Supreme Court to Weigh in on Greenhouse Gas Common Law Nuisance Cases

The Supreme Court announced on December 6 that it would hear an appeal in one of the several common law nuisance cases against greenhouse gas (GHG) emitters that are making their way through the courts. By granting ceritiorari in AEP v. Connecticut, the Supreme Court has signaled its intention to weigh in on the appropriate role of the courts in addressing damages caused by climate change. As explained below, possible future regulatory actions by EPA or, alternatively, action by Congress to restrict EPA’s regulatory authority, could be factors that influence the Court’s decision.

The AEP v Connecticut case involves a suit brought by a number of states and land trusts against the six largest utility emitters of GHGs. The case has traveled a somewhat circuitous route to the highest court. In 2005, the District Court dismissed the case on the grounds that it presented a political question that was best left to the legislature or executive.  In 2009, the Second Circuit court reversed that decision and ruled that the plaintiffs had standing to bring the case (e.g., involves a case or controversy that can be resolved by legal action), traditional common law was applicable in these circumstances (e.g., that such claims could be addressed by the courts), and existing federal regulation had not sufficiently occupied the space as to displace any need for the application of common law. The Supreme Court agreed to hear the appeal of this decision. The steps to date all involve questions of law and must be sorted out simply to determine whether or not an actual trial on the facts will ever take place.

The Supreme Court may well decide the case on issues related to standing or whether the case presents a non-judiciable political question. Leaving these two issues to others to debate, the third potential basis for a decision – whether EPA regulatory actions have displaced common law – raises important implications that relate to what Congress and EPA may or may not do in the next few months. 

The Second Circuit opinion looked in detail at the claim by the defendants that existing law (including the Clean Air Act) had effectively occupied the field and thus displaced federal common law. It held that since no comprehensive regulatory regime existed that displacement had not occurred. The Solicitor General’s office weighed in on this issue in support of displacement. In their brief to the Supreme Court, they argued that in the time since the Second Circuit’s decision, EPA had completed its endangerment finding and issued rules to control GHGs from major new or modified sources.

Whether or not the Clean Air Act effectively displaces federal common law may well be decided by the Supreme Court based on future actions by EPA and Congress. To the extent that EPA moves forward to regulate stationary sources, including controls specifically on utilities, the Court may be more inclined to find a basis that displacement has occurred and not allow the case to move forward. To the extent that Congress steps in and takes away EPA’s authority under the Clean Air Act to regulate GHG emissions from stationary sources or substantially delays its use of this authority, the courts may have a harder time finding that displacement has occurred. With the Supreme Court expected to hear the case sometime this spring and decide by early summer, the impact on the Supreme Court’s deliberations is just one more thing to consider as EPA and Congress consider their next steps.    

Steve Seidel is Vice President for Policy Analysis