USDA report: Ethanol greenhouse gas emissions much lower than gasoline

Source: By Donnelle Eller, Des Moines Register • Posted: Friday, January 13, 2017

Corn ethanol releases 43 percent fewer greenhouse gases than gasoline, making the renewable fuel greener than the federal government initially estimated, a study released Thursday by the U.S. Department of Agriculture shows.

Corn ethanol carbon emissions could drop to about half of gasoline’s by 2022 with improvements in corn yields and shifting fuel used during production, the report said. And added conservation practices would make corn ethanol 76 percent greener than gasoline over the next six years.

The federal government had previously estimated corn ethanol has 21 percent fewer greenhouse gas emissions than gasoline. Carbon dioxide and other greenhouse gases get trapped in the atmosphere and contribute to climate change and global warming.

“This report provides evidence that corn ethanol can be a GHG-friendly alternative to fossil fuels, while boosting farm economies,” said Agriculture Secretary Tom Vilsack, Iowa’s former governor.

The new estimate is significant because some scientists have long questioned whether ethanol is as environmentally friendly as supporters claim. Scientists interviewed Thursday questioned the accuracy of the new estimate.

The report found greater greenhouse benefits from corn ethanol than earlier studies because it factored in improvements in ethanol production, “from the corn field to the ethanol refinery,” the Agriculture Department said.

“Farmers are producing corn more efficiently and using conservation practices that reduce GHG emissions, including reduced tillage, cover crops and improved nitrogen management. Corn yields are also improving,” climbing more than 10 percent between 2005 and 2015, the agency said.

The news comes as Iowa renewable fuel supporters express concern about the Trump administration’s support for the Renewable Fuel Standard, the federal mandate requiring that ethanol and biodiesel be blended into the nation’s fuel supply.

President-elect Donald Trump, who supported ethanol during his campaign, nominated two RFS opponents to key agencies: Former Texas Gov. Rick Perry is slated to lead the Energy Department, and Oklahoma Attorney General Scott Pruitt is tapped for the U.S. Environmental Protection Agency.

Trump still has not named a new agriculture secretary.

Iowa is the nation’s largest corn and biodiesel producer, both of which set records last year. And the state led the nation in corn production last year at 2.74 billion bushels and was second only to Illinois in soybean production with 571.7 million bushels, a USDA crop production report showed Thursday.

The USDA’s ethanol report showed the nation’s ethanol production increased significantly between 2005 and 2015 — from 3.9 billion gallons to 14.8 billion gallons per year.

“At the same time, advances in ethanol production technologies, such as the use of combined heat and power, using landfill gas for energy, and co-producing biodiesel helped reduce GHG emissions at ethanol refinery plants,” the agency said.

“This USDA report clearly demonstrates what we have known for years — that biofuels like ethanol are the most effective alternative to fossil fuel and a critical tool for reducing greenhouse gas emissions and improving air quality,” said Emily Skor, CEO of Growth Energy, a Washington renewable fuels advocacy group.

Jeremy Martin, a senior scientist at the Union of Concerned Scientists, said the greenhouse gas reductions cited in the report could be optimistic.

“Certainly corn ethanol has gotten more efficient, and there are clearly opportunities to get cleaner over time,” said Martin, who adds that the report updates a model the U.S. Environmental Protection Agency used in 2010.

“More recent studies no longer use this approach,” said Martin, who wants Iowa and other states to move beyond corn ethanol production and “accelerate progress on the next generation of cellulosic biofuels,” making ethanol from sources such as corn husks, stalks and other crop residue rather than corn kernels.

Iowa plants in Nevada and Emmetsburg are scaling up cellulosic production. But Martin would like to see ethanol producers use more perennial plants such as switchgrass and miscanthus that are greener and also address water quality and other environmental issues.

Jason Hill, a University of Minnesota associate professor, said the study fails to take into account the “fuel market rebound effect — mainly when you introduce more fuel into the market, prices drop and people tend to consume more.”

“For ethanol to even break even as a climate-reducing strategy, it has to have a carbon footprint that’s at least 50 percent better than gasoline to even break even,” said Hill, who teaches in the bioproducts and biosystems engineering department.

He also criticized the report for failing to address land-use changes in the Midwest and worldwide that resulted from “increased demand for corn production. That carbon has been released to the atmosphere and will continue to be released to the atmosphere as the land is cultivated,” Hill said.

Sabrina Fang, a spokeswoman for the American Petroleum Institute, said the group is reviewing the study but added that part of the ethanol production gains are made through “increased use of natural gas.”

Carl Jardon, an Iowa Corn Growers Association board director, said farmers — and ethanol producers — will only become better at reducing their carbon footprint.

Better seed genetics, for example, mean farmers make fewer trips across their fields.

“We’re getting more yield with fewer inputs all the time,” said Jardon, who farms in Fremont County in southwest Iowa.