WASHINGTON (CN) — A D.C. Circuit panel on Friday expressed skepticism about a federal renewable-biofuel program, raising concerns over land usage and resulting impacts on the environment, wildlife and climate during nearly three hours of arguments.
Congress created the program in 2007 via the Energy Independence and Security Act. With the goal of reducing vehicle emissions, it directed the Environmental Protection Agency to set annual renewable fuel standards mandating the mix of certain biofuels into vehicle fuel.
In 2022, lawmakers asked the EPA to set new standards for volumes of corn and soy — the primary ingredients in ethanol and biodiesel — and review their environmental impacts, including on air quality, climate change, ecosystems and water quality.
Enter the Center for Biological Diversity and the National Wildlife Federation, two environmental groups that have challenged the EPA’s new rules for 2023-2025. Those rules would continue to increase production of biofuels, from 0.84 billion gallons in 2023 to 1.38 billion by 2025.
Because of this increase, the groups challenged the government’s determination that the new volume was unlikely to adversely affect the environment. They've urged the panel to vacate the EPA’s rule, forcing the agency to make a new determination on corn and soy volumes.
Representing the Center for Biological Diversity, attorney Margaret Coulter argued the EPA had failed to fully consider potential impacts like water pollution, habitat destruction or hypoxia — that is, lower or depleted oxygen.
Coulter pointed to the EPA’s own research, which found that the rule would cause the destruction of 1.3 million acres along the whooping crane’s migratory corridor, as well as nearly 5% of the Salt Creek tiger beetle’s critical habitat. Despite these outcomes, the EPA concluded the rule would “not injure a single individual of any listed species.”
Calling that conclusion “implausible,” Coulter pointed to the Chesapeake Atlantic sturgeon’s habitat range, which also includes nearby land where wetland conversion, pollution and other human activity could impact waterways. Of it, around 1.2 million acres is engaged in soy production, while another 1 million in involved corn production.
Under the EPA’s new rule, Coulter said, an additional 14,131 acres would be converted to soy production and another 1,170 acres to corn. Ultimately, the additions would impact 4,238 acres of critical habitat for the endangered species.
While those figures appear small compared to the species’ total 10-million-acre range, the harm was enough to violate the Endangered Species Act’s standard for determining a significant impact, Coulter said.

The three-judge panel, made up of U.S. Circuit judges Cornelia Pillard, Michelle Childs and Gregory Katsas — two Barack Obama appointees and a Donald Trump appointee, respectively — seemed receptive to Coulter’s argument.
Justice Department attorney Alexander Purpuro, who represented the EPA in defending the new rule, asserting that the rule’s impact on water pollution would be marginal and outweighed by future benefits.
Pupuro said that the agency’s analysis showed that in one example, at the mouth of the Mississippi, the rule would lead to a mere 1% estimated increase in pollution and would have no detectable impact on any species there.
Still, the judges were skeptical. “I’m having a hard time seeing that as not just sweeping under the rug,” Pillard said.
Purpuro pushed back. The National Marine Fisheries Service determined that any potential downstream effects would be diluted as that pollution made its way to larger bodies of water, he argued.
Carrie Apfel, deputy managing attorney at Earthjustice, represented the National Wildlife Federation on Friday. She argued that the EPA’s environmental analysis was flawed in several ways.
The core issue, she said, was a failure to consider the opportunity cost of using farmland to grow corn and soy rather than putting it to alternative uses that could better combat climate change.
“This cost recognizes that land is a finite resource," Apfel said. "If you’re keeping land in production for corn and soy for biofuels, that particular land can’t be used for other resources, such as growing food for human consumption or animal feed or sequestering and storing carbon."
Using the land for biofuel production leads to land-clearing elsewhere for food production, she added — a further environmental impact that she said the government had ignored.
In his arguments, Purpuro said that the EPA had conducted an adequate opportunity cost analysis and found that the new rule would create economic benefits, such as job creation and lowered greenhouse gas emissions when compared to petroleum fuel production.
Pillard pressed Apfel and asked what else the EPA could have done in its analysis. The judge highlighted the agency’s review of scientific studies on the emissions from corn ethanol and soy diesel, which she said showed biofuels ultimately produce less emissions than petroleum.
But Apfel argue the EPA should have independently analyzed the underlying data from those studies, rather than accept them at face value.
“It wold be like this court looking at a range of GPAs for law clerk applicants without looking at the underlying data, like where they went to school, what their grades were and what classes they took,” she said.
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