This is a dangerous and slightly desperate trend, because it tends to remove climate science from the climate change debate. It also preys on journalists' darkest fears: that the scourge of censorship, once unleashed, will invade every aspect of their practice.
The most recent outcry in defence of climate change denial arose when the prestigious UK science body, the Royal Society, made the unusual public gesture  of demanding that ExxonMobil stop funding organizations that attack the climate change consensus.
In some quarters, this was immediately condemned as an attempt at censorship, as proof that intolerant "greens" were bullying the biggest and most profitable corporation in the world.
You'll notice, though, that the Royal Society was not arguing against an Exxon investment in contrarian research - only in contrarian argument. And the basis for the Royal Society's position was that, according to its understanding of the facts, the Exxon-sponsored contrarians weren't offering up an interesting difference of opinion. They were saying things that are, flatly, not true. And they appeared to be saying them because it increased immeasurably the likelihood that they would get funding from Exxon and its confederates among energy industry companies and energy profit-derived think tanks.
The Royal Society complained, in effect, that what Exxon was doing constitutes an offence to science. That, I would argue, is a position that the Royal Society is particularly well-positioned to take.
This also points to an elemental weakness in the position of those who try to cast this as a free-speech issue. They want carte blanche for contrarians to deny the science behind climate change (without having to justify their position with a compelling scientific argument); but while allowing the denial position to run unfettered, the contrarians would deny the Royal Society the right to try to shout down the charlatans. It's okay for someone with negligible credentials in the field - someone like Dr. Tim Ball, for example - to launch a career as a contrarian speaker, but it's not okay when one of the most august scientific bodies in the world cries foul.
The censorship aspect - the journalistic nervousness about denying certain well-heeled constituents their place in the news - is also rooted in fallacy. Journalists tend to believe that they are offering a full and fair accounting of the issues of the day. Regardless of the increasing corporatization and concentration of media ownership, individual journalists still believe that they are objectively representing a fair cross section of the news.
It's fair to say that they are giving it a good shot. But it's naive to think that they are not being manipulated and managed. And it would be plain wrong to think that the people who are most successful at organizing that manipulation are stodgy scientists from the Royal Society, or even fiendishly clever environmentalists.
The people who are most effective at feeding the media's appetite are the people who can most easily afford to do so: ExxonMobil, for instance. It's time that journalists made an effort to learn more about public relations - about the way they are used and abused.
For full flavour of this free-speech argument, you can look here at the UK website Spiked . It's a little over the top, and the writer, Brendan O'Neill, tends to fall on his sword when he starts defending U.S. President George W. Bush's post 9/11 credo - "You're either with us or against us" - against the Royal Society's caution to Exxon.
"If anything, the green’s black-and-white divide is worse than Bush’s. At least his was based on some kind of values, allowing us the opportunity to say yes or no to them; the green’s divide is based on ‘facts’, which means that those who decide that they are ‘against’ rather than ‘with’ can be labelled liars, deniers or crackpots like moon-landing conspiracy theorists or anti-Semitic historians.There is this anti-intellectual retreat into values - into areas where information is irrelevant. That's a bad approach to public policy, but a devastatingly silly approach to science, in which facts, and even "fatalistic facts" are - or should be - at the root of every discussion.
Finally, there is, once again, the question of whether calling someone a denier necessarily puts them into a category with people who deny the Holocaust.
The point seems to be missed over and over. If you say "no, that's wrong" and you have data - you have alternatives that are being tested and not just pulled out of an old textbook or made up - then that can legitimately be regarded as research, which may or may not add something useful to the conversation. If, instead, you foresake research in favour of a series of public lectures in which you wave your arms and deny climate change purely on the basis of outdated or irrelevant references, then that is just denial.
And if, when someone points it out, you think that puts you in bad company, that's your own affair.