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What does Naomi Oreskes' study on consensus show?

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The skeptic argument...

Naomi Oreskes' study on consensus was flawed

The claim of “consensus” rests almost entirely on an inaccurate and now-outdated single page comment in the journal Science entitled The Scientific Consensus on Climate Change (Oreskes 2004). Benny Peiser conducted a search of peer-reviewed literature on the ISI Web of Science database between 1993 and 2003. Dr. Peiser’s research demonstrated that several of the abstracts confounded Oreskes’ assertion of unanimity by explicitly rejecting or casting doubt upon the notion that human activities are the main drivers of the observed warming over the last 50 years. (source: Consensus? What Consensus?)

What the science says...

An examination of the papers that critics claim refute the consensus are found to actually endorse the consensus or are review papers (eg - they don't offer any new research but merely review other papers). This led the original critic Benny Peiser to retract his criticism of Oreskes' study.

In 2004, Naomi Oreskes performed a survey of all peer reviewed abstracts on the subject "global climate change" published between 1993 and 2003. She surveyed the ISI Web of Science database, looking only at peer reviewed, scientific articles. The survey failed to find a single paper that rejected the consensus position that global warming over the past 50 years is predominantly anthropogenic. 75% of the papers agreed with the consensus position while 25% made no comment either way (eg - focused on methods or paleoclimate analysis).

Benny Peiser's rebuttal

Benny Peiser repeated Oreskes survey and claimed to have found 34 peer reviewed studies rejecting the consensus. However, an inspection of each of the 34 studies reveals most of them don't reject the consensus at all. The remaining articles in Peiser's list are editorials or letters, not peer-reviewed studies. Peiser has since retracted his criticism of Oreskes survey:

"Only [a] few abstracts explicitly reject or doubt the AGW (anthropogenic global warming) consensus which is why I have publicly withdrawn this point of my critique. [snip] I do not think anyone is questioning that we are in a period of global warming. Neither do I doubt that the overwhelming majority of climatologists is agreed that the current warming period is mostly due to human impact."

The Viscount Monckton of Benchley's rebuttal

Despite Peiser's retraction, the same argument was repeated by the Viscount Monckton of Benchley (and plagiarised by Schulte). Here are the five studies Monckton claims Oreskes should've included in her survey as rejecting the consensus position:

Multi-resolution time series analysis applied to solar irradiance and climate reconstructions (Ammann 2003) finds a correlation between solar activity and temperature. However, the temperature reconstructions used end in the mid-20th century before the modern global warming trend and don't address the consensus position that warming over the past 50 years is primarily anthropogenic. However, Amman has published a more recent study examining more up-to-date temperature records, concluding "although solar and volcanic effects appear to dominate most of the slow climate variations within the past thousand years, the impacts of greenhouse gases have dominated since the second half of the last century" (Ammann 2007).
Solar Forcing of Global Climate Change Since The Mid-17th Century (Reid 1997) finds a link between solar variability and climate change, concluding that "solar forcing and anthropogenic greenhouse-gas forcing made roughly equal contributions to the rise in global temperature that took place between 1900 and 1955". Considering CO2 forcing before 1955 was much lower while solar forcing was much greater due to increasing solar activity, this conclusion only serves to reinforce the consensus position. More on the sun...
Ad Hoc Committee on Global Climate Issues: Annual Report (Gerhard 2000) is non-peer reviewed. Oreske's survey only included peer reviewed studies. This is even conceded by Schulte.
Atmospheric Greenhouse-Effect in the Context of Global Climate-Change (Kondratyev 1995) is a review, not an article - it doesn't actually include any research but reviews other studies. Oreskes' survey only included articles, not reviews.
Review and impacts of climate change uncertainties (Fernau 1993) is another review, not an article, and is found in the Social Science Citation Index. Oreskes sampled articles only from the Science Citation Index.

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Comments 1 to 3:

thingadonta at 12:42 PM on 20 May, 2009
There is no scientific consensus on the causes of recent (~150 years) global warming amongst scientists. What there is, however, is a continuing distortion of the statistics representing scientific research and opinion.

For one thing, one can't simply report the views of climatologists only, (who generally have a vested interest), but more importantly, this would leave out the greater fields under which climate science is a subset-e.g. earth history and solar science. If you include earth history (i.e. geology etc) and solar scientists etc etc, the figures for 'consensus' always become smaller.

Take for example the idea 'that global warming creates more deserts'. Nice idea to do research on. Climatologists, who are naturally assumed to best answer such a question, then go and gather lots of data, project models, debate, discuss etc etc, and yet don't even bother to consult the past geological record. This would be like a lawyer arguing a case without reference to any case histories. The geological record indicates, that warm periods correspond to less deserts, which is not mentioned in the subsequent climatologist reports. An example is the drying of Africa during the onset of glacial (cooler) periods in the last ~5 Ma, which led to reduced rainforests and more savannah, and the consequent evolution of an upright ape on the savannah-the hominid line (that’s us). But according to the IPCC, Africa does the opposite-it is projected to get drier overall with projected warming, which means, according to the IPCC, we wouldn't even be here.

The statistics and reporting of consensus regarding human-induced climate change has been distorted, similar to what went on in the Soviet Union in the past, eg something like "928 tractor factories were surveyed in the Soviet Union, with 75% supporting the Party's position that production has increased and living standards are better, and 25% are looking more into improving worker conditions, whilst none claim that things have got worse...etc etc". Or to take a more contemporary example, if you asked various USA banks a few years before the recent financial crisis what state their financials were in, what kind of answer do you think you would have got?

The Oreskes report is a gross distortion. Here is a link to all 928 abstracts so you can check them for yourself-http://www.staff.livjm.ac.uk/spsbpeis/Oreskes-abstracts.htm- the vast majority of which are COMPLETELY NEUTRAL as regarding the question of human-induced climate change.

Think of it another way, if you are studying squirrels, and want to do research, what better way than looking into how any climate changes might affect squirrel numbers, dung chemistry of whatever. Note, however, that in this context, there isn’t any 'position' taken on whether or not humans are causing climate change, (or even that it is occurring), something which such a study couldn't answer. The vast majority of the 928 abstracts fall into this 'neutral' category. To say that “none of the papers disagree with the consensus position” (i.e. human-induced global warming), is a gross distortion; a small percentage have come to stronger conclusions which question it, and a small percentage have come to stronger conclusions which support it (the relative proportions for both cases is difficult to put a figure on, because the data, by its very nature, is ambiguous), but the point is, the vast majority are not even attempting to answer the question.
thingadonta at 22:12 PM on 8 August, 2009
In your Peiser 'retraction' link and quote you have misrepresented what he is saying. Here is the longer version (from which you have cherry-picked/distorted) of what he said:

"I do not think anyone is questioning that we are in a period of global warming. Neither do I doubt that the overwhelming majority of climatologists is agreed that the current warming period is mostly due to human impact. However, this majority consensus is far from unanimous.
Despite all claims to the contrary, there is a small community of sceptical researchers that remains extremely active. Hardly a week goes by without a new research paper that questions part or even some basics of climate change theory.

(For the latest developments, see http://greenspin.blogspot.com/2006/10/do-i-detect-first-tiny-rumblings-of.html)

Undoubtedly, sceptical scientists are a small minority. But as long as the possible impacts of global warming remain uncertain, the public is justified to keep an open mind. How decision-makers deal with these scientific uncertainties is another matter. But it is vital for the health and integrity of science that critical evaluation and scepticism are not scorned or curbed for political reasons."

http://www.abc.net.au/mediawatch/transcripts/ep38peiser.pdf
thingadonta at 22:20 PM on 8 August, 2009
Another example of misrepresentation of what Peisner said, from the same source you quoted:

"Please note that the whole ISI data set includes just 13 abstracts (less than 2%) that *explicitly* endorse what she has called the 'consensus view.' The vast majority of abstracts do not deal with or mention anthropogenic global warming whatsoever. I also maintain that she ignored a few abstracts that explicitly reject what she calls the consensus view. You can check for yourself at http://www.staff.livjm.ac.uk/spsbpeis/Oreskes-abstracts.htm"

You 'conveninently' left this statement, and others like it, by Peisner out.

reference: http://www.abc.net.au/mediawatch/transcripts/ep38peiser.pdf.