Grist, a website for environmentalists, reports that the science forum of Reddit has "banned climate deniers", as the article so delicately puts it. The headline writers wonder if other media outlets shouldn't follow suit. Having read the article though, there is rather less to this than meets the eye, and it doesn't actually seem that there is a blanket ban at all:

The answer was found in the form of proactive moderation. About a year ago, we moderators became increasingly stringent with deniers. When a potentially controversial submission was posted, a warning would be issued stating the rules for comments (most importantly that your comment isn’t a conspiracy theory) and advising that further violations of the rules could result in the commenter being banned from the forum. As expected, several users reacted strongly to this. As a site, reddit is passionately dedicated to free speech, so we expected considerable blowback. But the widespread outrage we feared never materialized, and the atmosphere greatly improved.

This seems mostly reasonable to me. If people are being rude or bonkers then by all means tell them not to and if they persist then ban them. There is, however, a problem in defining what is bonkers or a conspiracy theory. So when the author of the piece, Nathan Allen, writes of people accusing "hard-working scientists whose research supported and furthered our understanding of man-made climate change of being bought by “Big Green”, one should remember that some apparently hard-working scientists have been bought by big green or are simply fully paid-up members of the green movement. Not all, or even most, certainly, but the political motivations of some within the scientific community are hard to avoid. One can also recall incidents like the Climategate email in which a green group circulated scientists looking for someone to write a paper to link the French heatwave of 2003 to global warming, and also Sarah Mukherjee's comments about most climate science being paid for by greens.

So there are issues of judgement to be made over what constitutes a conspiracy theory and what is legitimate criticism. Over the piece then, we have what should be a reasonable approach, provided it is put into action with a bit of thought and suitable humility about the scientific endeavour and a clear-eyed recognition of the human failings of scientists.

Oh yes, and Allen needs to get his own house in order before he accuses others of conspiracy theorising.