Skip to content

About PERC

All Areas of Focus

All Research

High Court Cool to Global Warming Claims

The most significant environmental case of the Supreme Court’s just-concluded term was American Electric Power v. Connecticut.  As I explained in an article for PERC Reports, this case arose out of lawsuits filed by several states and environmentalist groups against five large electric power producers, alleging that their emissions of greenhouse gases contributed to the public nuisance of global warming under federal common law.

On June 20, a unanimous Supreme Court held that the plaintiffs’ suits are displaced by the federal Clean Air Act.  Somewhat ironically, this holding was a consequence of the plaintiffs’ prior success bringing global warming claims to court.  In Massachusetts v. EPA, some of the same states successfully argued that greenhouse gases are pollutants subject to regulation under the Clean Air Act.  Yet this conclusion made displacement of the federal common law claims a done deal.  As Justice Ruth Bader Ginsburg’s opinion for the Court made clear, the Court has long held that once Congress delegates regulatory authority to a federal agency, federal common law suits on the same subject matter are displaced.

We hold that the Clean Air Act and the EPA actions it authorizes displace any federal common law right to seek abatement of carbon-dioxide emissions from fossil-fuel fired power plants. Massachusetts [v. EPA] made plain that emissions of carbon dioxide qualify as air pollution subject to regulation under the Act. And we think it equally plain that the Act “speaks directly” to emissions of carbon dioxide from the defendants’ plants.

That the EPA might not regulate as much as plaintiffs would like – and may not regulate enough to mitigate (let alone eliminate) the public nuisance of global warming – is immaterial. In enacting the Clean Air Act, Congress made the scope and stringency of federal greenhouse gas emissions something for the EPA to determine in the first instance, subject to judicial review.

While Justice Ginsburg’s opinion expressly left open the question of whether the Clean Air Act preempts public nuisance claims brought under state law, its displacement discussion explained why courts are particularly ill-suited to addressing climate change claims of this sort.

The appropriate amount of regulation in any particular greenhouse gas-producing sector cannot be prescribed in a vacuum: as with other questions of national or international policy, informed assessment of competing interests is required. Along with the environmental benefit potentially achievable, our Nation’s energy needs and the possibility of economic disruption must weigh in the balance. The Clean Air Act entrusts such complex balancing to EPA in the first instance, in combination with state regulators. . . .

It is altogether fitting that Congress designated an expert agency, here, EPA, as best suited to serve as primary regulator of greenhouse gas emissions. The expert agency is surely better equipped to do the job than individual district judges issuing ad hoc, case-by-case injunctions. Federal judges lack the scientific, economic, and technological resources an agency can utilize in coping with issues of this order. . . . Judges may not commission scientific studies or convene groups of experts for advice, or issue rules under notice-and-comment procedures inviting input by any interested person, or seek the counsel of regulators in the States where the defendants are located. Rather, judges are confined by a record comprising the evidence the parties present. Moreover, federal district judges, sitting as sole adjudicators, lack authority to render precedential decisions binding other judges, even members of the same court.

While the Court’s holding only reached plaintiffs’ federal common law claims, this discussion may give federal courts pause before approving the plaintiffs’ state-law-based claims. Grounding judicial management of climate policy in state common law does not make it any easier. If anything it would be more difficult insofar as different state-law rules could produce different outcomes. Whatever the merits of common law nuisance suits in other pollution contexts, American Electric Power v. Connecticut means federal courts will not be eager to hear such claims when based on global warming.

Related Content