Analysis of Cook’s (of SkepticalScience.com) 97% claim:
Of 12280 papers, Cook took out the “Don’t Knows”(66% of the samples), and in, essence
counted all of the remainder that did not reject the hypotheses that humans are
causing global warming as endorsing the “consensus”.
Had he included the “Don’t Knows”, it would be: “32% endorsed the consensus position
that humans are causing global warming.”
Had he included ONLY explicit endorsement, it would be: “8% endorsed the consensus
position that humans are causing global warming.”
We analyze the evolution of the scientific consensus on anthropogenic global warming
(AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts
from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We
find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7%
rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts
expressing a position on AGW, 97.1% endorsed the consensus position that humans are
causing global warming.
The Cook paper is remarkable for its quality, though. Cook and colleagues studied
some 12,000 papers, but did not check whether their sample is representative for
the scientific literature. It isn’t. Their conclusions are about the papers they
happened to look at, rather than about the literature. Attempts to replicate their
sample failed: A number of papers that should have been analysed were not, for no
... The sample was padded with irrelevant papers. An article about TV coverage on
global warming was taken as evidence for global warming. In fact, about three-quarters
of the papers counted as endorsements had nothing to say about the subject matter.
As Tol explains, the Cook et al paper used an unrepresentative sample, can’t be replicated,
and leaves out many useful papers. The study was done by biased observers who disagreed
with each other a third of the time, and disagree with the authors of those papers
nearly two-thirds of the time. About 75% of the papers in the study were irrelevant
in the first place, with nothing to say about the subject matter. ... Cook himself
has admitted data quality is low. He refused to release all his data, and even threatened
legal action to hide it. (The university claimed it would breach a confidentiality
agreement. But in reality, there was no agreement to breach.)
They surveyed 10,257 Earth Scientists, 3146 responded.
Then they selected 77 responses from published climate scientists to get the 97.4%
claim. Of course most published climate scientists make a living from alarmism -
there is little money to research non-alarmist climate.
According to American Meteorological Society (AMS) data, 89% of AMS meteorologists
believe global warming is happening, but only a minority (30%) is very worried about
In contrast to the AMS survey, where all respondents are AMS meteorologists, a majority
have Ph.D.s and fully 80% have a Ph.D. or Masters Degree, position statements by
organizational bureaucracies carry little scientific weight. For example, a position
statement recently published by the National Academy of Sciences (NAS) and frequently
cited as the “definitive” indication of scientific consensus on global warming was
authored by a mere 23 persons. Of those 23 persons, only five had Ph.D.s in a field
closely related to climate science, an equal number (5) were staffers for environmental
activist groups, two were politicians, one was the EPA general counsel under the
Clinton administration and 19 of the 23 had already spoken out on behalf of global
warming alarmism prior to being chosen for the panel. Clearly the scientific weight
of the NAS statement pales in comparison to the AMS meteorologist survey.