The U.S. Environmental Protection Agency scored another win in the ferocious battle over the regulation of greenhouse gases when the U.S. Court of Appeals for the D.C. Circuit on December 20 declined to review its June decision upholding the agency’s interpretation of the Clean Air Act.

In a 6 to 2 vote, the court denied petitions by the U.S. Chamber of Commerce, the National Association of Manufacturers and others to rehear the case en banc, but in a rare step, two judges issued lengthy dissents and three penned a defense of their original opinion.

The one thing they all agreed on: the case is of “exceptional importance,” as Chief Judge David Sentelle and judges David Tatel and Judith Rogers noted in the 52-page order

Sentelle, Tatel and Rogers wrote the original June 26 opinion in Coalition for Responsible Regulation Inc. v. EPA, where they found that the agency’s interpretation of the Clean Air Act was “unambiguously correct” and upheld EPA rules limiting emissions of six greenhouse gases.

“To be sure, the stakes here are high,” the trio wrote in the order issued today. “The legal issues presented, however, are straightforward, requiring no more than the application of clear statutes and binding Supreme Court precedent. There is no cause for en banc review.”

Judges Janice Rogers Brown and Brett Kavanaugh, however, sharply disagreed.

Brown began her dissent with a flight of poetic fancy, describing a summer in Los Angeles, where “magenta blossoms of Bougainvillea fall like lavish draperies from redwood garden trellises.” One night, after listening to “the agitated thrashings of the jacaranda trees in a fitful wind,” she awoke and for the first time saw the surrounding mountains, previously obscured by smog.

Her point: the Clean Air Act was intended to address the “choking, stifling, and degenerative effect of airborne pollutants on human beings,” not nebulous future harm from greenhouse gases.

“Any harm to human health and welfare flowing from climate change comes at the end of a long speculative chain,” Brown wrote. “If there can be this much logical daylight between the pollutant and the anticipated harm, there is nothing the EPA is not authorized to do….the right endangerment finding would allow EPA to rule the world.”

The problem with her argument, as Brown herself acknowledged, is that “The Supreme Court has declared that [greenhouse gases] like CO2 are pollutants within the meaning of the Act.”

Still, she added, “I do not choose to go quietly,” and argued that the high court’s 2007 decision in Massachusetts v. EPA “does not compel this outcome.”

Sentelle, Rogers and Tatel disagreed, writing that “the Court expressly rejected many of the arguments her dissent now presses.”

Both Brown and Kavanaugh took particular issue with the EPA’s so-called “tailoring” rule. The Clean Air Act specifies that entities that emit 100 to 250 tons of pollutants per year need permits. If that standard was applied to greenhouse gases, it would mean about six million entities would need permits. EPA said this was an absurd result, and so it “tailored” the rule by raising the permitting thresholds for greenhouse gases.

Kavanaugh argued the EPA should have adopted a narrower interpretation of the term “air pollutant” to avoid this result. “When an agency is faced with two initially plausible readings of a statutory term, but it turns out that one reading would cause absurd results, I am aware of no precedent that suggests the agency can still choose the absurd reading and then start rewriting other perfectly clear portions of the statute to try to make it all work out,” he wrote.

“Allowing agencies to exercise that kind of statutory re-writing authority could significantly enhance the Executive Branch’s power at the expense of Congress’s and thereby alter the relative balance of powers in the administrative process,” Kavanaugh continued. “I would not go down that road.”

Jenna Greene is a reporter for The National Law Journal, a Legal affiliate based in New York.