Paul Krugman investigates one of the great mysteries of our day in his Monday column. Why, in the face of devastating consequences that are already upon us, is it so hard to take action to curb man-made global warming?

The venerable economist considers the usual suspects, and pretty much discounts them. Instituting emission controls will cause minimal economic harm. Even the anti-science U.S. Chamber of Commerce, try as they might, only found modest costs to carbon reductions. Is it the power of vested interests? he wonders.

I’ve been looking into that issue and have come to the somewhat surprising conclusion that it’s not mainly about the vested interests. They do, of course, exist and play an important role; funding from fossil-fuel interests has played a crucial role in sustaining the illusion that climate science is less settled than it is. But the monetary stakes aren’t nearly as big as you might think.

What about the coal workers? Won't they be hurt? More like the coal owners.

Krugman points out that the truth is that there are very few coal-mining jobs left.

Once upon a time King Coal was indeed a major employer: At the end of the 1970s there were more than 250,000 coal miners in America. Since then, however, coal employment has fallen by two-thirds, not because output is down — it’s up, substantially — but because most coal now comes from strip mines that require very few workers. At this point, coal mining accounts for only one-sixteenth of 1 percent of overall U.S. employment; shutting down the whole industry would eliminate fewer jobs than America lost in an average week during the Great Recession of 2007-9. Or put it this way: The real war on coal, or at least on coal workers, took place a generation ago, waged not by liberal environmentalists but by the coal industry itself. And coal workers lost.

Having dispensed with some of the usual suspects, Krugman wonders if the ideology of Ayn Rand libertarianism that is so popular amongst conservative politicians, policy makers and commenters could be at the core of the anger over environmental regulation. Think about global warming from the point of view of someone who grew up taking Ayn Rand seriously, believing that the untrammeled pursuit of self-interest is always good and that government is always the problem, never the solution. Along come some scientists declaring that unrestricted pursuit of self-interest will destroy the world, and that government intervention is the only answer. It doesn’t matter how market-friendly you make the proposed intervention; this is a direct challenge to the libertarian worldview. And the natural reaction is denial — angry denial. Read or watch any extended debate over climate policy and you’ll be struck by the venom, the sheer rage, of the denialists. Then there is anti-intellectualism strain that runs through American life—especially on the right—the tendency to believe in conspiracy theories, like the one about how all the world's scientists are in on the gigantic climate hoax, Krugman points out. Taken together, libertarianism plus anti-intellectualism equals toxic mix, or as Krugman concludes.