Allow me, if you will, to grind a familiar ax.

I have devoted many words over the years to arguing that a carbon tax is not some magical climate cure-all (most recently, here and here). It is not the only real, efficacious, or cost-effective climate policy. It is not a reliable way to distinguish who is Serious from who is Unserious about climate change.

It’s a good policy, not the sine qua non, a complement to other policies, not a replacement. We still need tech innovation and deployment, grid investments, emission regulations, and all the rest. There’s no simple answer, no Archimedes’ lever.

Occasionally, I’m accused of caricaturing carbon tax proponents. Surely they’re not as Manichean as all that!

Ahem. I give you this piece from Michael Reilly, editor of MIT Technology Review:

We are familiar with Donald Trump’s stance on climate change: it’s a "con job" perpetrated by the Chinese. His views on energy policy are strongly pro-coal, but also contradict themselves. The Republican Party’s 2016 platform also describes coal as a "clean" source of energy. But the Democratic platform might not be meaningfully better.

Whaaa?

Trump’s energy plan is explicitly and enthusiastically pro–fossil fuels. He would stymie or reverse all of Obama’s climate and energy regulations, accelerate fracking, and somehow (presumably by making good deals) revive the coal mining industry. Oh, and he would pull out of the Paris climate treaty.

Hillary Clinton’s energy plan would expand solar and other clean alternatives. It promises to increase US energy efficiency by a third and decrease US oil consumption by a third within 10 years of her taking office. It aims to meet or exceed the carbon reduction target Obama promised in Paris: 28 percent under 2005 levels by 2025. And it will strengthen international climate commitments.

What rationale could there be for characterizing the latter as "not meaningfully better" than the former?

You guessed it. Clinton’s plan, writes Reilly, "leaves out one big thing: a carbon tax." Thus, "meaningful action on climate change" is "unlikely to come anywhere near conversation for the rest of the 2016 election cycle."

Gah.

It is not clear what "meaningful action" means, or how Reilly intends us to measure it. If it is measured in carbon reductions, well, Clinton has said exactly how much carbon her plan would reduce. Would a carbon tax reduce more?

It obviously depends! A high carbon tax would. A low carbon tax wouldn’t. A revenue-neutral carbon tax that reduces the income tax would be different from a carbon tax that funds clean energy deployment. A static tax set to sunset in a few years would be different from one set to rise year to year, automatically, through midcentury.

The effects of a carbon tax depend entirely on its size and implementation details. The words "carbon tax" do not, in and of themselves, bestow righteousness on a climate plan.

Anyway, as Reilly acknowledges, one way states can comply with Obama’s Clean Power Plan is to join regional carbon markets that put a price on carbon. It’s not like there’s no room for carbon pricing at all in Clinton’s plan; it’s just not a headline.

What’s more, a serious carbon tax is effectively impossible in any Congress Clinton is likely to face. No one — not Clinton, not Sanders, not the risen Jesus — could pass a carbon tax through a Republican House of Representatives.

So it’s not even an actual carbon tax that is alleged to separate meaningful climate policy from mere Trumpism. It is rhetorical support for a carbon tax that is, for all intents and purposes, impossible. It is a purely symbolic gesture.

Maybe Clinton ought to make that symbolic gesture, promise a carbon tax, and lead a fruitless effort to get one at the beginning of her first term, even though she knows in the end she’ll end up using the same executive branch tools Obama used. You could argue that it’s important enough to waste time and political capital on. I don’t agree, but there’s a case to be made.

But the idea that notional support for a doomed carbon tax is meaningful while everything else — all Clinton’s actual plans to take actual action that actually reduces carbon emissions — can be waved away as insignificant ... that’s just carbon tax fetishism at its worst.