When the US Supreme Court last week trashed decades of legal precedent to declare itself the final arbiter of all regulatory questions, many people pointed out that this was the same august body that had displayed confusion about the difference between laughing gas (nitrous oxide) and pollutants (nitrogen oxides). It was a telling, comical example of why the high court’s hubris was such a recipe for disaster.

But a year earlier, the court made another decision about regulation that was just as ludicrous, if not quite as hilarious or highly publicized. Scientists are just now starting to measure the real-world consequences. The troubling early results are a sneak peek of what to expect now that the judicial branch’s so-called Chevron deference to federal regulators is dead, replacing the knowledge of subject-matter experts with that of first-year law clerks.