An investigation into global warming led by a reformed US climate sceptic hasn’t changed the minds of Australia’s own sceptics, but it has reignited the debate over peer-reviewing in climate science.

“Call me a converted sceptic,” declared Richard Muller, a professor of physics at the University of California, in a New York Times op-ed on the weekend. “Last year, after an intensive research effort involving a dozen scientists, I concluded that global warming was real and that previous estimates of the rate of warming were correct. I’m now going a step further: humans are almost entirely the cause.”

The reason for Muller’s turn-around? An investigation led by the Berkeley Earth Surface Temperature project — a project founded by Muller and his daughter Elizabeth — that found average earth temperatures rose 1.5 degrees Celsius over the last 250 years.

It wasn’t exactly ground-breaking for the climate scientists who have long established a pattern of global warming, although Muller called his findings “stronger than those of the Intergovernmental Panel on Climate Change”, the United Nations group that releases global information on climate science.

The BEST study was aimed specifically at a group close to Muller’s heart: sceptics. The Charles G. Koch Foundation, a key backer of climate sceptic think tank the Heartland Institute, even donated US$150,000 to the study. The methods used — avoiding the biases from the urban heat effect, using data from nearly 100% of available temperature stations, examining the quality of each station and limiting human intervention — were directly chosen to address past concerns that sceptics have raised over previous research.

But many Australian sceptics contacted by Crikey are dismissive of Muller. “My recollection is that Muller is regarded as something of an eccentric who is trying to make a name for himself,” Des Moore, the director of the Institute for Private Enterprise, told Crikey. “I do not think much of Muller’s work,” said retired economic adviser and member of the controversial Lavoisier Group Tim Curtin.

Bob Carter, a palaeontologist from James Cook University who was listed as an intended recipient of $1667 a month from the Heartland Institute in leaked documents, added to the criticism: “To assess whether modern temperature change is in any way unusual requires the analysis of long (at least tens of thousands of years) geological climate records — a point completely ignored not only by Muller, but also by the many other persons currently discussing this storm in a teacup.”

Curtin also raises issues with the study’s aims. “One of many absurdities in the Muller op-ed is that there are of course no temperature data for Australia before about 1850 at earliest, nor for Africa and most of the tropics before 1910, so to talk as he does of land surface records of global temperature going back 250 years is worse than misleading,” he said.

It’s solar cycles that are increasing temperature and carbon dioxide, not humans, says Viv Forbes, chairman of The Carbon Sense Coalition. “Solar cycles are tending to suggest a period of cooling is ahead,” he told Crikey. “People will then suddenly discover that life-killing cooling is what we should worry about, not benign warming.”

Herald Sun columnist Andrew Bolt also dismissed the BEST study and claims by the media that Muller was ever a sceptic. Instead fuel has been added to the sceptics’ fire — linked to on Bolt’s blog and many of the sceptics contacted by Crikey also mentioned it —  with the release of a large study by Anthony Watts. Watts is a prominent climate denier blogger at Watts Up and a former television meteorologist. He had previously backed Muller’s methodology, but the two fell out. Instead, his study, which criticises the weather stations across the United States where temperature data is gathered (which Muller’s study touches on), has been impeccably timed to launch with Muller’s research.

“The Muller claims have all the characteristics of public opinion grandstanding, and, as Anthony Watts has shown, are anyway flawed as science,” Carter told Crikey.

Yet of the duelling reports by Muller or Watts, neither study has been published or peer-reviewed.

Ross McKitrick, a professor of economics at the University of Guelph in Canada — and a prominent climate sceptic — was asked by the Journal of Geophysical Research to review part of Muller’s study, a paper by Charlotte Wickham et al examining the results of BEST. McKitrick twice rejected the study because of issues with methodology and decided to place his referee reports online following BEST’s publicity blitz in recent days.

Elizabeth Muller says scientists had critiqued BEST’s findings but added: “I believe the findings in our papers are too important to wait for the year or longer that it could take to complete the journal review process.” Watts plans to submit his study to be peer-reviewed but wanted to publish at the same time as Muller.

It’s become more common for scientists to place studies online before they’ve been published, but this is new in the climate science sphere, an area fraught with criticism. It’s a worrying trend. As Jason Samenow wrote in The Washington Post.

“The Muller and Watts studies no doubt represent a lot of hard work and may eventually prove to be valuable contributions to science. But we should reserve judgment on their significance.

And this new effort by these scientists to grab attention for studies that have not yet been vetted by other, independent scientists is disturbing and unproductive. It’s a disingenuous attempt to score points on a highly polarised scientific issue.”