Scientific knowledge is always in a state of flux; there is simply no such thing as "settled science", peer reviewed or otherwise.
THE Intergovernmental Panel on Climate Change is a branch of the UN that advises governments on the topic of global warming allegedly caused by human greenhouse emissions.
Contrary to common assumption, the IPCC does not deal with the wider topic of climate change in general. And neither is it the role of the scientists who advise the IPCC to conduct new research as such (though some, incidentally, do).
Rather, the IPCC's task is to summarise the established science as represented in the published scientific literature.
On February 3, 2010, Rajendra Pachauri, head of the IPCC, commenting in The Hindu on the IPCC's 2007 Fourth Assessment Report, said: "Everybody thought that what the IPCC brought out was the gold standard and nothing could go wrong."
By "gold standard", Pachauri was referring to the IPCC's oft-made claim that the scientific literature on climate change it surveyed was only that published in peer-reviewed professional research papers.
Interestingly, Albert Einstein's famous 1905 paper on relativity was not peer reviewed. It is therefore quite clear peer review is not a precondition for excellent, indeed epoch-making, scientific research.
Peer review is a technique of quality control for scientific papers that emerged slowly through the 20th century, achieving a dominant influence in science after World War II.
The process works like this: a potential scientific author conducts research, writes a paper on their results and submits the paper to a professional journal in the relevant specialist field of science.
The editor of the journal then scan-reads the paper. Based on their knowledge of the contents of the paper, and of the activities of other scientists in the same research field, the editor selects (usually) two people, termed referees, to whom he sends the draft manuscript of the paper for review.
Referees, who are unpaid, differ in the amount of time and effortthey devote to their task of review. At one extreme a referee will criticise and correct a paper in detail, including making comments on the scientific content. At the other extreme, a referee may merely skim-read a paper, ignoring obvious mistakes in writing style or grammar, and make some general comments to the editor about its scientific accuracy or otherwise.
Generally neither type of referee, nor those in between, check the original data, or the detailed statistical calculations (or, today, complex computer modelling) that often form the kernel of a piece of modern scientific research.
Each referee recommends whether the paper should be published (usually with corrections) or rejected, the editor making the final decision.
In essence, traditional peer review is a technique of editorial quality control, and that a scientific paper has been peer reviewed is absolutely no guarantee the science it portrays is correct.
Indeed, it is the nature of scientific research that nearly all scientific papers are followed by later emendation, or reinterpretation, in the light of new discoveries or understanding.
A case in point is the recent paper by University of Melbourne researcher Joelle Gergis and co-authors that claimed to establish the existence of a southern hemisphere temperature "hockey stick". Now, the authors have rapidly withdrawn the study after fundamental criticisms of it appeared on Steve McIntyre's Climate Audit blog and elsewhere.
The Gergis paper differs in kind from many other IPCC-related studies by establishment climate research groups only in that the tendentious science it contains has been rapidly exposed as flawed. This exemplifies how the role of nurturing strong and independent peer review has now passed from the editors of journals to experts in the blogosphere, and especially so for papers concerned with perceived environmental problems such as global warming.
Scientific knowledge, then, is always in a state of flux; there is simply no such thing as "settled science", peer reviewed or otherwise. During the latter part of the 20th century, Western governments started channelling large amounts of research money into favoured scientific fields, prime among which has been global warming research.
This money has a corrupting influence, not least on the peer-review process.
Many scientific journals, including prestigious ones, are captured by insider groups of leading researchers in particular fields. In such cases, editors deliberately select their referees from scientists who work in the same field and share similar views.
The "climategate" email leak in 2009 revealed this cancerous process is at an advanced stage of development in climate science. A worldwide network of leading climate researchers was revealed to be actively influencing editors and referees to approve for publication only research that supported the IPCC's alarmist view of global warming and to prevent the publication of alternative views.
Backed by this malfeasant system, leading researchers who support the IPCC's red-hot view of climate change endlessly promulgate their alarmist recommendations as "based only upon peer-reviewed research papers", as if this were some guarantee of quality or accuracy.
Peer review, of course, guarantees neither. What matters is not whether a scientific idea or article is peer reviewed, but whether the science described accords with empirical evidence.
So what about the IPCC's much-trumpeted, claimed "gold standard" of only using peer-reviewed papers? It is completely exposed by Canadian investigative journalist Donna Laframboise, who showed an amazing 30 per cent of the articles cited in the definitive Fourth Assessment Report of the IPCC were from non-peer-reviewed sources, including student theses and environmental lobbyist reports.
The repetition of the "we only use peer-reviewed information" mantra that is so favoured by climate lobbyists and government-captive scientific organisations signals scientific immaturity.
It also indicates a lack of confidence or ability to assess the scientific arguments about dangerous global warming on their own merits and against the empirical evidence.
Bob Carter is a palaeoclimatologist at James Cook University, Townsville and an emeritus fellow of the Institute of Public Affairs. He is a member of the GWPF's Academic Advisory Council.