In a previous blog, I outlined the role that a UK newspaper, the Daily Mail, had played in a recent demonstration of the distorting and amplifying effects of the echo chamber of climate change denial.
The newspaper's contribution had been to publish on its website an article by Ted Thornhill that misrepresented a new research paper by Dr Zunli Lu and co-authors about the Medieval Warm Period, which was subsequently reproduced by other 'sceptic' blogs and media outlets.
But I omitted some interesting details that cast new light on the tactics the newspaper uses to promote public confusion about climate change.
I should have made clear that the inaccurate and misleading article was never published in the printed Daily Mail, but only appeared on its sister website, the Mail Online.
On 6 February, while giving evidence to the Leveson Inquiry into the culture, practice and ethics of the Press, Paul Dacre pointed out that although he is the editor of the Daily Mail and editor-in-chief of the Mail Group titles (including the Mail on Sunday), the Mail Online has its own editor, Martin Clarke.
During his testimony, Mr Dacre also claimed:
"The beauty of the Mail Online is that it doesn't have to carry many apologies because it corrects things instantly. It gets the complaint and changes it immediately, either drops the article, carries a correction - instantly."
This provides interesting background to the article by Mr Thornhill, which was originally published by the Mail Online at 12:21 pm on 26 March and very quickly disseminated by climate change 'sceptics', including Lord Lawson's Global Warming Policy Foundation which posted a reproduction on its own website at 8:55 am on 27 March.
But on 28 March, Syracuse University published a short statement by Dr Lu complaining that his research paper had been misrepresented by Mr Thornhill's article. Two days later, at 12:52 pm on 30 March, Mr Thornhill's article was updated, introducing some amendments to make it less inaccurate and misleading.
For instance, the original article's claim that the research "means that the Earth has already experienced global warming without the aid of CO2 emissions" was removed from the fourth paragraph and, further on, a new sentence was added: "Lu says that his research has no direct bearing on the current climate, and points out that his research is restricted to one area of Antarctica, and is not in itself proof that the whole Earth warmed up".
The updated version, although ignored by those 'sceptics' who had regurgitated the original, represented an admission that the Mail Online had been wrong. However, the corrections were only partial and the article, particularly its headline and opening paragraph, remained inaccurate and misleading.
However, a more recent article published by the Mail Online shows that Mr Thornhill's article was part of an apparently concerted effort to create doubt among readers that emissions of carbon dioxide and other greenhouse gases are driving global warming.
On 4 April, the Mail Online published an article under the headline 'Could space dust be at fault for climate change? New research links particles in space to ever changing weather conditions'.
The opening paragraph stated: "Cosmic dust that fills space could be playing a part in climate change according to new scientific research".
The original source for this article was a media release issued by the Royal Astronomical Society (RAS) on 29 March, announcing the initiation of a new research project. But nowhere does it mention climate change. The lead researcher, Professor John Plane, told me the following in an e-mail message:
"The headline of this article is completely misleading, and bears no relation to what the article actually says, or was in the RAS press release on which it is based. It is a pity that the Mail did not contact me to check it."
Verity Payne of Carbon Brief has suggested that the Mail Online article might be based not on the original media release on the website of the Royal Astronomical Society, but instead on a version posted on the Daily Galaxy website under the headline: 'EcoAlert: Does Cosmic Dust Play a Role in Climate Change?'
This could indeed be true, particularly as the author of the Mail Online article was by-lined as "Daily Mail Reporter". As Paul Dacre explained during his testimony to the Leveson Inquiry (while, ironically, defending another inaccurate and misleading Mail Online article headed 'Cancer danger of that night-time trip to the toilet'), this by-line is used for any article that has been copied from another source and tweaked by a Mail staff member before publication:
"Actually it's a layout device to break that line, if you put a Daily Mail reporter on a story that possibly came in from an agency and the Daily Mail reporter might have put a -- would change some of it."
It is quite clear that the editor and news desk of the Mail Online instruct reporters to recycle 'sceptical' stories from news wires and other websites, and will even re-write the headline and body of an article to make it comply with the editorial line. In this case, the editorial line appears to be to create doubt in readers' minds about the link between greenhouse gas emissions and climate change, even if it means blatantly misrepresenting scientific research.
And one should not underestimate the extent of the damage to the public interest that the Mail Online could be causing through its misinformation campaign - it reaches a readership of more than 45 million worldwide every month, higher than any other newspaper.
Bob Ward is policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science.