Are climate-change deniers guilty of treason?

It seems as though the so-called skeptics have really gotten under Paul Krugman's skin this time. Writing in his New York Times column Sunday, the Nobel Prize-winning liberal economist expressed outrage at the representatives who voted against the Waxman-Markey climate-change bill because they doubted the scientific basis of global warming. He writes:

And as I watched the deniers make their arguments, I couldn’t help thinking that I was watching a form of treason — treason against the planet.

Mr. Krugman then gives a rundown of the latest climate research, whose predictions are far worse than previously thought. He describes climate change as a "clear and present danger" – borrowing a phrase first deployed in 1919 by Supreme Court Justice Oliver Wendell Holmes, Jr. to imprison a man for opposing the draft – and concludes:

Still, is it fair to call climate denial a form of treason? Isn’t it politics as usual?

Yes, it is — and that’s why it’s unforgivable.

Do you remember the days when Bush administration officials claimed that terrorism posed an “existential threat” to America, a threat in whose face normal rules no longer applied? That was hyperbole — but the existential threat from climate change is all too real.

Yet the deniers are choosing, willfully, to ignore that threat, placing future generations of Americans in grave danger, simply because it’s in their political interest to pretend that there’s nothing to worry about. If that’s not betrayal, I don’t know what is.

As Krugman suggests, recent years have seen the bar set pretty low for what can get a person branded as a traitor. In a February 2003 editorial, the now-defunct New York Sun called for police to monitor protesters opposing the invasion of Iraq "with an eye toward preserving at least the possibility of an eventual treason prosecution," for giving "aid and comfort to the enemy," a crime that in the United States carries the death penalty.

A few months later saw the release of a bestselling book by conservative commentator Ann Coulter (who, incidentally, holds a law degree), that insisted that all American liberals – that is, about one fifth of the US population – are guilty of treason. Those who peacefully opposed the war were similarly maligned throughout the burgeoning right-wing wilds of the blogosphere, and were, it should be noted, extensively spied on by the US government.

So now a few environmentalists have envisioned the state wielding its coercive power against those who doubt that humans activity is destabilizing the Earth's climate.

James Hansen, who heads NASA's Goddard Institute for Space Studies and is regarded as one of the world's leading climate scientists, last year called for CEOs of oil companies to be put on trial for crimes against humanity for their well-documented efforts to spread doubt about global warming.

In a similar vein, in 2006 British journalist and environmental activist Mark Lynas, whose book, Six Degrees: Our Future on a Hotter Planet, plausibly details how climate change could unleash a major extinction event, imagined a future climate court putting the deniers on trial. He writes:

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. I put this in a similar moral category to Holocaust denial – except that this time the Holocaust is yet to come, and we still have time to avoid it. Those who try to ensure we don’t will one day have to answer for their crimes.

His equation of climate change doubters to Nazi apologists was echoed that year by Grist's David Roberts, who called for "some sort of climate Nuremberg" to hold the deniers accountable.

According to Guardian environmental columnist Leo Hickman, climate-change deniers love this kind of rhetoric, because it portrays them as  "brave, 'truth'-wielding Galileos standing up against a wave of pseudo-scientific indoctrination." Writing in response to Krugman's column, Mr. Hickman says that deniers faced with accusations of treaon will inevitably "trot out the predictable comparisons to the Salem witch trials and McCarthyism."

Of course, it's only a small fraction of environmentalists who have openly called for jail time – or worse – for climate-change deniers. After all, the environmental movement has benefited tremendously from laws that protect freedom of expression. Far more importantly, refraining from "hanging" people for what they say – even if you believe that what they say amounts to a destructive campaign of disinformation  –  is a hallmark of civilized society.