In a 5-4 decision, the court ruled that carbon dioxide is a pollutant under the Clean Air Act and that the U.S. Environmental Protection Agency has the authority to regulate carbon dioxide emissions from automobiles and other vehicles.
"Today’s ruling is a watershed moment in the fight against global warming," said Carl Pope, Sierra Club Executive Director. "The ruling is a total rejection of the Bush administration’s refusal to use its existing authority to meet the challenge posed by global warming. It also sends a clear signal to the markets that the future lies not in the dirty, outdated technologies of yesterday, but in the clean energy solutions that will fuel the economy of tomorrow."
Court Rejects Claim that EPA Lacks Authority to Regulate Vehicle Emissions
During the Bush Administration, the EPA has argued that it has no authority to regulate so-called “tailpipe emissions” of carbon dioxide and other greenhouse gases that contribute to global warming, because they are “non-point” emission sources that are not fixed geographically, unlike coal-fired power plants that are “point” sources and closely regulated. Vehicles account for about 20 percent of U.S. carbon dioxide emissions, while power plants account for about 40 percent.
The Essence of the Case
The case, Massachusetts vs. EPA, put three questions before the court:
- Do states have the right to sue the EPA to challenge its decision?
- Does the Clean Air Act give EPA the authority to regulate tailpipe emissions of greenhouse gases?
- Does EPA have the discretion not to regulate those emissions?
The majority, led by Justice John Paul Stevens, said the EPA had offered a “laundry list” of reasons for failing to regulate carbon dioxide emissions and told the agency that its rationale must be grounded in the Clean Air Act if it wants to continue arguing that it should not be required to regulate carbon dioxide and other greenhouse gases.
"EPA has offered no reasoned explanation for its refusal to decide whether greenhouse gases cause or contribute to climate change," Stevens said in the majority opinion. Joining Stevens in the majority were Justices Stephen Breyer, Ruth Bader Ginsburg, David Souter and Anthony Kennedy, who is often considered the swing vote on the court.
Chief Justice John Roberts and the court’s three other conservative justices—Samuel Alito, Antonin Scalia and Clarence Thomas—dissented and made up the minority in the decision. The four dissenting justices based their dissent on the question of whether the states had the right to sue over this issue.
Congress Must Reinforce the Court Decision with Carbon Caps
While hailing the Supreme Court decision as an important victory in the fight to reduce global warming, leading environmentalists also noted that Congress will now have to take up where the court left off.
“It's important to remember the Court did not rule EPA has to take action on climate change, that’s why this is ultimately up to Congress. The Court did all it can, but if we’re really going to fix climate change, Congress has pass a cap on carbon pollution, and soon," said Fred Krupp, president of Environmental Defense.
"EPA pursued a kitchen sink strategy by throwing a variety of arguments at the Court about why it could simply choose to ignore the law and come up with its own political criteria for deciding what is a pollutant and whether or not to regulate it," said David Bookbinder, director of climate litigation for the Sierra Club. "This ruling simply sets into motion the process to establish the kind of regulations for global warming pollutants that have successfully regulated other pollutants for decades without the kind of dire economic effects predicted by industry."
"It’s unfortunate—but not surprising—that it took a Supreme Court case to clarify the meaning of words such as ‘pollutant,’ ‘endanger,’ ‘weather,’ and ‘climate’ for the Bush administration," Bookbinder said. "The only way EPA can continue to refuse to do its job and not regulate global warming pollutants is by claiming that the effects of global warming pose no danger to the public. Bush’s EPA may try do so, but I suspect they’d be laughed out of court."
To learn how public and political opinions on global warming were changing even before the Supreme Court ruling, see Page 2.
Background on Massachusetts vs. EPA:
- Supreme Court Agrees to Hear Landmark Case on Global Warming
- U.S. Supreme Court Hears Oral Arguments in Global Warming Case
- U.S. Supreme Court Takes First Steps in Landmark Environmental Case
- Supreme Court Rules EPA Can Regulate Greenhouse Gases – Kathy Gill at U.S. Politics: Current Events
- Supreme Court Rules EPA Can Regulate Vehicle Emissions – Robert Longley at U.S. Gov Info/Resources