Unlike Oreskes, who does not quote even one of the 928 papers upon which her analysis was based, Schulte cites some of the counter-consensual papers from his sample –

Cao et al. (2005) point out that, without the ability to quantify variations in the terrestrial carbon sink both regionally and over time, climate projections are unreliable –

“To predict global climate change and to implement the Kyoto Protocol for stabilizing atmospheric greenhouse gases concentrations require quantifying spatio-temporal variations in the terrestrial carbon sink accurately. During the past decade multi-scale ecological experiment and observation networks have been established using various new technologies (e.g. controlled environmental facilities, eddy covariance techniques and quantitative remote sensing), and have obtained a large amount of data about terrestrial ecosystem carbon cycle. However, uncertainties in the magnitude and spatio-temporal variations of the terrestrial carbon sink and in understanding the underlying mechanisms have not been reduced significantly.”

Gerhard (2004), discussing the conflict between observation, theory, and politics, says –

“Debate over whether human activity causes Earth climate change obscures the immensity of the dynamic systems that create and maintain climate on the planet. Anthropocentric debate leads people to believe that they can alter these planetary dynamic systems to prevent what they perceive as negative climate impacts on human civilization. Although politicians offer simplistic remedies, such as the Kyoto Protocol, global climate continues to change naturally.”

Leiserowitz (2005) reports –

“results from a national study (2003) that examined the risk perceptions and connotative meanings of global warming in the American mind and found that Americans perceived climate change as a moderate risk that will predominantly impact geographically and temporally distant people and places. This research also identified several distinct interpretive communities, including naysayers and alarmists, with widely divergent perceptions of climate change risks. Thus, ‘dangerous’ climate change is a concept contested not only among scientists and policymakers, but among the American public as well.”

Lai et al. (2005) offer an entirely new hypothesis to explain recent warming of the climate –

“The impacts of global warming on the environment, economy and society are presently receiving much attention by the international community. However, the extent to which anthropogenic factors are the main cause of global warming, is still being debated. … This research invokes some new concepts: (i) certain biochemical processes which strongly interact with geophysical processes in climate system: (ii) a hypothesis that internal processes in the oceans rather than in the atmosphere are at the center of global warming; (iii) chemical energy stored in biochemical processes call significantly affect ocean dynamics and therefore the climate system. Based on those concepts, we propose a new hypothesis for global warming.”

Moser (2005) explores the assessment of rising sea levels and in state-level managerial and policy responses to climate change impacts such as sea-level rise in three US states –

“Uncertainties in the human dimensions of global change deeply affect the assessment and responses to climate change impacts such as sea-level rise.”

Shaviv (2006) considers the cosmic-ray forcing posited by Svensmark et al. (2006), and concludes that, if the effect is real, natural climate variability rather than anthropogenic enhancement of the greenhouse effect has contributed more than half of the warming over the past century –

“The cosmic-ray forcing / climate link … implies that the increased solar luminosity and reduced cosmic-ray forcing over the previous century should have contributed a warming of ~0.47K, while the rest should be mainly attributed to anthropogenic causes.”

Zhen-Shan and Xian (2007) say that CO₂ forcing contributes less to temperature change than natural climate variability, that the anthropogenic enhancement of the greenhouse effect –

“Could have been excessively exaggerated” … Therefore, if CO₂ concentration remains constant at present, the CO₂ greenhouse effect will be deficient in counterchecking the natural cooling of global climate in the following 20 years. Even though the CO₂ greenhouse effect on global climate change is unsuspicious, it could have been excessively exaggerated. It is high time to re-consider the trend of global climate changes.”

Whatever “unanimity” may have been thought or claimed to exist before 2004 in the peer-reviewed literature, there is certainly none in the peer-reviewed journals that have been published since.

Is there a scientific “consensus” wider than that defined by Oreskes?

We have established that Oreskes’ essay does not really lend any scientific credibility to the panicky predictions of a small minority of scientists many of whom have Left-leaning political opinions or connections.

The outright scaremongers are led by James Hansen, a donor of thousands of dollars to the re-election campaigns of Al Gore and John Kerry. He showed Congress a graph in 1988 that set the trend for wildly-exaggerated projections of future global temperature.  The graph presented three scenarios, the most extreme of which had no basis in the scientific literature or in previously-observed trends.

Politicians at that time treated the graph with respect because it had been generated by a computer. Yet the model which generated the graph, still in use by Hansen and the UN today, continues to contain “flux adjustments” – i.e. fudge-factors – many times greater than the very small perturbations which the model is supposed to predicting.

Hansen’s graph, updated to depict observed temperature to end 2006 overlaid in red, shows that the temperature trend projected by the GISS model used by Hansen is near-identical to that which the model had projected on the assumption that atmospheric CO2 concentrations had been substantially reduced from 1989 onward and stabilized by 2000. On this evidence (and this is the evidence that launched the “global warming” scare), it would be legitimate to conclude that the additional CO2 that has entered the atmosphere since Hansen’s graph was published has had no climatic influence whatsoever.

Yet Hansen’s computer model, and others very like it, are the chief reason offered by the alarmists for claiming a “consensus” for an extreme version of climate change that even goes so far as to predict the eventual eradication of more than half the world’s species (State of the Wild:  http://www.giss.nasa.gov/~jhansen/preprints/Wild.070410.pdf).

This broader and more frankly alarmist definition of “consensus” that is presented by Hansen, Al Gore, and the BBC has even less warrant in the peer-reviewed literature than the “consensus” to the effect that humankind has caused most of the slight warming of the past half-century. On this definition of “consensus”, we are led to believe that all serious scientists are agreed on the imminence of catastrophe and on the urgent need for, and the likely effectiveness of, costly and extreme mitigative or remedial measures.

It is crucial to appreciate that Oreskes’ paper does not lend any scientific credibility to the alarmists’ extreme views on climate change. The more honest among them recognize how careful she was to constrain the scope of her definition so that at least it bore some relation, however threadbare, to the peer-reviewed literature that she had analyzed. The alarmists, therefore, now find themselves compelled to fall back upon some additional mantras which, if recited often enough, come to seem true.

“2,500 scientists can’t be wrong”

First among these is that the UN’s latest report on climate change (IPCC, 2007) was written by 2,500 scientists – and “2,500 scientists can’t be wrong”. In fact, however, the scientific chapters were contributed by a far smaller number than this. Furthermore, we are now able to offer proof that the UN cannot have obtained the approval of as many as 2,500 scientists to the text before it was published.