Free speech is great, insist many on the left — unless you happen to believe X, Y or Z — in which case, you should probably be punished (or jailed!) for voicing that opinion.

As BRENDAN O’NEILL argues in an excerpt from his new book, “A Heretic’s Manifesto: Essays on the Unsayable,” (London Publishing Partnership, out now) nowhere is that rigid intolerance more apparent than in our discussion on climate change, wherein only one opinion is correct — and any other points of view are deserving of the wrath of God.

There may not be witch trials in the 21st-century West, but there is certainly the dream of witch trials.

Especially for those who have the temerity to use their tongues to deny the existence of manmade climate change.

As one academic study asks: “Deceitful tongues: is climate-change denial a crime?”

This is Biblical language, literally. Right out of Psalms. “Thou lovest evil more than good; and lying rather than to speak righteousness. Thou lovest all devouring words, O thou deceitful tongue,” says Psalms 52:3-4.

Now such stern religious condemnation is deployed against questioners of the climate-change thesis.

The author of that piece on the “deceitful tongues” of the modern age — William C. Tucker, then an assistant regional counsel to the US Environmental Protection Agency, no less — said such tongues may indeed need to be silenced.

For what they say is not only “morally repugnant,” but potentially criminal, too: “[We] cannot allow fraudulent or deceptive speech to paralyze the public debate on a subject no less important than the survival of the human species and the future of the Earth itself.”

In the past, witches, likely including those who were accused of raising “hurtful weather,” were sometimes fitted with a “scold’s bridle” — a metal contraption that enclosed the head and which contained a muzzle that fitted into the mouth with a spike that would compress the witch’s “vicious tongue.”

Now, being more modern, we prefer to propose mere criminal sanctions against those who possess a
“deceitful tongue.”

The tyranny of holding mass witch trials may no longer be possible in our more civilized era, but the fantasy of such tyranny still exists.

“I wonder what sentences judges might hand down at future international criminal tribunals on those who will be partially but directly responsible for millions of deaths from starvation, famine and disease in decades ahead,” environmentalist author Mark Lynas once said.

Who are the “those” in that chilling sentence? Climate-change deniers, of course, who will “one day have to answer for their crimes,” according to Lynas.

Paul Krugman of the New York Times describes climate-change denial as “a form of treason — treason against the planet.”

The Kennedy Institute of Ethics at Georgetown University openly ponders whether climate-change denial should be criminalized.

Yes, “free speech is one of the most treasured rights in Western democracy,” it says in its discussion of a Norwegian professor’s suggestion that climate-change denial is a crime, but sometimes we make “exceptions for points of view which [may be regarded] as particularly destructive and evil.”

Evil. What a telling word.

As clear a confirmation as one could ask for that the discussion of climate change has been hyper-moralized, turned from a practical matter of how to improve our environment into a crusade against the malevolent forces whose deceitful tongues and activities allegedly wreak havoc upon the weather.

Of course, it isn’t only powerful “climate criminals” who are held responsible for contrary weather today — we all are.

We are living through a collectivization of the witch trial, where all human beings, by mere dint of existence, are said to be contributing to climatic instability.

Every weather anomaly is now instantly laid at the feet of humanity. “With raging wildfires, floods and pandemics, it seems like End Times — and it’s our own damned fault,” said a writer for The Hill in July 2021.

A Guardian account of the IPCC’s sixth and most recent assessment report said we now finally have the “verdict on [the] climate crimes of humanity” — we are “guilty as hell.”

Professor Tim Palmer of Oxford University draws a direct line between man’s allegedly sinful behavior and various floods and fires across the globe.

“If we do not halt our emissions soon, our future climate could well become some kind of hell on Earth,” he says.

This view of humankind’s weather crimes helping to raise hell to the surface echoes the demonology of
James VI, who believed witches were induced by “all the devils in hell” to commit their storm-raising and other offenses.

There is a powerful Old Testament overtone to much of the discussion about climate in the 21st century.

Fires and floods are viewed as warnings to humankind about its unholy behavior.

Australia’s bushfires “are a warning to the world,” said a climate activist in the Guardian in January 2020.

Fires in Europe in summer 2022 were described by some as an “apocalypse of heat.”

“Hell is coming,” said a Guardian headline.

This is “apocalypse now,” we were told, and it’s a result of our “living beyond our means,” which is “the greatest sin of all time.”

Floods are likewise cited as reprimands from Mother Nature for our sins.

Large rainfalls in the UK in 2007 were described by one green businessman as “the drumbeat of disaster that heralds global warming.”

It feels as though “behind the gathering clouds the hand of God is busy, writing more bills [for humankind],” he said.

Mark Lynas has also described weather anomalies as god-like chastisements of industrious mankind.

He said of floods that Poseidon is clearly “angered by arrogant affronts from mere mortals like us”: “We have woken him from a thousand-year slumber and this time his wrath will know no bounds.”

This idea that weather has a punishing intent, that it is violent payback for the “affronts” of mankind, also echoes the more hysterical moments of the Little Ice Age.

As Philipp Blom documents, alongside singling out covens of witches as the harbingers of climatic mayhem, religious figures also presented contrary weather as an expression of divine “displeasure.” “Every earthquake, every volcanic eruption and every storm was interpreted as … a punishment for human wickedness,” writes Blom. A “direct causal link between bad behavior and bad harvests” was frequently made.

Indeed, in the 1500s and 1600s, “weather sermons became a minor literary genre of their own,” he says. One particularly skilled practitioner of the “weather sermon” was Johann Georg Sigwart, a German theologian.

“There is little more heretical today than to question the climate-change narrative.”

Brendan O’Neill

In 1599, in a weather sermon delivered in the city of Tübingen, Sigwart told the assembled that “the Almighty has exercised his merciful will here.”

The only solution to the climatic crisis, he said, was for “every man [to] arrive at honest repentance,” which might “move our Heavenly Father to… make these punishments less severe.”

Weather sermons are back in fashion. Only they aren’t a “minor literary genre” anymore — they’re the cash cow of publishing houses and film studios.

Books with titles like “Angry Weather: Heatwaves, Floods, Storms and the New Science of Climate Change,” “The Last Generation: How Nature Will Take Her Revenge for Climate Change” and
“The Uninhabitable Earth: Life After Warming” confirm that “theological interpretations of climatic events” — as Blom describes the Little Ice Age’s view of anomalous weather — are thriving once more.

And, again, the demand is made of us to “repent” in order that we might make not God’s punishments, but nature’s punishments “less severe.”

In September 2021, Pope Francis and the Archbishop of Canterbury, Justin Welby, issued a joint statement saying humankind now has “an opportunity to repent” for our failure to “protect and preserve [nature].”

A year later, Francis returned to the theme. Mankind must “repent and modify our lifestyles” if we are to preserve “our common home,” he said.

It isn’t only religious leaders who use this Little Ice Age language.

Secularist greens do, too.

One green writer once congratulated former climate-change skeptics in the media for having “recanted” and accepted the truth of “climate chaos.” Recant — there it is, the fierce religious pressure of the past rehabilitated for a modern audience.

To recant is to say one no longer holds an opinion or belief, especially one that is heretical.

And there is little more heretical today than to question the climate-change narrative.

Brendan O’Neill is chief political writer for the British online magazine spiked. His new book, “A Heretic’s Manifesto: Essays on the Unsayable,” is available now.