play a critical role in reducing our carbon footprint.”

“Failing to address this research’s inconsistencies and departure from mainstream science could have negative consequences in our nation’s quest to decarbonize the transportation sector—both on the ground and in the air. According to recent research by the Rhodium Group, our industry’s contributions in reaching net-zero emissions targets and decarbonizing the transportation sector will be necessary,” wrote Skor.

“The ethanol industry is continually finding new ways to innovate and reduce emissions throughout its production cycle, including by creating new applications for hard-to-decarbonize industries like aviation. We must rely on the best and most widely accepted science to achieve our climate goals and attain net-zero emissions by 2050.”

You can read the full letter here and more about the study here. This letter follows Growth Energy’s submission of supplemental comments on EPA’s proposed 2020, 2021, and 2022 Renewable Volume Obligations (RVOs), which further refute the Lark study’s erroneous and misleading claims. Read more about the supplemental comments here. READ MORE

Click here for a more detailed rebuttal from RFA that offers key facts about ethanol’s environmental impacts that were purposely omitted from the paper. READ MORE

Comments on “Environmental Outcomes of the US Renewable Fuel Standard” (Argonne National Laboratory)

Growth Energy Submits RVO Comments to Debunk Anti-ethanol Study (Growth Energy)

ACE Corrects Misrepresentations of RFS Environmental Outcomes (Biofuels Digest)

Setting the Record Straight on the Environmental Outcomes of the Renewable Fuel Standard (Renewable Fuels Association)

FOR THE RECORD: Biofuels trade group Growth Energy is calling on Energy Secretary Jennifer Granholm to “correct the record” (Politico's Morning Energy)

CORRECTING MISREPRESENTATIONS OF THE ENVIRONMENTAL OUTCOMES OF THE RFS (American Coalition for Ethanol)

Letter: Corn ethanol is the solution we need (Iowa State Daily)

How Corn Ethanol for Biofuel Fed Climate Change (Civil Eats)

Growth Energy submits RVO comments to debunk anti-ethanol study (Ethanol Producer Magazine)

Ethanol’s clean air benefits clouded by greenhouse gas emissions — Corn ethanol’s per-gallon carbon output shrinks, but greenhouse gas from plants remains high. (Star Tribune)

Here we go again: Is ethanol climate-friendly? (Farm Progress/Farm Futures)

Preliminary Rebuttal to PNAS Report: “Environmental outcomes of the U.S. Renewable Fuel Standard” (Lark et al.) (Renewable Fuels Association)

Environmental outcomes of the US Renewable Fuel Standard (Proceedings of the National Academy of Sciences)

Ethanol Less Green Than Gas, Study Funded by Biofuel Critics Says (Bloomberg)

Ag Policy Blog: Study Challenges GHG Benefits of Corn Ethanol and the RFS (DTN Progressive Farmer)

At bioenergy crossroads, should corn ethanol be left in the rearview mirror? (University of Wisconsin-Madison)

U.S. corn-based ethanol worse for the climate than gasoline, study finds (Reuters)

How Corn Ethanol for Biofuel Fed Climate Change (Civil Eats)

The Science Speaks for Itself on Biofuels, GHG Reductions and Land Use (Growth Energy)

Electric vehicles run over ethanol and gas (Reuters)

Mauren: Why are we still growing ethanol? (Iowa State Daily)

Ethanol isn’t as green as you might think, researchers say (Renewable Energy World)

New study casts doubt on ethanol’s climate benefits (The Hill)

RFA Refutes Latest Negative Study on the RFS (WNAX)

Corn ethanol no better—and probably worse—than burning gasoline, study says — Efforts to reduce carbon pollution using ethanol appear to have backfired. (Ars Technica)

ACE corrects misrepresentations of RFS environmental outcomes (Biofuels Digest)

Ethanol no better than gasoline, study finds; UW scientists seek better plant fuels (LaCrosse Tribune)

ADMIN STANDS BY BIOFUELS: (Politico’s Morning Energy)

Letter: Corn ethanol is the solution we need (Iowa State Daily)

Our Response to The Atlantic: The Truth about Ethanol, Energy Security and World Grain Supplies (Renewable Fuels Association)

Leading Researchers Contradict Hit Piece on Ethanol’s Environmental Impacts (Renewable Fuels Association)

Biofuels Are Getting a Second Look—and Some Tough Questions: Bioethanol has been touted as a green way to cut reliance on Russian oil. But new modeling suggests it isn’t the climate solution we’d hoped for. (Wired)

Biofuels: Why Growing Food for Fuel is a Foolish Choice (EarthJustice)

Turns Out Biofuels Aren’t All They Were Cracked Up to Be (Mother Jones (reprint of Wired article above)

A Myth-Buster’s Job is Never Done (Growth Energy/Ethanol Producer Magazine)

Politicians Are Touting Corn Ethanol as a Climate Solution. The Truth Is More Complicated (Time Magazine)

How green are biofuels? Scientists are at loggerheads -- Replacing gasoline with ethanol has changed landscapes across the globe. (Knowable Magazine/Ars Technica)

Excerpts from Biofuels Digest: Misrepresentations in Lark et al. 2022

Lark et al. estimated that “the RFS increased corn prices by 30% and the prices of other crops by 20%” which, in turn, expanded U.S. corn cultivation by 2.8 million hectares (8.7%) and total cropland by 2.1 Mha (2.4%) in the years following policy enactment (2008 to 2016)”.

Facts: Corn prices during the 5-year period of 2008 through 2012 averaged $5.40 per bushel and during the 4-year period of 2013 through 2016 averaged $4.35 per bushel. A 19% reduction (Chicago Board of Trade Monthly Futures Prices). The corn cultivated area increased 2.3% during these same time periods and total cropland cultivated area increased just 8 tenths of 1% (USDA databases).

Lark et al. estimated that 30-year emissions associated with RFS-induced conversions to cropland were 320.4 Tg CO2e, or approximately 181 metric tons of CO2 per hectare per year.

Facts: Grasslands and pasturelands contain about 150 metric tons per hectare of soil organic carbon in the top 3 feet of soil. If 100% of the carbon decomposed in the 3-foot layer of soil over a hectare, the total CO2 emissions would be 550 metric tons of CO2. Lark’s claim of 181 metric tons of CO2 per hectare per year implies that the entirety of soil organic carbon (SOC) in the top 3 feet of soil in converted cropland would decompose in only 3 years, and then corn ethanol is charged with 181 metric tons of CO2 emissions per hectare per year for another 27 years, even though Lark et al. claims the entire SOC stock will be decomposed after 3 years. Furthermore, soil scientists have determined that from about 1900 to 1950, grasslands that were converted to cropland lost about 50% of the original SOC in the top 8 inches of soil. This is an annual loss rate of .4 metric tons of C per hectare per year (1.5 metric tons soil CO2 emissions per hectare per year). Lark’s soil CO2 emission estimate of 181 metric tons of CO2 per hectare per year is more than 100 times the soil CO2 emission rate than was experienced during the first 5 decades of the past century. During the first 5 decades of the past century, grain and residue yields were very low resulting in an extremely negative crop/soil carbon balance. Modern corn production’s high grain/residue yields, along with reduced tillage intensity, result in a positive crop/soil carbon balance and thousands of well-managed corn fields are sequestering CO2 at the rate of .5 metric tons of CO2 per hectare per year.

Lark et al. claims that nitrous oxide emissions due to higher Nitrogen fertilizer use during corn production, and Land Use Change, results in a 9-gram CO2e per megajoule increase in corn production GHG emissions. A 9 gram per megajoule increase in corn production nitrous oxide emissions implies a 68% increase in nitrous oxide emissions on all corn production used for ethanol. This would also imply that nitrogen use rates on corn must have increased by 68%.

Facts: USDA fertilizer use data indicate that total Nitrogen (N) fertilizer use per bushel of corn production was .88 lbs N per bushel in 2010, .82 lbs N per bushel 2016, and .85 lbs per bushel in 2018. These data do not indicate dramatically higher nitrogen use or nitrous oxide emissions from N fertilizer use on corn.

Alverson poses the question: Why does Lark et al. use modeling to estimate biofuel GHG emissions? It is understandable to use modeling to estimate future impacts, but why use modeling when a track record of historical facts are available? “I think we know why,” Alverson says. “Modeling outcomes can be manipulated and biased by small changes in modeling factors.” READ MORE

Excerpt from Renewable Fuels Association: An important new assessment published by experts from the Department of Energy’s Argonne National Laboratory, Purdue University, and the University of Illinois system found major flaws in a recent paper that made unfounded allegations about the greenhouse gas benefits of ethanol compared to gasoline.

Responding to the report Environmental Outcomes of the US Renewable Fuel Standard, which was led by Tyler Lark of the University of Wisconsin, the authors stated, “After a detailed technical review of the modeling practices and data used by Lark et al., we conclude that the results and conclusions provided by the authors are based on several questionable assumptions and a simple modeling approach that has resulted in overestimation of the GHG emissions of corn ethanol.”

Renewable Fuels Association President and CEO Geoff Cooper responded to the release of the assessment. “It has been well established that ethanol reduces greenhouse gas emissions by roughly half compared to gasoline. Unfortunately, a recently published report that attacked ethanol made headlines despite its obvious errors,” said Cooper. “Now that light has been shown on these flaws, we call on the news media to correct the record—particularly those who were so quick to report this now thoroughly debunked attack. Ethanol is a renewable, domestically produced fuel that is lower in cost and lower in carbon than gasoline. Today more than ever, it’s also vital for energy security.”

A number of problems with the study by Lark et al. were pointed out, including:

The land-use changes identified by Lark et al. likely reflect the conversion of fallow or idle land to crops rather than permanent grasslands.
Lark et al. likely overestimated soil organic carbon (SOC) loss by a factor of two to eight as a result of the incorrect application of carbon response functions. The authors noted that “the validation of the SOC emissions model used by Lark et al. … showed remarkably poor fit to measured SOC changes.” This is important, since a foundational assertion in the recent study was that emissions related to land-use change are higher than commonly recognized.
Lark appeared to have double-counted the emissions of nitrous oxide—a greenhouse gas—from the use of fertilizer in corn production by adding them in while overlooking the fact that they are already included in the corn-farming-related emissions in the main lifecycle assessment models.
Lark attributed 5.5 billion gallons of ethanol per year to the expanded Renewable Fuel Standard (RFS2) between 2008 and 2016 by comparing the volume under RFS2 and RFS1 without considering other significant drivers of ethanol production.
The validity of picking the limited time period of 2006-2010 to assess price impacts associated with RFS2 is questionable. This does not align with the 2008-2016 timeframe for the study by Lark et al., and significant price increases occurred during this period.

When the Lark paper was first published, RFA posted a preliminary rebuttal of the effort and noted in a blog post that the association had tried to work with Lark, but to no avail. “We asked how we could work together to ensure their error-ridden satellite analysis of land-use changes was grounded in reality,” Cooper wrote. “We never heard back from them. RFA is always open to having an honest, fact-based discussion about the impacts of ethanol and the RFS on the environment and economy.” READ MORE