Arguments and judicial reasoning in administrative law cases usually focus on the case at hand. Indeed, the Administrative Procedure Act (APA) commands that narrow focus. The APA does not give the courts any role in shaping the laws governing administrative agencies, for that is what Congress does. Instead, it gives the courts a modest, albeit difficult responsibility: They may determine whether a particular agency action is arbitrary and capricious or contrary to law. Therefore, parties challenging an agency rule they disapprove of generally argue that the agency has violated some restraint stated in the statute or exercised its discretion in an arbitrary way.

But in the U.S. Supreme Court case heard last week about the scope of EPA's authority to regulate greenhouse gas emissions (West Virginia v. EPA), coal companies relied heavily on a "parade of horribles" argument — a listing of bad things that …

This op-ed was originally published by Slate.

Last fall, on the same day that the parties to the Paris Agreement gathered in Glasgow for their first day of their annual international climate meeting, the U.S. Supreme Court announced it would review an appellate court decision about the U.S. Environmental Protection Agency's authority to regulate greenhouse gases from fossil fuel power plants under the Clean Air Act.

Fast forward half a year: On February 28, the day that the U.N. Intergovernmental Panel Climate Change issued its sobering report on climate adaptation and harms to human and planetary well-being, the court heard oral arguments in the case—West Virginia v. EPA.

Once again, it was a split-screen reality.

In reaction to the report, U.N. Secretary-General António Guterres stated, "Today's IPCC report is an atlas of human suffering and a damning indictment of failed climate leadership …

The National Labor Relations Act (NLRA) leaves no doubt about its purpose. Enacted in 1935, it was set against a backdrop of decades of intense and often violent labor strife. Recall the massacre of striking coal miners at Ludlow, Colorado (1914); the bloody Battle of Blair Mountain in West Virginia (1921), which pit miners against the militia; and the West Coast Longshoremen’s Strike (1934) over union representation, which revealed organized workers’ enormous power over the nation’s economy.

The NLRA was designed to minimize strife by requiring employers to recognize employees’ efforts to engage in “mutual aid and protection”; adjudicating conflict so as to avoid direct action; and, to quote from the act itself, by “encouraging practices fundamental to the friendly adjustment of industrial disputes … and by restoring equality of bargaining power between employers and employees.”

Employers, naturally, prefer to deal with their workers one on …

Imagine you're in the market for a new furnace. You decide to buy a more fuel-efficient system — even though the price tag is higher — because it will lower your monthly heating bills. Another selling point: The fuel-efficient furnace emits less carbon into the atmosphere — a benefit you can't quite quantify but that you value nonetheless for its small salubrious effect on the planet.

Policymakers go through a similar — though much more complex — process when implementing laws. But an obscure federal mandate known as cost-benefit analysis renders them unable to fully account for costs and benefits that are difficult to measure in dollars and cents, like the large-scale value to society of federal rules that protect public and environmental health.

Despite its name, a true analysis of a rule's full benefits is impossible.

I mean, really: How can public officials put a price on a stable climate or …