One of the most consistent of all the attacks from climate science sceptics and deniers is the one which tries to convince the public that expert scientists are divided on the causes of climate change.

Those attacks have come from ideologically motivated think tanks and the fossil fuel industry, often working together. Only last week, the Wall Street Journal published a polemic to try and mislead the public that a consensus does not exist.

In 1998, the American Petroleum Institute was developing a campaign with the explicit aim of convincing the public that “uncertainties” existed in the science of climate change and its causes.

In 2002, Republican pollster Frank Luntz wrote that: “Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly.”

Several studies have surveyed the views of climate science experts or the scientific literature and have come to the same conclusions — the number of studies and the number of scientists who reject the fact that humans are causing climate change remains vanishingly small.

The latest and most high profile study to survey the scientific literature was led by John Cook, of the University of Queensland’s Global Change Institute and founder of the Skeptical Science website, and published in the journal Environmental Research Letters in May 2013.

Cook et al analysed close to 12,000 global warming studies from 1991 to 2011 to see how many accepted or rejected the fact that human activities are causing climate change. The researchers also asked scientists themselves to look at their own papers and confirm whether they endorsed the scientific consensus.

The central finding, reported widely and even Tweeted by Barack Obama’s campaign team, was that 97 percent of the scientific papers on climate change found that humans were causing it.

Since that study was published, Professor Richard Tol, an economist from the University of Sussex, has been planning to attack Cook’s paper. 

Tol is advisor to the UK climate sceptic group the Global Warming Policy Foundation, founded by Lord Nigel Lawson, who was treasurer to former UK Prime Minister Margaret Thatcher. Tol is also an IPCC lead author but withdrew from the team writing the Summary for Policymakers, claiming the report was “too alarmist”.

Tol accepts that humans cause climate change but his work consistently claims that economic impacts will be small and won’t turn negative until the back end of this century. 

This week, the chairman of the Republican-led US House of Representatives science committee Lamar Smith claimed that Cook’s study had been “debunked” and that the “science is not settled”.

Professor Tol gave evidence to the committee and when he was asked about the 97 per cent figure, he told the hearing: 

“The 97 per cent estimate is bandied about by almost everybody. I had a close look at what this study really did and as far as I can see the study just crumbles when you touch it. None of the statements in the papers is supported by any data that is actually in the papers. It is pretty clear that most of the science agrees that climate change is real and most likely human made, but this 97 per cent is essentially pulled from thin air – it’s not based on any credible research whatsoever.”

Sometime in the coming days, DeSmogBlog understands the journal Energy Policy will publish a paper that claims to debunk Cook et al’s work. The research will inevitably be devoured by conservative media. The author is Richard Tol. 

DeSmogBlog has found the paper was rejected by three journals and heavily criticised by reviewers who saw earlier drafts, who said it had identified “no serious flaws” in the Cook paper, and made some claims that were “not supported by the author’s analyses”.

Cook has told DeSmogBlog that he and his colleagues have found numerous errors.

However, this is unlikely to matter to the world’s conservative media. 

Tol’s attack plan

In June 2013, the month after the Cook et al study was published, Tol commented on a blog that he had “three choices” open to him as a response. 

He wrote these were to either “shut up”, write a “destructive comment” or a “constructive comment”. He wrote that he would opt to make a “destructive comment”.

Tol had also submitted a response to Cook et al to Environmental Research Letters — the same journal where Cook’s original paper was published.

Unusually, Tol published the anonymous comments from the academics who were asked to review his paper.

One reviewer wrote: “I do not see that the submission has identified any clear errors in the Cook et al. paper that would call its conclusions into question – in fact he agrees that the consensus documented by Cook et al. exists.”

Another reviewer comment said Tol’s paper “provides no reason to question the main conclusions of Cook et al.” 

The comment added: “[Tol] merely provides his opinions on where he would have conducted this survey differently and in his view better – and he is free to do just that. But he has not identified serious methodological flaws in Cook et al. that would justify the publication of a Comment.”

In August, Tol wrote to the University of Queensland’s vice-chancellor Professor Peter Hoj to complain about what he claimed were errors in Cook’s methodology.

Tol wanted data that would associate the members of Cook’s team to the scientific papers they had looked at. He wrote that he wanted to find out if the ratings might have been impacted by “fatigue”.

This was the same argument he had made in the first draft of his own paper to Environmental Research Letters (ERL).  One reviewer wrote in response to the “fatigue” hypothesis:

Tol presents no evidence that this is a large problem that would significantly alter the results, though, to the contrary – the numbers he presents suggest it is a small problem that would not significantly alter the conclusion of an overwhelming consensus. 

The University of Queensland released a statement responding to claims that it was trying to block the release of important data connected to Cook’s research.  The university said: 

All data relating to the “Quantifying the Consensus on Anthropogenic Global Warming in the Scientific Literature” paper that are of any scientific value were published on the website Skepticalscience.com in 2013.

Only information that might be used to identify the individual research participants was withheld.

In September 2013, Tol took to Twitter to promote an article written by climate science denialist Lord Christopher Monckton.

In the article, Monckton went on a name-calling spree, describing the Cook et al authoring team among other things as “zit-faces”, “tiddlers” and “intellectual minnows”.

Tol has published the first seven drafts of his paper on his blog. His paper was rejected twice by Environmental Research Letters and was also rejected by two other journals for being “out of scope” before it was finally accepted by the journal Energy Policy.

Tol has also created a slideshow based on his Energy Policy paper where he discusses his claims, despite the fact the paper is not yet published.

In one instance, Tol says he reanalyzed the data in the Cook et al paper and found the consensus figure dropped from 97 percent to 91 percent.

Whether or not Tol has addressed the wide-ranging criticisms of his earlier work, remains to be seen.

Cook told DeSmogBlog that a response to Tol’s paper would be published in the same issue of Energy Policy and would document “a number of critical errors”. He said:

Our finding of 97% consensus on human-caused global warming in relevant climate papers was based on the most comprehensive analysis of peer-reviewed climate papers yet to be conducted. Our result is consistent with previous studies, using different methods, which have independently found 97% agreement amongst climate scientists.

I have been invited by the journal to submit a reply to Professor Tol’s paper, to be published in the same issue. Our reply will document a number of critical errors in Professor Tol’s paper and will be available once his paper has been published.