EPA need not regulate carbon dioxide emissions, but must ensure actions comply with Clean Air Act

September 3, 2007 | Roger McEowen


In a recent opinion, a majority of the U.S. Supreme Court ruled that the EPA had offered “no reasoned explanation” for its refusal to regulate carbon dioxide and other emissions from new cars and trucks that contribute to climate change.  The Clean Air Act (CAA), EPA argued, did not give the agency the authority to address “global climate change” and that, in any event, executive policy specifically addressing “global warming” warranted the EPA’s refusal to regulate in such area.  However, the Court held that the plaintiffs had standing to challenge the EPA’s denial of the plaintiffs’ rulemaking petition, and EPA had the statutory authority to regulate emissions from new automobiles and that their decision to not regulate such emissions was arbitrary and capricious.  The majority opinion does not require EPA to change its position, however.  EPA is only required to demonstrate that whatever it chooses to do complies with CAA requirements.  The Court stated that EPA must “ground its reasons for action or inaction in the statute.”

The dissenting Justices (including the Chief Justice) opined that the plaintiffs’ lacked standing, that their claims were non-justiciable and that the majority had impermissibly relaxed the standing requirements of Article III of the Constitution.  According to the dissent, Supreme Court precedent placed the burden on the plaintiffs to allege an injury that is fairly traceable to the EPA’s failure to promulgate new motor vehicle greenhouse gas emission standards, and that such injury is likely to be addressed by the prospective issuance of such standards. 

Note:  The regulation of carbon dioxide emissions could have important  implications for the ethanol industry.  Scientific studies have shown that the use of ethanol-blended fuels leads to increased levels of aldehydes and peroxyacyl nitrates which are presently unregulated under the CAA.  Other studies have shown that while ethanol-blended fuel (specifically E-85) reduces the atmospheric levels of two carcinogens, benzene and butadiene, it increases formaldehyde and acetaldehyde, and significantly increases ozone, a prime ingredient of smog.  Massachusetts, et al. v. Environmental Protection Agency, et al., 127 S. Ct. 1438 (2007).