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Nationwide report on removing, reducing CO2 in US includes O’Neill School research

Dec 11, 2023

Jerome Dumortier has been studying carbon management, agricultural emissions and bioenergy since he began working on his Ph.D. in economics. Now, the associate professor at the Indiana University O’Neill School of Public and Environmental Affairs in Indianapolis and his research are part of a large-scale nationwide report highlighting opportunities to remove large amounts of carbon dioxide in the United States.

Jerome Dumortier. Photo courtesy of the O'Neill School Jerome Dumortier. Photo courtesy of the O'Neill School

“This is the culmination of the last 15 years of my research,” he said.

Researchers from all 50 states contributed to the “Roads to Removal” report from the Lawrence Livermore National Laboratory, providing a pathway for the United States to remove carbon dioxide from the atmosphere as part of a broader plan to become a net-zero-greenhouse-gas nation by 2050.

“There has always been a patchwork of people working on these topics,” Dumortier said. “Having all those people and their work together in one report is very exciting to me.”

In the report, Dumortier and his co-authors collectively outline different ways in which each region and state can address carbon dioxide levels in the United States.

Including forestry management in the Southeast, wind energy in the West, underground carbon storage across the country and agricultural management in the Midwest, the report examines land-based methods to remove what authors predict to be at least 1 gigaton — that’s 1 billion tons — of carbon dioxide equivalents per year.

Dumortier’s area of expertise focuses on agriculture, bioenergy production and electric vehicles.

“We now have more electric vehicles in the United States, which reduces the demand for ethanol, thus reducing the demand for corn,” he said. “A lower demand for corn means there’s some land planting reallocation that could happen because corn isn’t as profitable anymore.”

Dumortier said that means farmers could shift to a new type of crop: switchgrass. He said it’s a more efficient crop than corn in terms of energy content per acre and could be used to generate the electricity needed to power the growing electric vehicle fleet.

“Switchgrass absorbs more carbon in the soil,” he said. “When switchgrass is harvested and processed, it also creates more energy than corn does. You get more energy per acre of switchgrass than you do per acre of corn.”

Switchgrass is also a perennial, so farmers wouldn’t have to replant every year. It can survive for 10 years.

But Dumortier admits there are barriers to making the switch to switchgrass.

“There’s a lot of hesitation because it has not traditionally been done,” he said. “Plus, farmers are in a profit-maximizing enterprise. Right now, switchgrass comes with very high production costs, lower yields for the first couple of years, and there is really no market for it. That’s why we need to create a market and financial incentives to make it a viable option for farmers.”

That is where policy-makers come in, according to Dumortier. Without effective policies and financial benefits, farmers won’t change their crops. He said current mandates to produce cellulosic ethanol from sources like switchgrass are not being enforced, and the necessary infrastructure — such as bioenergy plants — to turn the crop into energy hasn’t been supported. At least not yet.

“There has to be a government policy there to make it happen,” he said. “Without some sort of support, the shift is unlikely to occur naturally.”

But growing and harvesting switchgrass is just one way Indiana can help reduce and remove CO2. Another is reviewing and adjusting crop management practices around the state — “for example, using cover crops that increase the soil carbon levels and managing field tillage to reduce the carbon that tilling releases from the soil,” Dumortier said.

He said Hoosier farmers also could collect agricultural residue — the stalks, leaves and cobs — left behind after a harvest. But, much like converting to switchgrass, he said there is also controversy about the impact of that practice.

“Agricultural residues return important and necessary nutrients into the soil,” he said. “There’s the concern that harvesting it may reduce the nutrient value of the soil, which can have big implications on future crops. That’s why there’s a lot of discussion about exactly how much of those leftovers you can actually harvest to convert into biofuels without hurting the soil.”

Authors hope the “Roads to Removal” report sets the stage for leaders in every corner of the nation to have those discussions about the options presented. The “Roads to Removal” website includes the entire report as well as state-by-state fact sheets.

Author

O’Neill School of Public and Environmental Affairs

Leslie Wells

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