Supreme Court’s EPA ruling can’t stop coal’s long slide

The following editorial appears on Bloomberg View:

It took 41 years from the time it was enacted by Congress for the Clean Air Act to limit the amount of mercury and other poisonous substances that coal-fired power plants are allowed spew into the air. A ruling Monday from the Supreme Court, which struck those limits on something very close to a technicality, means that some parts of the country will have to wait longer. But make no mistake: Coal’s slide into obsolescence will not be stopped.

At issue in the court’s decision was the point at which the Environmental Protection Agency needed to consider the cost of its mercury restrictions. The agency operated under the assumption that cost needed to be calculated only when it came time to set the limits. The Supreme Court disagreed, ruling that the EPA should have considered costs even in the process of deciding that mercury needed regulating.

A lower court will now determine whether to throw out the rule altogether or tell the EPA what to do to fix it. You don’t need to be an environmentalist to be concerned. The mercury that coal plants send skyward rains down into lakes and rivers, where it’s ingested by fish; when pregnant women eat the fish, their children can suffer reduced intelligence and are left at greater risk of behavioral disorders.

By blocking not just mercury but also arsenic, cyanide, acid gas and other pollutants, the EPA’s rules aimed to prevent 11,000 premature deaths and 4,700 heart attacks a year, as well as significantly reduce rates of childhood asthma and acute bronchitis.

The EPA’s rule took effect in April, which means most plants have already installed the equipment needed to scrub mercury and other toxic emissions. But some have asked for extra time, and if the rule is voided altogether, they'll be able to keep emitting at their current levels. Even plants that haven’t delayed could theoretically return to poisoning the air; after all, the pollution-control equipment is expensive to operate.

But that doesn’t have to happen. The District of Columbia Circuit Court, which will probably hear the case again later this year, could leave the regulation in place while the EPA goes back through the rule-making process to meet the circuit court’s requirements. The agency won’t say whether it has already started preparing a revised finding, should one become necessary; if not, it should begin now.

The worst-case scenario is that the court makes the EPA go through the whole rule-making process again, start to finish; the agency isn’t able to do that before January 2017; and a new president takes office who is less committed than Barack Obama to clean air and children’s health.

Even then, coal-fired power plants in the U.S. will remain on their downward trajectory. The combination of other environmental regulation, cheap natural gas and growing public concern over climate change is shrinking America’s fleet of coal plants. The EPA has only to make sure this ruling doesn’t slow that process any more than it must.