On Monday, for the third time in seven years, the Supreme Court will consider the scope of the federal government’s power to regulate the emission of greenhouse gases, which are a major contributor to global climate change.
In two earlier cases, the court held that under the Clean Air Act, the Environmental Protection Agency could regulate such emissions, from both motor vehicles and stationary sources like power plants. Of course, the Clean Air Act was passed in 1970, well before scientists understood the threat of climate change, and so didn’t take greenhouse gases into account. But if the law is to remain effective, the court rightly reasoned in 2007, the E.P.A. must have the authority and “regulatory flexibility” to respond to “changing circumstances and scientific developments.”
This flexibility is what the agency exercised in 2011 when it issued tailpipe-emission standards for new cars as a way of reducing greenhouse gas emissions. By imposing those new standards on vehicles, or “mobile sources,” the agency said, it then had to regulate greenhouse gas emissions from major stationary sources, too.
Under the law, a major source is one that annually emits 100 or 250 tons of conventional air pollutants, like lead. But carbon dioxide, the most common greenhouse gas, is emitted in much larger amounts, which would force the regulation of tens of thousands, and possibly millions, of sources, from hospitals to small local businesses, at an estimated cost of $21 billion per year. The E.P.A. determined that the Clean Air Act never intended such an outcome, so it set a temporary threshold of 100,000 tons to capture just the biggest emitters of greenhouse gases.
In 2012, the United States Court of Appeals for the District of Columbia Circuit upheld that decision, reasoning that the Supreme Court had previously ruled that the E.P.A. could regulate greenhouse gases as a harmful air pollutant. And under the plain language of the law, the court said, the agency must require permits for the emission of “any air pollutant” that harms public health or welfare. Yet industry representatives continued to argue that the E.P.A. had overstepped its bounds. The Supreme Court agreed to decide only one issue: whether the new vehicle emissions standards did, in fact, “trigger” the regulation of power plants, industrial operations and other stationary sources of emissions.
The complex layers of regulatory interpretation should not obscure the larger issue at stake. As with most battles over environmental regulation, the struggle is between the bottom-line economic concerns of business and the government’s reasonable efforts to protect human health and the environment. Virtually everyone accepts the overwhelming evidence of human influence on climate change and the urgent need to address it, except for a handful of hardened skeptics and those who benefit financially from less regulation. The question is who gets to decide the best way to go about reducing harmful emissions.
The optimal solution would be for Congress to update the Clean Air Act, but that isn’t going to happen anytime soon. In the meantime, the E.P.A. is well within its authority to interpret the law as broadly as it has. It was written that way four decades ago, and the Supreme Court has repeatedly and properly construed the agency’s powers broadly. This time is no different.