Cutting greenhouse-gas emissions? It can wait. Photographer: Ty Wright/Bloomberg
Cutting greenhouse-gas emissions? It can wait. Photographer: Ty Wright/Bloomberg

(Revised to correct court reference in fourth paragraph.)

There are all sorts of things people want the federal government to do -- for example, reduce poverty, make highways safer, protect against workplace risks, safeguard privacy online, regulate their least favorite companies or, for that matter, engage in deregulation. Under both Democratic and Republican administrations, federal officials often answer: “Not now.”

In turn, public-interest groups, individuals and businesses have asked federal courts to require public officials to act. And for decades, courts came back with unclear and confusing responses -- until 2007, when the U.S. Supreme Court ruled that the Environmental Protection Agency had acted unlawfully in refusing to regulate greenhouse-gas emissions. That decision led to last week’s proposals for new limits on emissions from existing power plants. And it raised the real possibility that courts would start to oversee federal agencies' authority to set priorities -- and constrain the president’s authority as well.

But in a landmark ruling last month, the nation’s most important lower court, the U.S. Court of Appeals for the District of Columbia, offered more clarity. In general, the court said, federal agencies are entitled to say “not now.”

The case was brought against the EPA by WildEarth Guardians, which wanted the EPA to add coal mines to the list of stationary sources regulated under the Clean Air Act and limit emissions of methane, a potent greenhouse gas. The EPA declined. It did not deny that regulating coal mines might be a good idea. Instead, it said it was focusing on other matters, explaining that it “must prioritize its actions in light of limited resources and ongoing budget uncertainties.” In particular, it noted that, from 2006 to 2013, the budget for the EPA’s Office of Air Quality Planning and Standards had been cut 12 percent (in real dollars), and its staff had been reduced. Under these circumstances, the EPA contended, it was entitled to use its limited “bandwidth” on the most pressing problems.

The court agreed. It said it would not “second-guess EPA’s decision” -- and that, in the absence of unusual circumstances, it would not overturn any federal agency’s choice to not initiate rule making, or to postpone regulatory action for another day, month or year. In so ruling, the court explained that the Supreme Court’s 2007 greenhouse-gas decision should be read narrowly; in that case, the EPA had argued that it lacked the legal authority to regulate carbon dioxide -- a misreading of the Clean Air Act.

To be sure, the appeals court's decision does not give public officials unlimited discretion. If Congress has plainly required them to act, courts will insist that they do so. And when an agency declines to proceed, its explanation has to make sense. If the EPA had denied that coal mines produced methane or said that the whole idea of climate change was a hoax, it would have run into trouble. But the EPA was not refusing to deal with climate change altogether. It was focusing “on more significant sources of air pollutants before addressing coal mines,” which account for only 1 percent of the U.S.'s greenhouse-gas emissions.

Similarly, the EPA may focus on greenhouse gases ahead of other kinds of air pollution, or put water pollution on a back burner. The Occupational Safety and Health Administration may deal with the health risks posed by some workplace chemicals but defer consideration of others. And if the Federal Aviation Administration wants to pursue deregulation, on the theory that air travel is safe and less regulation is in the national interest, it might well be allowed to do exactly that.

In other words, the court’s ruling means that judges will not intervene even if public officials are neglecting significant problems. That’s not necessarily a bad thing. By recognizing that officials, including the president, must set priorities to allocate scarce resources, the court paid respect to the democratic process itself.

To contact the writer of this article: Cass R. Sunstein at csunstei@law.harvard.edu.

To contact the editor responsible for this article: Mary Duenwald at mduenwald@bloomberg.net.