Attempts by the Environmental Protection Agency to regulate greenhouse gases suffered another setback Tuesday, when a panel of the U.S. Court of Appeals for the D.C. Circuit invalidated an Obama-era EPA rule governing the use of hydrofluorocarbons (HFCs).

HFCs are a greenhouse gas. They’re less well-known than, say, carbon dioxide, but they still have a warming effect when present in the atmosphere, and the rapid rise of HFC emissions in recent years has been a growing cause of concern for policymakers.

Ironically, HFC use has been encouraged by EPA regulation, which authorizes manufacturers to use HFCs as a replacement for other substances that negatively affect the ozone layer. The regulation struck down this week was EPA’s belated attempt to walk back this legacy, telling companies to forget what it said previously, because HFCs are bad now.

The problem is that the statute EPA claimed gave it the authority to restrict HFCs is about restricting ozone-depleting substances. But as everyone (including the EPA) concedes, HFCs don’t deplete ozone. According to the court, since the EPA had already OK’d manufacturers using HFCs as replacements for actual ozone-depleting substances, it couldn’t use the law governing ozone to bootstrap regulation of HFCs.

All this is somewhat technical, but it raises a broader issue. The EPA’s HFC regulation is one example of a larger strategy adopted by the Obama administration and some in the environmental movement to circumvent Congress when it comes to climate change policies. Instead of working out a viable legislative solution that would deal with the problem, the administration looked for ways to commandeer existing statutory and regulatory provisions as a basis for limiting greenhouse gas emissions. Often, this involved stretching the meaning or purpose of particular provisions until they bore little resemblance to how they traditionally were used. The biggest example of this, of course, was the Clean Power Plan.

Now I can almost hear the shouting as I type these words. Obama had no choice! Republicans in Congress were obstructionists, and never would have passed anything. This overlooks that Democrats controlled the House of Representatives and had a filibuster-proof majority during the first years of Obama’s presidency and still couldn’t enact their climate plan, but let’s leave that aside. My point is this: whatever the rationale of trying to act on climate without Congress, recent events have shown that this is a very fragile strategy.

When the EPA stretches its authority to act without congressional sanction, it risks having its work undone by the courts. And even where an EPA action might survive judicial scrutiny, it is vulnerable to being revoked by a future EPA with a different political bent. What can be done without Congress probably can be undone without Congress. This week’s court decision is simply more evidence that any lasting action on climate is going to have to involve Congress.

Image by Evan El-Amin