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U.S. Supreme Court Decides Massachusetts v. EPA

(Updated 4/11/07)

On April 2, 2007, the United States Supreme Court issued its 5-4 decision in Massachusetts v. U.S. Environmental Protection Agency, which concerned whether EPA has authority under the Clean Air Act to regulate greenhouse gas emissions from motor vehicles.  This is the first time that the Supreme Court has looked at the issue of global climate change.

This analysis begins with the background of the case, and then summarizes the majority and dissenting opinions.  It then discusses the direct effects of the decision on motor vehicle regulation; the indirect effects on stationary source regulation; the implications for Congressional action; and the effects on other pending and contemplated litigation.


In 1998 and 1999, two successive EPA general counsel issued legal opinions that EPA had the authority under the Clean Air Act to regulate carbon dioxide emissions.  In 1999, a group of 19 private organizations filed a rulemaking petition with EPA to regulate greenhouse gas emissions from new motor vehicles under the Clean Air Act.  EPA requested public comments on the petition, and received more than 50,000 comments.  EPA also commissioned a report from the National Research Council, which concluded that greenhouse gases are accumulating in the atmosphere as a result of human activities, and are causing temperatures to rise.

EPA did not rule on the petition before President Clinton left office.  The new EPA general counsel under President Bush issued an opinion disagreeing with his predecessors about EPA’s authority.  On September 8, 2003, EPA denied the rulemaking petition, finding that the Clean Air Act does not authorize EPA to issue mandatory regulations to address global climate change, and that even if EPA had the authority, it would be unwise to do so at this time.  EPA found that extensive Congressional attention to climate change, without the enactment of a specific regulatory scheme, meant Congress did not intend for one to be adopted.  Moreover, EPA found that there was still scientific uncertainty over whether human activities were really leading to global warming.

The petitioners, joined by several states and local governments, asked the U.S. Court of Appeals for the D.C. Circuit to overturn the order.  The three judges on the D.C. Circuit panel each issued different opinions, but two of them found that EPA properly denied the petition. 415 F.3d 50 (D.C. Cir. 2005).

The Supreme Court granted certiorari and heard argument on November 29, 2006.  Much of the argument was devoted to the question of whether the plaintiffs had standing to sue.  Most observers of the argument came away convinced that a 5-4 decision would result, with the only question being which way Justice Kennedy would vote.  They were correct.

Majority Opinion

Justice Stevens delivered the opinion of the Court, joined by Justices Kennedy, Souter, Ginsburg and Breyer.   Citing the National Research Council report and the declarations of several scientists, the Court found that “[t]he harms associated with climate change are serious and well recognized,” and that “EPA does not dispute the existence of a causal connection between man-made greenhouse gas emissions and global warming.”  Addressing the plaintiffs’ standing, the Court declared that “[o]nly one of the petitioners needs to have standing to permit us to consider the petition for review,” and that a sovereign state, Massachusetts, was among the plaintiffs.  Petitioners’ uncontested affidavits showed that “the rise in sea levels associated with global warming has already harmed and will continue to harm Massachusetts.  The risk of catastrophic harm, though remote, is nevertheless real.”  Though an EPA decision to regulate greenhouse gas emissions from new motor vehicles might have only a small benefit to the Massachusetts coastline, that is enough to confer standing.  The Court found that EPA’s argument against standing “rests on the erroneous assumption that a small incremental step, because it is incremental, can never be attacked in a federal judicial forum.”

With standing established, the Court turned to the merits.  The Court said it had “little trouble concluding” that the Clean Air Act authorizes EPA to regulate greenhouse gas emissions from new motor vehicles in the event that it forms a judgment that such emissions contribute to climate change.  The Clean Air Act has a “sweeping definition” of “air pollutant” that “embraces all airborne compounds of whatever stripe.”

According to the Court, “Rather than relying on statutory text, EPA invokes postenactment congressional actions and deliberations it views as tantamount to a congressional command to refrain from regulating greenhouse gas emissions.”  The Court also rejected EPA’s conclusion that even if it does have statutory authority to regulate greenhouse gases, it would be unwise to do so, finding that this “rests on reasoning divorced from the statutory text.”

The Court found that “[u]nder the clear terms of the Clean Air Act, EPA can avoid taking further action only if it determines that greenhouse gases do not contribute to climate change or if it provides some reasonable explanation as to why it cannot or will not exercise its discretion to determine whether they do.”  It declared that “EPA has offered no reasoned explanation for its refusal to decide whether greenhouse gases cause or contribute to climate change,” and therefore its action was “arbitrary, capricious, … or otherwise not in accordance with law.”  The Court explicitly did not reach the question of whether on remand EPA must make an endangerment finding, or whether policy concerns can inform EPA’s actions in the event that it makes such a finding.

Dissenting Opinions

Two dissenting opinions were filed – one by Chief Justice Roberts on standing, and one by Justice Scalia on the merits.  Both dissenting opinions were joined by all four dissenting members (Chief Justice Roberts and Justices Scalia, Thomas and Alito).

Chief Justice Roberts expressed alarm that the majority opinion was opening up standing too broadly.  He said there was no basis for giving special solicitude to states as plaintiffs.  He declared that there was no evidence that Massachusetts was really losing coastal land as a result of climate change, or that such loss was caused by EPA’s failure to regulate greenhouse gases from motor vehicles, or that any injury they suffer would be redressed by a victory in this case.

Justice Scalia found no requirement in the Clean Air Act that the Administrator of EPA make a judgment about whether to regulate greenhouse gases, as opposed to deferring any decision.  He also found that EPA had looked at the science and reasonably concluded that there is too much scientific uncertainty to regulate greenhouse gases.   Moreover, he disagreed with the majority’s reading of the term “air pollutant” in the Clean Air Act, and said that EPA’s judgment that greenhouse gases do not qualify should receive deference.

Next Steps

The Supreme Court remanded the matter to EPA to make an “endangerment finding” with respect to greenhouse gases.  If EPA finds no endangerment, litigation is certain. If it does find endangerment, EPA must then decide what to do.  Normally, an endangerment finding for an air pollutant is followed by the promulgation of a national ambient air quality standard (NAAQS) for that pollutant, keyed to the concentration level below which there is no expected adverse impact on public health or welfare.  It is not clear how that would work here, because the danger from greenhouse gases derives not from breathing them (the sort of impact that can be gauged in toxicological or epidemiological studies) but rather from their cumulative global impact.

The day after the Supreme Court decision, President Bush was asked about it at a Rose Garden news conference.  He said, “I have said that it is a serious problem, I recognize that man is contributing greenhouse gases.”  He added, “It’s going to require new technologies, which tend to be expensive, and it’s easier to afford expensive technologies if you’re prosperous.”  He also said, “Unless there is an accord with China, China will produce greenhouse gases that will offset anything we do in a brief period of time.”

The Supreme Court did not set a timetable for EPA action, and there are no deadlines in the text of the Clean Air Act.  It ordinarily takes several years for EPA to promulgate a NAAQS.  Thus there is a good chance that EPA will take no definitive action before President Bush leaves office in January 2009.

Sen. Barbara Boxer (D-CA), chair of the Senate Committee on Environment and Public Works, said she would summon EPA officials before her committee this month to explain how they would follow the Supreme Court ruling.  Rep. John Dingell (D-MI), chair of the House Energy and Commerce Committee, released a statement saying, “While I still believe Congress did not intend for the Clean Air Act to regulate greenhouse gases, the Supreme Court has made its decision and the matter is now settled. Today’s ruling provides another compelling reason why Congress must enact, and the President must sign, comprehensive climate change legislation.”  Thus intense Congressional activity will continue, but there is no clear veto-proof majority.

Effect on Stationary Sources

The ruling directly applies only to new motor vehicles.  The Clean Air Act regulates stationary sources of air pollution (such as power plants and factories) differently than it does mobile sources such as vehicles.  However, a case pending in the D.C. Circuit, Coke Oven Environmental Task Force v. EPA, concerns whether the Clean Air Act gives EPA authority to regulate greenhouse gases from stationary sources.  That case was stayed pending the outcome of Massachusetts v. EPA.  The Coke Oven case will now proceed.  The Supreme Court has settled the issue of the plaintiffs’ standing (ten states are among the plaintiffs in Coke Oven), but other issues are open.

Effect on Pending Motor Vehicle Litigation

Under the Clean Air Act and the Energy Policy and Conservation Act (EPCA), regulation of tailpipe emissions and fuel economy from new motor vehicles is vested in the federal government, except that California may adopt its own rules if EPA grants a waiver, and other states may adopt the California rules.  In 2004 the California legislature adopted a law, called the Pavley Amendment, that mandated rules limiting greenhouse gas emissions from new motor vehicles sold in California beginning in the 2009 model year, and in 2004 the California Air Resources Board adopted implementing regulations. The automobile industry challenged these rules in a case called Central Valley Chrysler-Jeep Inc. v. Witherspoon, currently pending in the U.S. District Court for the Northern District of California.  EPA had refused to consider California’s request for a waiver, but immediately after the Supreme Court ruled, EPA announced that it would issue a notice for a 60-day public comment period about a potential waiver.  The public hearing will likely take place this summer.

Both the plaintiffs and defendants in the California case are claiming that the Massachusetts decision helps them.  The district court will likely consider these arguments shortly.

Thirteen other states adopted California’s standards, and lawsuits have been filed in several of those as well.  The suit that is furthest along is in Vermont, styled as Green Mountain Chrysler Plymouth Dodge Jeep v. Crombie.   As this analysis is being written, that case is going to trial in the U.S. District Court in Vermont.  Two days after the Massachusetts ruling, lawyers for the state asked the trial judge to dismiss the case on the grounds that the Supreme Court had settled the matter.  The automobile industry’s counsel countered that the Supreme Court had not resolved the central question of whether Vermont’s regulations amount to fuel economy standards rather than emissions limitations, and are therefore preempted by EPCA.  The court refused to dismiss the case and said it would proceed toward trial.  A week earlier, the court had rejected a motion by the automobile industry to close the trial to the press because trade secrets would be divulged.

Effect on Pending Public Nuisance Cases

There are at least three pending suits that claim that greenhouse gases are a public nuisance: 

  1. Connecticut v. American Electric Power is a suit by eight states and New York City against five large electric utilities.  The U.S. District Court for the Southern District of New York dismissed the case on the grounds that it presented political questions that should not be resolved by the courts.  406 F. Supp.2d 265 (S.D.N.Y. 2005).  The plaintiffs’ appeal was argued before the U.S. Court of Appeals for the Second Circuit in June 2006. 
  2. Comer v. Murphy Oil USA, Inc. is a suit brought by several property owners in Mississippi against a broad range of industrial interests claiming that greenhouse gas emissions worsened the effects of Hurricane Katrina.  The U.S. District Court for the Southern District of Mississippi is considering motions to dismiss. 
  3. People of the State of California ex rel. Lockyer v. General Motors Corp. is a suit by the California Attorney General against several automakers.  The U.S. District Court for the Northern District of California heard oral arguments on March 6, 2007.

The day after the Massachusetts ruling, attorneys for the automakers asked the court to dismiss on the grounds that the Supreme Court decision grants authority to regulate automobile emissions to the federal government, not the states.  The new Attorney General of California, Jerry Brown, countered that the decision helps California because the Supreme Court strengthened the authority of states to protect their citizens from climate change.  It is understood that counsel for both sides in the Connecticut case are making submissions to the Second Circuit.


(Updated 7/30/07)

The U.S. District Court for the Eastern District of California has ruled that the U.S. Fish and Wildlife Service (FWS) should have considered the effect of climate change in issuing a biological opinion under the Endangered Species Act.

The decision concerned the Long-Term Central Valley Project and State Water Project Operations Criteria and Plan, which govern large water diversion projects involving the California Bay (Sacramento-San Joaquin) Delta.  The Delta is inhabited by a fish called the Delta smelt, whose population has declined significantly.  The FWS issued a biological opinion about the project's effect on, among other species, the Delta smelt.  The biological opinion assumed that the hydrology of the water bodies affected by the project will follow historical patterns for the next 20 years.  However, during the administrative proceedings, evidence was introduced that climate change will significantly change the hydrology.  The evidence suggested that climate change will produce earlier flows, more floods, and drier summers. The court found that it was arbitrary and capricious for the FWS to ignore this evidence.  This was one of the several deficiences found by the court in the biological opinion.  The court called for the scheduling of a separate remedies hearing.

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